Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| catalysis and ligand binding by thymidylate synthase immobilized on thiopropyl-sepharose 6b. | lactobacillus casei thymidylate synthase, which employs the thiol of cysteine-198 as a covalent catalyst, was reversibly coupled to thiopropyl-sepharose 6b through the catalytic sulfhydryl group of one of its two subunits, yielding an immobilized heterodimeric form of the enzyme possessing one free active site and one covalently modified active site. enzyme inactivated by treatment with n-ethylmaleimide, which selectively modifies the active site cysteines but not the remaining cysteines (cys-24 ... | 1992 | 1421618 |
| 13c nmr studies of complexes of escherichia coli dihydrofolate reductase formed with methotrexate and with folic acid. | 13c nmr studies of 13c-labelled ligands bound to dihydrofolate reductase provide (dhfr) a powerful means of detecting and characterizing multiple bound conformations. such studies of complexes of escherichia coli dhfr with [4,7,8a,9-13c]- and [2,4a,6-13c]methotrexate (mtx) and [4,6,8a-13c]- and [2,4a,7,9-13c]folic acid confirm that in the binary complexes, mtx binds in two conformational forms and folate binds as a single conformation. earlier studies on the corresponding complexes with lactobac ... | 1992 | 1426244 |
| [phosphoenolpyruvate:hexose phosphotransferase systems in lactobacillus species]. | the substrate range of phosphoenolpyruvate:hexose phosphotransferase systems (hexose-ptss) in lactobacillus casei subsp. casei lac3 and l. acidophilus lac5 was examined. strain lac3 demonstrated pts activities for glucose (glc), mannose (man), glucosamine (gcn), 2-deoxyglucose (2dg) and fructose (fru), while strain lac5 showed the activities only for man and fru. these activities were all constitutive. growth of both strains was strongly inhibited by 2dg. 2dg-resistant mutants dg329 and dg504 we ... | 1992 | 1433910 |
| inhibition of shigella sonnei by lactobacillus casei and lact. acidophilus. | the protective effect of feeding milk fermented with a mixture of lactobacillus casei and lact. acidophilus against shigella sonnei was studied. there was a 100% survival rate in mice fed for 8 d with fermented milk and then dosed orally with sh. sonnei. the survival rate in control mice was approximately 60% after 21 d. colonization of the liver and spleen with sh. sonnei was markedly inhibited by pretreatment with fermented milk. differences in cell counts of 2-3 log units between treated and ... | 1992 | 1447056 |
| prevention of 5-fluorouracil-induced infection with indigenous escherichia coli in tumor-bearing mice by nonspecific immunostimulation. | we have previously reported that the lethal toxicity of 5-fluorouracil (5-fu) in specific-pathogen-free mice is due to an indigenous infection with escherichia coli (k. nomoto, t. yokokura, y. yoshikai, et al. can. j. microbiol. 37:244-247, 1991). in the present study, we demonstrate that nonspecific immunostimulation augments host resistance against the lethal toxicity of 5-fu in tumor-bearing mice. intravenous administration of a preparation of heat-killed lactobacillus casei (lc 9018), a nons ... | 1992 | 1458370 |
| fatal lung abscess due to lactobacillus casei ss rhamnosus. | 1992 | 1465766 | |
| prophylactic effect of a lactobacillus casei preparation on the recurrence of superficial bladder cancer. blp study group. | a randomized controlled study was conducted in patients with superficial bladder cancer in order to investigate the safety of an orally administered (3 g/day) lactobacillus preparation, biolactis powder (blp), and its preventive effect on the recurrence after transurethral resection of the bladder tumor (tur-bt). of 58 cases enrolled in the study 23 cases in the blp group and 25 cases in the control group completed the study. there were no significant differences in the patient characteristics f ... | 1992 | 1466089 |
| noncariogenicity of erythritol as a substrate. | erythritol is a sugar alcohol produced by aureobasidium sp. from glucose. it is 75-80% as sweet as sucrose and is also nonhygroscopic. the aim of this study was to evaluate this sugar substitute from a cariological point of view. erythritol was neither utilized as a substrate for the lactic acid production nor for plaque formation of mutans streptococci (serotypes a-h) and certain oral microorganisms. it was not utilized for water-insoluble glucan synthesis or cellular adherence by glucosyltrans ... | 1992 | 1468100 |
| analysis of exopolysaccharide production by lactobacillus casei cg11, isolated from cheese. | exopolysaccharide-producing lactobacillus casei cg11 was isolated from soft, white, homemade cheese. in basal minimal medium, it produces a neutral heteropolysaccharide consisting predominantly of glucose (about 75%) and rhamnose (about 15%). plasmid curing experiments revealed that exopolysaccharide production by strain cg11 is linked to a plasmid approximately 30 kb in size. | 1992 | 1476450 |
| in vitro studies on the growth of shigella sonnei by lactobacillus casei and lact. acidophilus. | the inhibitory effect of lactobacilli on growth of shigella sonnei was studied. the effect was not due to ph alone, as addition of hydrochloric, lactic or acetic acids to culture media did not inhibit the normal growth of the shigellas. the degree of inhibition was measured by disc assay and showed that the inhibitory substance(s) can be extracellular and diffusible, varying the degrees of inhibition depending on the media tested. when broth was inoculated with mixed cultures of lactobacillus an ... | 1992 | 1490909 |
| cloning, sequencing and expression of the gene encoding the cell-envelope-associated proteinase from lactobacillus paracasei subsp. paracasei ncdo 151. | the gene encoding the cell-envelope-associated proteinase of lactobacillus paracasei subsp. paracasei ncdo 151 (formerly lactobacillus casei ncdo 151) was cloned and sequenced. the gene was located on the chromosome and encoded a polypeptide of 1902 amino acids. the proteinase is n-terminally cleaved upon maturation. it shows extensive homology to the lactococcus lactis subsp. cremoris wg2 proteinase. similar to the situation in lactococcus, a maturation gene was found upstream of the proteinase ... | 1992 | 1512565 |
| utilization of organic acids and amino acids by species of the genus bacillus: a useful means in taxonomy. | the type strains of 26 bacillus species were investigated with respect to their capability to utilize 48 organic acids and 20 amino acids by using phenol red indicator plates and an amino acid analyzer, respectively. in addition, strains of bacillus sphaericus were found to utilize many organic acids and amino acids in contrast to carbohydrates which are routinely checked. the results obtained indicated an individual utilization pattern for every species investigated, pointing to a useful taxono ... | 1992 | 1512703 |
| construction and characterization of shuttle plasmids for lactic acid bacteria and escherichia coli. | the chimeric plasmid pbn183 was first constructed in escherichia coli by ligating the bamhi-digested e. coli plasmid pbr322 and a bg/ii-linearized streptococcal plasmid, pnz18. the pbn183 transformed e. coli to apr at a frequency of (8.2 +/- 1.2) x 10(5) colony forming units (cfu)/microgram dna. electrotransformation of streptococcus thermophilus with pbn183 yielded cmr, aps clones at a frequency of (2.6 +/- 0.3) x 10(1) cfu/microgram dna. plasmid screening with pbn183-transformed s. thermophilu ... | 1992 | 1518910 |
| two cases of endocarditis due to lactobacillus species: antimicrobial susceptibility, review, and discussion of therapy. | endocarditis caused by lactobacilli may lead to death or to relapse of infection, despite antimicrobial treatment. we report two cases of lactobacillus endocarditis in individuals with native bicuspid aortic valves who survived without relapse and review the 39 other cases reported in the literature. in only 15 previously reported cases have patients been cured with medical therapy alone. one of our patients, who was infected with lactobacillus acidophilus, was cured by medical therapy alone, an ... | 1992 | 1520759 |
| inhibition of microbial adherence and growth by various glass ionomers in vitro. | this study measured the in vitro inhibition of growth and adherence of five oral bacteria by glass-ionomer materials. disks were prepared from two cavity liners and four restorative class materials, by use of teflon plates with circular wells, five mm wide and two mm deep. the bacterial species tested included: a. viscosus, s. mitis, s. mutans, l. casei, and s. sanguis. growth inhibition studies were performed by the spreading of 0.1 ml of standardized inocula over agar plates produced with sele ... | 1992 | 1521678 |
| isolation and properties of the capnocytophaga ochracea bacteriocin. | a bacteriocin from a subgingival plaque isolate of capnocytophaga ochracea was purified and characterized. it was isolated from cell extract and had a molecular weight of 100,000. streptococcus sanguis, streptococcus mitis, streptococcus mutans and propionibacterium acnes were susceptible to the bacteriocin. | 1992 | 1528638 |
| replacement of the folc gene, encoding folylpolyglutamate synthetase-dihydrofolate synthetase in escherichia coli, with genes mutagenized in vitro. | the folylpolyglutamate synthetase-dihydrofolate synthetase gene (folc) in escherichia coli was deleted from the bacterial chromosome and replaced by a selectable kmr marker. the deletion strain required a complementing gene expressing folylpolyglutamate synthetase encoded on a plasmid for viability, indicating that folc is an essential gene in e. coli. the complementing folc gene was cloned into the vector ppm103 (psc101, temperature sensitive for replication), which segregated spontaneously at ... | 1992 | 1548226 |
| evolutionary relationship of nad(+)-dependent d-lactate dehydrogenase: comparison of primary structure of 2-hydroxy acid dehydrogenases. | a comparison of the primary structures of nad(+)-dependent d-lactate dehydrogenase with l-lactate dehydrogenase and l-malate dehydrogenase failed to show any sequence similarity. however, d-2-hydroxyisocaproate dehydrogenase from lactobacillus casei, glycerate dehydrogenase from cucumber, d-3-phosphoglycerate dehydrogenase and erythronate 4-phosphate dehydrogenase from escherichia coli showed 38%, 24%, 24% and 22% amino acid identity, respectively. the profile analysis of the aligned sequences c ... | 1992 | 1567457 |
| purification and crystallization of lactobacillus casei folylpolyglutamate synthetase expressed in escherichia coli. | folylpolyglutamate synthetase (fpgs) from lactobacillus casei has been crystallized with polyethylene glycol and acetate buffer at ph 5.0. the enzyme was obtained from escherichia coli strain sf4 harboring the l. casei fpgs chromosomal gene on a pembl vector (pgt3-8.1). crystals of the enzyme were obtained which diffract to 2.6 a resolution. the crystals are monoclinic, space group p2(1), with unit cell dimensions of a = 54.07 a, b = 45.83 a, c = 84.37 a and beta = 107.92 degrees. a unit cell co ... | 1992 | 1569575 |
| cloning, sequence, and phenotypic expression of kata, which encodes the catalase of lactobacillus sake lth677. | lactobacillus sake lth677 is a strain, isolated from fermented sausage, which forms a heme-dependent catalase. this rare property is highly desirable in sausage fermentation, as it prevents rancidity and discoloration caused by hydrogen peroxide. a gene bank containing mboi fragments of chromosomal dna from lactobacillus sake lth677 in escherichia coli plasmid pbr328 was constructed. the catalase gene was cloned by heterologous complementation of the kat- phenotype of e. coli um2. the catalase s ... | 1992 | 1575485 |
| multibacterial artificial plaque. a model for studying carious process. | a multibacterial artificial plaque was established in vitro on enamel slabs incubated in mixed culture of streptococcus sanguis, streptococcus mutans (serotype c), streptococcus salivarius, lactobacillus casei and actinomyces viscosus. typical structure same as natural plaque was seen under microscope. the caries-like lesion produced under the plaque was observed in enamel sections. the lesion was similar in appearance to natural ones under optic and scanning electron microscopes. the acids prod ... | 1992 | 1576866 |
| microbiological assay on microtitre plates of folate in serum and red cells. | to develop a simple microbiological assay for serum and red cell folates on 96-well microtitre plates, suitable for use in routine clinical diagnosis. | 1992 | 1577973 |
| antimutagenicity of milk cultured with lactic acid bacteria against n-methyl-n'-nitro-n-nitrosoguanidine. | the antimutagenic effect of cultured milk using 71 strains of lactic acid bacteria belonging to the genus lactobacillus, streptococcus, lactococcus, and bifidobacterium on the mutagenicity of n-methyl-n'-nitro-n-nitrosoguanidine was investigated in vitro using salmonella typhimurium ta 100 as an indicator bacterium. each cultured milk sample displayed its characteristic antimutagenic effect on the mutagenicity of n-methyl-n'-nitro-n-nitrosoguanidine. the milk cultured with lactobacillus acidophi ... | 1992 | 1578035 |
| prevention of indigenous infection of mice with escherichia coli by nonspecific immunostimulation. | we have previously reported that the lethal toxicity of 5-fluorouracil (5-fu) in specific-pathogen-free mice is due to an intestinal infection with indigenous escherichia coli induced by the drug (k. nomoto, t. yokokura, y. yoshikai, m. mitsuyama, and k. nomoto, can j. microbiol. 37:244-247, 1991). in the present study we demonstrate that nonspecific immunostimulation is effective in the protection of mice from the lethal indigenous infection induced by 5-fu. intravenous or subcutaneous injectio ... | 1992 | 1605602 |
| modulation of human neutrophil adherence by oral bacteria. | polymorphonuclear neutrophils (pmns) comprise over 90 per cent of leukocytes in the oral cavity. although these phagocytic cells have primary defence roles in the gingiva, their stimulation by micro-organisms may also cause substantial tissue damage due to the release of lysosomal enzymes and oxygen radicals. adherence of pmns to the endothelium and their subsequent diapedesis and egress to areas of infection are considered early vital events in the inflammatory process. in this study, oral bact ... | 1992 | 1605750 |
| mutation of asparagine 229 to aspartate in thymidylate synthase converts the enzyme to a deoxycytidylate methylase. | the conserved asn 229 of thymidylate synthase (ts) forms a cyclic hydrogen bond network with the 3-nh and 4-o of the nucleotide substrate dump. the asn 229 to asp mutant of lactobacillus casei thymidylate synthase (ts n229d) has been prepared, purified, and investigated. steady-state kinetic parameters of ts n229d show 3.5- and 10-fold increases in the km values of ch2h4folate and dump, respectively, and a 1000-fold decrease in kcat. most important, the asp 229 mutation changes the substrate spe ... | 1992 | 1606134 |
| comparison of contact angles and adhesion to hexadecane of urogenital, dairy, and poultry lactobacilli: effect of serial culture passages. | the aim of this study was to examine the hydrophobicities of 23 urogenital, dairy, poultry, and american type culture collection isolates of lactobacilli and to determine the effect on hydrophobicity of serially passaging the strains in liquid medium. to this end, strains were grown after isolation and identification and then serially passaged up to 20 times. hydrophobicity was assessed through contact angle measurements on lawns of cells by using water, formamide, methylene iodide, 1-bromonapht ... | 1992 | 1622224 |
| protein-mediated adhesion of lactobacillus acidophilus bg2fo4 on human enterocyte and mucus-secreting cell lines in culture. | the adhesion of lactobacillus acidophilus bg2fo4, a human stool isolate, to two human enterocytelike cell lines (caco-2 and ht-29) and to the mucus secreted by a subpopulation of mucus-secreting ht29-mtx cells was investigated. scanning electron microscopy revealed that the bacteria interacted with the well-defined apical microvilli of caco-2 cells without cell damage and with the mucus secreted by the subpopulation of ht29-mtx cells. the adhesion to caco-2 cells did not require calcium and invo ... | 1992 | 1622282 |
| purification of x-prolyl dipeptidyl aminopeptidase from lactobacillus casei subspecies. | prolyl dipeptidylaminopeptidases from two subspecies of lactobacillus casei were purified and biochemically characterized. l. casei ssp. casei ul21 (a debittering strain) and l. casei ssp. rhamnosus ul26 (a non-debittering strain) were the source bacteria for this study. purification of the enzymes from both the sources was effected by a gel filtration step through sephacryl s-300 followed by ion-exchange chromatography through deae sephacel. this rendered an electrophoretically homogeneous enzy ... | 1992 | 1622762 |
| complete replacement set of amino acids at the c-terminus of thymidylate synthase: quantitative structure-activity relationship of mutants of an enzyme. | the c-terminal residue of thymidylate synthase (ts) is highly conserved and has been implicated in cofactor binding, catalysis, and a conformational change. the codon for the c-terminal valine of lactobacillus casei ts has been replaced with those for 19 other amino acids and the amber stop codon. fourteen of the resulting mutant proteins were active by genetic complementation using a thy- strain of escherichia coli, and 18 mutants were active by in vitro assay. only the aspartate and amber muta ... | 1992 | 1627545 |
| thymidylate synthase with a c-terminal deletion catalyzes partial reactions but is unable to catalyze thymidylate formation. | the v316am mutant of lactobacillus casei thymidylate synthase has a single amino acid deletion at the c-terminus which abolishes catalysis of dtmp formation. however, v316am catalyzes two partial reactions which require covalent catalysis: a ch2h4folate-dependent exchange of the 5-hydrogen of dump for protons in water and a thiol-dependent dehalogenation of 5-bromo- and 5-iodo-dump. these reactions proceed with kcat and km values similar to those of the wild-type ts-catalyzed reactions. dump, dt ... | 1992 | 1627546 |
| nuclear magnetic resonance detection of bound water molecules in the active site of lactobacillus casei dihydrofolate reductase in aqueous solution. | proton nuclear magnetic resonance spectroscopy has been used to detect two water molecules bound to residues in the active site of the lactobacillus casei dihydrofolate reductase (dhfr). their presence was detected by measuring nuclear overhauser effects between nh protons in protein residues and protons in the individual bound water molecules in two-dimensional nuclear overhauser effect spectroscopy (noesy), in nuclear overhauser effect spectroscopy in the rotating frame (roesy) and three-dimen ... | 1992 | 1640465 |
| d-alanyl-lipoteichoic acid in lactobacillus casei: secretion of vesicles in response to benzylpenicillin. | vesicles containing lipoteichoic acid (lta) have been isolated from lactobacillus casei atcc 7469 grown in the presence of either benzylpenicillin or d-cycloserine. these cell wall antibiotics enhanced the rate of lta and lipid secretion 6.7 times, whereas chloramphenicol inhibited their release. the formation of these vesicles from peripheral and septal wall regions did not appear to be the result of bacteriolysis. the vesicle composition of lta and lipid was similar to that of the cytoplasmic ... | 1992 | 1645126 |
| hydrogen bonding effects on 31p nmr shielding in the pyrophosphate group of nadph bound to l. casei dihydrofolate reductase. | 1991 | 1657637 | |
| [an electron microscopic study of the interaction of bacterial intestinal microflora and rotavirus virions]. | transmission electron microscopy has revealed the capacity of rotaviruses for adsorption on escherichia coli, klebsiella pneumoniae, proteus mirabilis cells and the absence of such capacity with respect to enterococcus faecalis, lactobacillus casei and edwardsiella tarda. different degrees and a varying character of the adsorption of rotaviruses by the representatives of the opportunistic group of bacteria have been established, which may aggravate the course of rotavirus diarrhea due to the agg ... | 1991 | 1661985 |
| a method for the identification of streptococcus mutans in gingival margin plaque by immunofluorescence. | a method was developed to identify streptococcus mutans in natural dental plaque by indirect immunofluorescence staining, using a high-titred polyclonal antiserum raised against a serotype c strain of s. mutans followed by an fitc conjugate. specificity was determined by staining 45 representative strains of plaque organisms, which demonstrated minimal cross-reactions. in vitro incubation of s. mutans nctc 10449 films with a human serum containing antibodies to s. mutans and the presence of extr ... | 1990 | 1688401 |
| the possible role of probiotics as dietary antimutagen. | possible antimutagenic actions of probiotics--mainly lactic acid bacteria--were examined using in vitro and in vivo test systems. in the ames test with salmonella typhimurium ta1538 beef extract and nitrosated beef extract were used as mutagens. l. casei showed high antimutagenic activity on mutagenicity induced by nitrosated beef extract only without s9 mix, whereas omniflora (a lyophilized preparation of lactobacilli and e. coli) and its cell-free culture broth exhibited antimutagenic action o ... | 1991 | 1708108 |
| immunoadjuvant activity of oral lactobacillus casei: influence of dose on the secretory immune response and protective capacity in intestinal infections. | lactobacilli, often used as effectors of host functions, could play an important role in maintaining human health by controlling other intestinal microorganisms capable of producing harmful effects. using an experimental model, we studied the effect of different oral doses of lactobacillus casei on the secretory iga response and the protective capacity of the microorganism in preventing intestinal infections. the optimization of the protective dose of lb. casei by previous feeding and the use of ... | 1991 | 1722492 |
| distribution of an l-isoaspartyl protein methyltransferase in eubacteria. | a protein carboxyl methyltransferase (ec 2.1.1.77) that recognizes age-damaged proteins for potential repair or degradation reactions has been found in all vertebrate tissues and cells examined to date. this enzyme catalyzes the transfer of methyl groups from s-adenosylmethionine to the carboxyl groups of d-aspartyl or l-isoaspartyl residues that are formed spontaneously from normal l-aspartyl and l-asparaginyl residues. a similar methyltransferase has been found in two bacterial species, escher ... | 1992 | 1729230 |
| 31p-nmr assignment and conformational study of nadph bound to lactobacillus casei dihydrofolate reductase based on two-dimensional 1h-31p-heteronuclear and 1h-detected 1h-31p-shift-correlation experiments. | for any detailed nmr conformational study of a protein-ligand complex it is essential to have specific resonance assignments. we have now assigned the pyrophosphate 31p resonances in spectra of nadph bound to lactobacillus casei dihydrofolate reductase (dhfr) by using a combination of 1h-31p-heteronuclear shift-correlation (hetcor), 1h-31p-heteronuclear multiple-quantum-coherence correlation spectroscopy (hmqc-cosy), 1h-1h cosy, homonuclear hartmann-hahn (hohaha) and noe spectroscopy (noesy) exp ... | 1992 | 1740127 |
| the protective activity of immunostimulants against listeria monocytogenes infection in mice. | the function of peritoneal macrophages induced by intraperitoneal (i.p.) injection of attenuated streptococcus pyogenes (ok-432), bacillus calmette guérin (bcg), protein-bound polysaccharide preparation isolated from coriolus vesicolor (psk) or lactobacillus casei was examined. the pma-triggered respiratory burst (production of o2- and h2o2) of macrophages induced by ok-432, bcg or lac. casei was greater than that of resident or thioglycollate-stimulated macrophages and was similar to that of bc ... | 1992 | 1740781 |
| [study of enamel caries-lesion produced by artificial plaque]. | the authors used the cariogenic bacteria isolated from human dental plaque to produce an artificial plaque which can produce carious lesion in vitro. lesions on human enamel slabs produced by artificial plaque and single bacterium were observed under polarized light microscope and scanning electron microscope. the results showed that the characters of artificial carious lesions are very similar to natural enamel caries. it is very difficult to differentiate them under the microscopes. compared w ... | 1991 | 1748401 |
| purification and substrate specificity of a t4 phage intron-encoded endonuclease. | the t4 phage td intron-encoded endonuclease (i-tev i) cleaves the intron-deleted td gene (td delta i) 23 nucleotides upstream of the intron insertion site on the noncoding strand and 25 nucleotides upstream of this site on the coding strand, to generate a 2-base hydroxyl overhang in the 3' end of each dna strand. i-tev i-157, a truncated form in which slightly more than one third (88 residues) of the endonuclease is deleted, was purified to homogeneity and shown to possess endonuclease activity ... | 1991 | 1762916 |
| in vitro antibacterial effect of chlorhexidine added to glass-ionomer cements. | the aims of the present study were to investigate the antibacterial properties of glass-ionomer cements containing different concentrations of chlorhexidine and the possible release of chlorhexidine from the compound. chlorhexidine gluconate or diacetate was mixed with glass-ionomer cements and tested in vitro against strains of lactobacillus casei and mutans streptococci. a spectrophotometric test was used to monitor the release of chlorhexidine from the mixture. in a broth culture test, the hi ... | 1991 | 1763290 |
| cloning and nucleotide sequence of the lactobacillus casei lactate dehydrogenase gene. | an allosteric l-(+)-lactate dehydrogenase gene of lactobacillus casei atcc 393 was cloned in escherichia coli, and the nucleotide sequence of the gene was determined. the gene was composed of an open reading frame of 981 bp, starting with a gtg codon and ending with a taa codon. the sequences for the promoter and ribosome binding site were identified, and a sequence for a structure resembling a rho-independent transcription terminator was also found. | 1991 | 1768113 |
| sugar, fluoride, ph and microbial homeostasis in dental plaque. | factors that may contribute to the maintenance or breakdown of the oral microflora have been studied in the laboratory using a mixed culture chemostat system. carbohydrate type had relatively little influence of the proportions of individual species at neutral ph. in contrast, when the ph was allowed to fall following carbohydrate metabolism, the stability of the microflora was markedly perturbed. the proportions of streptococcus mutans, lactobacillus casei and veillonella dispar increased and t ... | 1991 | 1775479 |
| shuttle plasmid vectors for lactobacillus casei and escherichia coli with a minus origin. | recombinant plasmids which can be used as shuttle vectors between escherichia coli and the industrially used strains of lactobacillus casei were constructed. they have replication regions closely related to those of pub110 and are likely to replicate by a rolling-circle mechanism via a plus-strand-specific dna intermediate in l. casei. both orientations of pala from the staphylococcal plasmid pc194 and those of the intergenic region from coliphage m13 are identified as active minus origins in l. ... | 1991 | 1781687 |
| the possible involvement of protein synthesis in the injection of pl-1 phage genome into its host, lactobacillus casei. | the process of genome dna injection, after adsorption, by phage pl-1 into host cells of lactobacillus casei was monitored by using the electron microscope. injection of dna was inhibited by the protein-synthesis inhibitors chloramphenicol and erythromycin at concentrations where the colony-forming ability of cells not infected by phage was unaffected. the results suggest that protein synthesis may be involved in some way in the process of genome injection. | 1991 | 1783906 |
| comparison of elisa with activity and ligand-binding methods for the determination of thymidylate synthase concentration. | the determination of enzyme levels in cellular extracts by active site titrations or by catalytic activity measurements is relevant in both science and medicine. however, these techniques assume that enzymes exhibit the same response in crude sample matrices as they do in the purified state. we report here an example of how an enzyme-linked immunosorbent assay (elisa) was used to determine the true enzyme concentration which was compared to the effective enzyme concentration obtained by ligand b ... | 1991 | 1790172 |
| lactobacillus casei-induced polyarthritis in lewis rats: histopathological scoring system for evaluation of anti-rheumatic drugs. | a histopathological scoring system which grades drug effects on cellular infiltration, pannus formation, cartilage degradation and bone resorption in l. casei-induced polyarthritis in rats is described. reference anti-rheumatic and anti-inflammatory agents administered on days 2-60 after induction of arthritis were evaluated for effects on paw swelling weekly and graded histopathologic changes on day 60. this animal model affords a tool to evaluated therapeutic agents on the joint destruction re ... | 1991 | 1793038 |
| lactobacillus cell walls and their arthritis-inducing effects in rats. | 1991 | 1794532 | |
| competitive binding radioassay for the determination of 5-fluorodeoxyuridine and 5-fluorodeoxyuridine-5'-monophosphate levels in plasma and tumor tissue. | a competitive binding radioassay was developed to measure 5-fluoro-2'-deoxyuridine (fudr) as well as 5-fluoro-2'-deoxyuridine monophosphate (fdump), fdump has been measured by a competitive binding radioassay with thymidylate synthase as the binding enzyme (ts assay). fudr was enzymatically converted to fdump by thymidine kinase, and then the converted fdump was measured by the competitive binding assay to determine the concentration of fudr in plasma and tumor tissue. as little as 100 pg/ml of ... | 1991 | 1830300 |
| d-lactate dehydrogenase is a member of the d-isomer-specific 2-hydroxyacid dehydrogenase family. cloning, sequencing, and expression in escherichia coli of the d-lactate dehydrogenase gene of lactobacillus plantarum. | the gene encoding d-lactate dehydrogenase (d-lactate: nad+ oxidoreductase, ec 1.1.1.28) of lactobacillus plantarum has been sequenced, and expressed in escherichia coli cells with an inducible expression plasmid, in which the 5'-noncoding region of the gene was replaced with the tac promoter. comparison of the sequence of d-lactate dehydrogenase with l-lactate dehydrogenases, including the l. plantarum l-lactate dehydrogenase, showed no significant homology. in contrast, the d-lactate dehydrogen ... | 1991 | 1840590 |
| effect of age, amount of inoculum and inoculation medium composition on lactic acid production from glucose by lactobacillus casei subsp. rhamnosus. | effect of composition of the medium used for the inoculum cultivation, of the age and amount of the inoculum was investigated using a 3-l glass fermentor with a working volume of 1 l. the highest productivity of the culture was obtained when using a 20% (v/v) 1-d inoculum grown in the mrs medium. yields of lactic acid were 88-97%, while the l(+)-isomer represented about 80% of the total product. | 1991 | 1841859 |
| mobility of the spin-labeled side chains of some novel antifolate inhibitors in their complexes with dihydrofolate reductase. | four spin-labeled inhibitors of dihydrofolate reductase (dhfr) have been synthesized, each of which has the 2,2,6,6-tetramethyl-1-piperidinyloxy (tempo) reporting group at a different distance from the 2,4-diaminopyrimidine moiety by which the inhibitors are anchored and oriented in the active site. inhibitors in which the tempo group is attached by a short side chain are weakly bound to dhfr from bacteria (streptococcus faecium and lactobacillus casei), to the bovine enzyme and to recombinant h ... | 1991 | 1848814 |
| staphylococcal lactose phosphoenolpyruvate-dependent phosphotransferase system: site-specific mutagenesis on the lace gene gives evidence that a cysteine residue is responsible for phosphorylation. | the lactose-specific phosphocarrier protein enzyme ii of the bacterial phosphoenol-pyruvate-dependent phosphotransferase system of staphylococcus aureus was modified by site-specific mutagenesis on the corresponding lace gene in order to replace the histidine residues 245, 274 and 510 and the cysteine residue 476 of the amino acid sequence with a serine residue. the wild-type and mutant genes were expressed in escherichia coli and the gene products were characterized in different in vitro test s ... | 1991 | 1881874 |
| a comparative trial of lc9018 plus doxorubicin and doxorubicin alone for the treatment of malignant pleural effusion secondary to lung cancer. | the efficacy and safety of intrapleural lc9018 (yakult co. ltd., tokyo, japan) with or without doxorubicin (adriamycin; adria laboratories, columbus, oh) were evaluated in a randomized, controlled trial performed in 95 patients with malignant pleural effusions secondary to lung cancer. seventy-six patients were eligible for the assessment of efficacy. the response rate for treatment with intrapleural doxorubicin plus lc9018 (38 patients) was 73.7%, which was significantly higher than the respons ... | 1991 | 1893348 |
| on the optimization of hydrophobic and hydrophilic substituent interactions of 2,4-diamino-5-(substituted-benzyl)pyrimidines with dihydrofolate reductase. | the inhibition constants (kiapp) were obtained from the action of 68 2,4-diamino-5-(substituted-benzyl)pyrimidines on dihydrofolate reductase from an escherichia coli strain mb 1428. subsequently, these results were used to formulate appropriate quantitative structure-activity relationships (qsar). once again these equations emphasize the paramount importance of steric/dispersion factors in enhancing antibacterial potency. hydrophobicity also plays a role, albeit a minor one. comparisons with th ... | 1991 | 1899453 |
| pteroylpolyglutamates in human milk. | considerable variation exists in reported values for total folate content and the pteroylpolyglutamate (pteglun) content of human milk. we investigated possible methodological sources of this variation. in two laboratories, milk folate content (with and without folate conjugase) was determined microbiologically. no differences in total milk folate or pteglun (n greater than 3) content were found between laboratories. pteglun was found to comprise a significant fraction of total milk folate (28%) ... | 1991 | 1901195 |
| affinity labeling of folate transport proteins with the n-hydroxysuccinimide ester of the gamma-isomer of fluorescein-methotrexate. | fluorescein-methotrexate, a derivative in which the fluorophore is linked via a diaminopentane spacer to either the alpha- or gamma-carboxyl group of the glutamate moiety in the drug [gapski et al. (1975) j. med. chem. 18, 526-528], has been synthesized by an improved procedure and separated by deae-trisacryl chromatography into the alpha- and gamma-isomers (alpha-f-mtx and gamma-f-mtx). each isomer was characterized by mass spectrometry, elemental analysis, absorbance spectrum, tlc, and reverse ... | 1991 | 1902381 |
| production of mutant dihydrofolate reductases of lactobacillus casei for nuclear magnetic resonance spectroscopy. | seven mutations (l4p, w21l, d26e, d26n, r57h, r57k and t63q) affecting residues of dihydrofolate reductase of lactobacillus casei, suspected of being important in substrate, inhibitor, or cofactor binding, were made by gapped-duplex site-directed mutagenesis. expression of the l. casei dhfr gene required the removal of nucleotide sequences flanking the coding region. temperature-inducible expression from the lambda pl promoter of plasmid pplc28 allowed synthesis and subsequent affinity purificat ... | 1991 | 1905259 |
| a human lactobacillus strain (lactobacillus casei sp strain gg) promotes recovery from acute diarrhea in children. | to determine the effect of a human lactobacillus strain (lactobacillus casei sp strain gg, gefilac) on recovery from acute diarrhea (82% rotavirus), 71 well-nourished children between 4 and 45 months of age were studied. after oral rehydration, the patients randomly received either lactobacillus gg-fermented milk product, 125 g (10(10-11) colony-forming units) twice daily (group 1); lactobacillus gg freeze-dried powder, one dose (10(10-11) colony-forming units) twice daily (group 2); or a placeb ... | 1991 | 1905394 |
| inhibition of the growth of streptococcus mutans, streptococcus sobrinus and lactobacillus casei by oral peroxidase systems in human saliva. | streptococcus mutans, strep. sobrinus and lactobacillus casei were grown in glucose-supplemented, sterilized, human whole saliva, adjusted to ph 5, 6 or 7. components of the antibacterial peroxidase system--hypothiocyanous acid (hoscn) and hypothiocyanite ions (oscn-)--were generated by adding exogenous h2o2 to sterilized saliva containing endogenous peroxidases and thiocyanate (scn-) ions. hoscn/oscn- generation was proportional to the amount of h2o2 added, and more hoscn/oscn- was detected in ... | 1991 | 1905532 |
| dihydrofolate reductase: sequential resonance assignments using 2d and 3d nmr and secondary structure determination in solution. | three-dimensional (3d) heteronuclear nmr techniques have been used to make sequential 1h and 15n resonance assignments for most of the residues of lactobacillus casei dihydrofolate reductase (dhfr), a monomeric protein of molecular mass 18,300 da. a uniformly 15n-labeled sample of the protein was prepared and its complex with methotrexate (mtx) studied by 3d 15n/1h nuclear overhauser-heteronuclear multiple quantum coherence (noesy-hmqc), hartmann-hahn-heteronuclear multiple quantum coherence (ho ... | 1991 | 1905571 |
| inhibition of thymidylate synthase by glyceraldehyde 3-phosphate. | 1. a number of common metabolites which had carbonyl and/or phosphate groups were tested for their ability to alter the activity of thymidylate synthase from lactobacillus casei. glyceraldehyde 3-phosphate was found to be an effective inhibitor of thymidylate synthase. 2. glyceraldehyde 3-phosphate reversibly inhibited thymidylate synthase with a k1 of 12-13 microm; the inhibition was competitive with dump and noncompetitive with 5,10-methylenetetrahydrofolate which is consistent with an ordered ... | 1991 | 1907578 |
| lactobacillus casei subspecies casei endocarditis--a case report. | lactobacillus sp., generally considered to be a harmless indigenous bacteria of the mucous membrane, occasionally causes serious infections. lactobacillus endocarditis is a very rare disease, and no case has been reported in korea. gram-positive bacilli were isolated from blood cultures of a 41-year-old man with clinically suspected subacute bacterial endocarditis. the patient had a dental procedure 3 months prior to the infection. the isolate was identified as l. casei subsp. casei based on the ... | 1991 | 1908610 |
| the stability of thiamine and thiamine tetrahydrofurfuryl disulfide added to table wines. | both thiamine hydrochloride and thiamine tetrahydrofurfuryl disulfide were added separately to table wines at concentrations equivalent to 0.3 and 1.5 microgram of free thiamine per kj of caloric energy. the resultant mean increments in thiamine activity, measured by lactobacillus fermenti microbiological assay after 21 months of storage, were in the range 55 to 103% of the added vitamin, indicative of high bioavailability of thiamine from this source. | 1991 | 1919806 |
| impact on catalysis of secondary structural manipulation of the alpha c-helix of escherichia coli dihydrofolate reductase. | the alpha c-helix of escherichia coli dihydrofolate reductase has been converted to its counterpart in lactobacillus casei by a triple mutation in the helix (h45r, w47y, and i50f). these changes result in a 2-fold increase in the steady-state reaction rate (kcat = 26 s-1) that is limited by an increased off rate for the release of tetrahydrofolate (koff = 40 s-1 versus 12 s-1). on the other hand the mutant protein exhibits a 10-fold increase in the km value (6.8 microm) for dihydrofolate and a 1 ... | 1991 | 1993166 |
| synthesis and biological activity of 5,11-methylenetetrahydro-5- deazahomofolic acid. | the synthesis of 5,11-methylene-5-deazatetrahydrohomofolate (5), a stable, semirigid mimic of 5,10-methylenetetrahydrofolate (4) is reported as a potential inhibitor of thymidylate synthases (ts). the key intermediate 3-amino-1-oxo-tetrahydropyrimido[4,5-c] [2,6]naphthyridine (6) was obtained by the regiospecific cyclocondensation of 2,4,6-triaminopyrimidine with ethyl 1-benzyl-3-oxo-4-piperidinecarboxylate followed by halogenation (of the resulting lactam 9) and catalytic hydrogenolysis. select ... | 1991 | 1995884 |
| radioprotection of mice by a single subcutaneous injection of heat-killed lactobacillus casei after irradiation. | treatment of whole-body gamma-irradiated mice with a preparation of lactobacillus casei (lc 9018) immediately after irradiation caused a sustained increase in serum colony-stimulating activity which was followed by an enhanced repopulation of granulocyte-macrophage colony-forming cells in the femoral marrow and spleen. numbers of blood leukocytes, erythrocytes, and platelets were increased earlier in the treated mice than in the controls, and the survival rate was elevated significantly. the rad ... | 1991 | 2000453 |
| a iiiman protein is involved in the transport of glucose, mannose and fructose by oral streptococci. | we show in this article that the transport of glucose, mannose and fructose by the phosphoenolpyruvate: mannose phosphotransferase system of oral streptococci requires the participation of a protein component that we have called iiiman. this protein was purified from streptococcus salivarius by chromatography on deae-cellulose, deae-tsk, hydroxyapatite, and dyematrex green a. the purified protein migrated as a 38,900 molecular weight protein on a sodium dodecyl sulfate polyacrylamide gel. howeve ... | 1990 | 2098704 |
| cloning and expression of the gene encoding lactobacillus casei folylpoly-gamma-glutamate synthetase in escherichia coli and determination of its primary structure. | a genomic library of lactobacillus casei dna containing 10,000 individual clones was constructed in the plasmid puc13. the gene encoding the l. casei folylpolyglutamate synthetase was isolated from the library by complementation of a folc mutant of escherichia coli. the gene was expressed in e. coli from its own promoter and produced amplified folylpolyglutamate synthetase activity with properties identical with those of the purified l. casei enzyme. the absence of dihydrofolate synthetase activ ... | 1990 | 2105929 |
| tetrahydrohomofolate polyglutamates as inhibitors of thymidylate synthase and glycinamide ribonucleotide formyltransferase in lactobacillus casei. | in order to determine the mechanism for the effects of homofolates on growth of lactobacillus casei, polyglutamated derivatives of homofolate (hpteglu), dihydrohomofolate and tetrahydrohomofolate (h4hpteglu) were synthesized and tested as inhibitors of folate-requiring enzymes. the following l. casei enzymes were examined: thymidylate synthase (ts), glycinamide ribonucleotide formyltransferase (garft), aminoimidazolecarboxamide ribonucleotide formyltransferase, serine hydroxymethyltransferase an ... | 1990 | 2106831 |
| role of aspartate 27 of dihydrofolate reductase from escherichia coli in interconversion of active and inactive enzyme conformers and binding of nadph. | the apoenzyme of wild-type (wt) dihydrofolate reductase (dhrf) from escherichia coli exists in two conformational states, et and ew, which differ in affinity for nadph and in kinetic competence. dissociation constants for the binary complex of nadph with the two conformers differ by over 100-fold (kdt = 0.17 microm, kdw = 22 microm). rate constants governing the interconversion of conformers are small (t1/2 for ew----et = 71 s), and since ew is not catalytically competent, this conversion is acc ... | 1990 | 2108144 |
| [penicillin-binding proteins of various strains of lactobacillus]. | sensitivity of different species of lactobacillus i.e. l. casei, l. plantarum, l. acidophillus, l. buchneri, l. jugurti and others to penicillins and cephalosporins of various generations was studied. penicillin binding proteins (pbps) of the lactobacillus species were specified. it was shown that the number of pbps depended on the lactobacillus species. l. casei had the least number of pbps (4) and l. brevis had the highest number of pbps (11). competition of 14c-benzylpenicillin with ampicilli ... | 1990 | 2110806 |
| effect of ph on acid production from sorbitol in washed cell suspensions of oral bacteria. | the acid production from sorbitol and glucose was studied under anaerobic conditions in resting cell suspensions of bacteria from the predominant sorbitol-fermenting human dental plaque flora, belonging to the genera streptococcus, lactobacillus and actinomyces. the acid production activity of the bacterial cells was followed by titration with alkali, at environmental ph 7.0, 6.0 and 5.0 after addition of carbohydrate solution. the metabolic end products formed in the suspensions were analyzed t ... | 1990 | 2111221 |
| pentose synthesis in glucose-grown cells of lactobacillus casei. | the pathway of pentose synthesis in glucose-grown cells of lactobacillus casei was ascertained. glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were present in glucose-grown cells, while transaldolase and transketolase were present only in traces. this suggested that only the oxidative arm of this pathway was operative in glucose-grown cells. on the other hand, in ribose-grown cells, transaldolase was induced with a concomitant suppression of glucose-6-phosphate dehydrogen ... | 1990 | 2111278 |
| modulation of pteroylpolyglutamate concentration and length in response to altered folate nutrition in a comprehensive range of rat tissues. | for a range of rat tissue extracts, the concentrations of total folates and of short-chain pteroylpolyglutamates were assayed by lactobacillus casei with and without conjugase treatment, respectively, and the concentration and chain length of h4pteglnn and 5,10-ch2-h4pteglnn together were assayed after binding to thymidylate synthase and tritiated fluorodeoxyuridylate. for rats fed a nonpurified diet and consuming 26 micrograms of folic acid daily, the respective concentrations of these total fo ... | 1990 | 2111379 |
| [acute lipschütz-chapin vulvar ulcer]. | a 17-year-old female patient is described, who had a sexual intercourse, the only in her life, a year before. hectic temperature has developed in the presence of an exacerbation of chronic decompensated tonsillitis; the general status has essentially deteriorated. a sharply painful ulcer, up to 2 cm in diameter, was seen on the lower third of the involved labium majus; lactobacilli casei were isolated from the discharge from this ulcer. after 2 weeks of antibiotic and immunocorrective therapy a ... | 1990 | 2111619 |
| prevention of gastrointestinal infection using immunobiological methods with milk fermented with lactobacillus casei and lactobacillus acidophilus. | the protective effect of feeding milk fermented with a mixture of lactobacillus casei sp. and lb. acidophilus sp. against salmonella typhimurium infection in mice was compared with that obtained feeding milks fermented with these microorganisms individually. the survival rate obtained after oral infection with sal. typhimurium was 100% in mice pretreated by feeding during 8 d with the mixture of lb. casei and lb. acidophilus fermented milks. similar treatments with the individual milks were inef ... | 1990 | 2111829 |
| nucleotide sequences and genomic constitution of five tryptophan genes of lactobacillus casei. | five trp genes, trpd, trpc, trpf, trpb, and trpa, of lactobacillus casei were cloned by transformation of tryptophan auxotrophic mutants of the respective trp genes in escherichia coli. these trp genes appear to constitute an operon and are located in the above order in a segment of dna of 6,468 base pairs. the entire nucleotide sequence of this dna segment was determined. five contiguous open reading frames in this segment can encode proteins consisting of 341, 260, 199, 406, and 266 amino acid ... | 1990 | 2113923 |
| characterization of the parameters affecting covalent binding stoichiometry in binary and ternary complexes of thymidylate synthase. | covalent binding stoichiometries for both the enzyme:5-fluoro-2'-deoxyuridine 5'-monophosphate (fdump) binary complex and the enzyme:fdump:5,10-methylenetetrahydrofolate (inhibitory ternary) complex at equilibrium were measured by the trichloroacetic acid precipitation assay and shown to be a function of temperature, time, ph, salt concentration, buffer composition and thiol concentration. incubation at 37 degrees c yielded the maximum covalent binding ratio (mol fdump/mol enzyme) for the latter ... | 1990 | 2114176 |
| inhibition of thymidylate synthase by the diastereoisomers of leucovorin. | the clinical formulation of leucovorin (5-cho-fh4) is a mixture of diastereoisomers with markedly different pharmacologic properties. comparatively little information is available concerning the cellular pharmacology of reduced folate stereoisomers, due largely to the difficulty in preparing sufficient quantities of these compounds for in vitro use. recent improvements in hplc technology have now facilitated this process, enabling studies of folate stereochemistry on a larger scale. using purifi ... | 1990 | 2114950 |
| the purification of dihydrofolate reductase from drosophila melanogaster. | dihydrofolate reductase (dhfr) has been purified over 30,000-fold from drosophila adults with a yield of 35%, using a combination of low ph extraction, (nh4)2so4 precipitation, sephadex gel filtration, affi-gel blue affinity chromatography, ion exchange and gel filtration fplc. the drosophila enzyme is a soluble, 17-22 kda monomeric protein displaying the two ph optima characteristic of eukaryotic dhfrs. the sequence of the first 23 amino acids from the amino-terminal end of the protein shows th ... | 1990 | 2116172 |
| antagonistic action of lactic cultures toward spoilage and pathogenic microorganisms in food. | the antibacterial properties of cell-free filtrate from lactic cultures were assessed against 10 bacterial cultures. all the five species of lactic culture examined showed antimicrobial activity against tested bacteria. s. aureus was least sensitive of the tested bacteria, followed by e. coli and s. typhosa. e. aerogenes was the most sensitive one. l. casei had the greatest antimicrobial activity. leu. mesenteroides weakly inhibited the growth of the tested bacteria. in general, inoculum density ... | 1990 | 2116596 |
| [transfer of various markers in lactobacilli during transformation of plasmid dna and joint cultivation]. | a system providing a high frequency genetic transfer of various markers making the reference strain lactobacillus buchneri 1837 resistant to lm, em and fus, able to ferment some carbohydrates and antagonistic against pseudomonas diminuta ccm 2657 was developed. the frequency of the marker transfer during the lactobacilli joint cultivation was 1.5 x 10(-5) = 5.5 x 10(-5) to 1.5 x 10(-4) = 5.5 x 10(-4) which was 3-4 orders of magnitude higher than the marker transfer frequency during transformatio ... | 1990 | 2116781 |
| genetic transformation of lactobacillus casei by electroporation. | lactobacillus casei iam1045 was transformed with a plasmid pam beta 1-1, a tra deleted derivative of pam beta 1, by electroporation. effective transformation was achieved in electroporation buffers of a wide range of ph values, and in all phases of cell growth tested, with highest frequency in the early log phase. polyethylene glycol increased the transformation frequency, whereas divalent cations such as mg2+, ca2+ and mn2+ at 0.25 mm decreased the frequency by 2 to 3 orders. highly efficient t ... | 1990 | 2116914 |
| the 1h-nmr assignments of the aromatic resonances in complexes of lactobacillus casei dihydrofolate reductase and the origins of their chemical shifts. | all the aromatic proton resonances in the 500-mhz nmr spectra of lactobacillus casei dihydrofolate reductase have been assigned for several of its complexes with inhibitors. for the complexes with methotrexate and trimethoprim this was achieved by using a combination of nmr techniques in conjunction with a selectively deuterated protein designed to simplify the spectra such that nuclear overhauser effect (noe) connections could be detected with greater ease and certainty. by correlating these no ... | 1990 | 2118112 |
| measurement of 5-methyltetrahydrofolic acid in man by high-performance liquid chromatography. | 5-methyl-5,6,7,8-tetrahydrofolic (5-methylthf) acid can be measured in human serum and whole blood by fluorescence after deproteinization with perchloric acid and separation by high-performance liquid chromatography (hplc). the technique is sensitive, rapid, and correlates with existing methods for total folates. | 1990 | 2118220 |
| electron microscope studies on the intracellular growth of pl-1 phage of lactobacillus casei. | ultrathin sections of the cells of lactobacillus casei infected with or without pl-1 phages were observed by the rapid-freezing and substitution-fixation method. phage-head-like particles were first observed in the nuclear region. the region was seen more widely dispersed in the cytoplasm than that observed by the conventional chemical fixation method. the features of cells just broken open by the infected phages were observed by the sedimentation method devised by us. the bursting occurred in m ... | 1990 | 2118222 |
| purification and characterization of uridine and thymidine phosphorylase from lactobacillus casei. | uridine and thymidine phosphorylases have been purified to homogeneity from crude extracts of lactobacillus casei. both enzymes had an apparent molecular mass of about 80 kda. uridine phosphorylase consisted of four identical subunits while thymidine phosphorylase was composed of two identical ones. the sequence of 23 amino-acid residues from its n-terminal end was analyzed. uridine phosphorylase had a km of 5.0 x 10(-3) m for uridine and 1.24 x 10(-1) m for phosphate, while thymidine phosphoryl ... | 1990 | 2119230 |
| visualization of folate transport proteins by covalent labeling with fluorescein methotrexate. | fluorescein-methotrexate (f-mtx) has been synthesized by an improved procedure and separated via chromatography on deae-trisacryl into the alpha- and gamma-isomers. purity of each isomer was verified by tlc, hplc, and absorbance spectra. identity of the alpha- and gamma-isomers was established by the following biological criteria: the gamma-isomer inhibited dihydrofolate reductase and was hydrolyzed by carboxypeptidase g2 (at the pteroate-glutamate linkage). the alpha-isomer, conversely, was unr ... | 1990 | 2119551 |
| a novel method of preparing totally alpha-deuterated amino acids for selective incorporation into proteins. application to assignment of 1h resonances of valine residues in dihydrofolate reductase. | the pyridoxal/2h2o exchange reaction of the alpha-ch of amino acids is known to be accompanied by racemisation: thus by using a d-amino acid as the starting material any l-amino acid formed in the reaction will be essentially fully deuterated at its alpha-position. we have used this method to prepare alpha-deuterated l-valine and incorporated this biosynthetically into l. casei dihydrofolate reductase. a comparison of the alpha ch-nh fingerprint regions of cosy spectra of deuterated and normal d ... | 1990 | 2121536 |
| [the antitumor activity of lactobacillus casei--the direct effects of l. casei to human tumor cell lines]. | the effects of somatic components of lactobacillus casei (l. casei) were studied on cell growth in vitro. l. casei was able to suppress the growth of mt-2, mt-4 cells from adult t-cell leukemia, molt-4 cells from acute lymphoblastic leukemia and u-937 cells from promonocytic leukemia. this effect was obviously different from the cytotoxicity of vinbrastin, an anti-cancer drug. flow cytometric experiments employing brdu-anti brdu antibody demonstrated an increase of cells in g1 + g0 phases (pre-d ... | 1990 | 2121856 |
| inhibition of edta of growth of lactobacillus casei in the folate microbiological assay and its reversal by added manganese or iron. | 1990 | 2122927 | |
| influence of aflatoxin b1 on gas production by lactic acid bacteria. | the main characteristic of homofermentative lactic acid bacteria is that they do not produce gas from glucose and other sugars. however, in these experiments lactobacillus casei, lb. plantarum and streptococcus lactis in broth media with glucose, galactose, lactose and sucrose, and aflatoxin b1 produces acid and also a significant amount of gas. in the control media without aflatoxin, these bacteria did not produce gas. the data suggest that lactic acid bacteria, known until now as homofermentat ... | 1990 | 2123930 |
| role of lysine-54 in determining cofactor specificity and binding in human dihydrofolate reductase. | lysine-54 of human dihydrofolate reductase (hdhfr) appears to be involved in the interaction with the 2'-phosphate of nadph and is conserved as a basic residue in other species. studies have suggested that in lactobacillus casei dihydrofolate reductase arg-43, the homologous residue at this position, plays an important role in the binding of nadph and in the differentiation of km values for nadph and nadh. a lys-54 to gln-54 mutant (k54q) of hdhfr has been constructed by oligodeoxynucleotide-dir ... | 1990 | 2124504 |
| characterization of the lactose-specific enzymes of the phosphotransferase system in lactococcus lactis. | the plasmid-encoded lactose genes of the lactococcus lactis phosphotransferase system encoding enzyme iiilac (lacf) and enzyme iilac (lace) have been identified and cloned in escherichia coli and l. lactis. nucleotide sequence and transcription analysis showed that these genes are organized into a lactose-inducible operon with the gene order lacf-lace-lacg-lacx, the latter two genes encoding phospho-beta-galactosidase and a 34-kda protein with an unknown function, respectively. the lac-operon is ... | 1990 | 2125052 |
| molecular cloning and dna sequence of lace, the gene encoding the lactose-specific enzyme ii of the phosphotransferase system of lactobacillus casei. evidence that a cysteine residue is essential for sugar phosphorylation. | the gene coding for the lactose-specific enzyme ii of the lactobacillus casei phosphoenolpyruvate-dependent phosphotransferase system, lace, has been isolated by molecular cloning and expressed in escherichia coli. the dna sequence of the lace gene and the deduced amino acid sequence are presented. the putative translation product comprises a hydrophobic protein of 577 amino acids with a calculated molecular mass of 62,350 da. the deduced polypeptide has a high degree of sequence similarity with ... | 1990 | 2125053 |
| nmr studies of multiple conformations in complexes of lactobacillus casei dihydrofolate reductase with analogues of pyrimethamine. | 1h and 19f nmr signals from bound ligands have been assigned in one- and two-dimensional nmr spectra of complexes of lactobacillus casei dihydrofolate reductase with various pyrimethamine analogues (including pyrimethamine [1, 2,4-diamino-5-(4'-chlorophenyl)-6-ethylpyrimidine], fluoropyrimethamine [2, 2,4-diamino-5-(4'-fluorophenyl)-6-ethylpyrimidine], fluoronitropyrimethamine [3, 2,4-diamino-5-(4'-fluoro-3'-nitrophenyl) -6-ethylpyrimidine], and methylbenzoprim [4, 2,4-diamino-5-[4'- (methylbenz ... | 1990 | 2125479 |