| quartromicin, a complex of novel antiviral antibiotics. i. production, isolation, physico-chemical properties and antiviral activity. | a strain of amycolatopsis orientalis no. q427-8 (atcc 53884) was found to produce a complex of new antiviral antibiotics, quartromicin which consisted of at least six components a1, a2, a3, d1, d2 and d3. structural studies suggested that they are a novel type of molecules unrelated to any known antibiotics. each component of quartromicin exhibited antiviral activity against herpes simplex virus type 1, influenza virus type a and human immunodeficiency virus. | 1992 | 1313409 |
| microbial de-mannosylation and mannosylation of teicoplanin derivatives. | the single components of the teicoplanin complex, glycopeptide antibiotics active against gram-positive bacteria, can be converted in the corresponding de-mannosyl derivatives by cultures of nocardia orientalis nrrl 2450 or streptomyces candidus nrrl 3218. conversely, teicoplanin aglycone and other teicoplanin de-mannosyl derivatives can be converted in the corresponding teicoplanin mannosyl derivatives by cultures of actinoplanes teichomyceticus atcc 31121. the biological transformation yields ... | 1991 | 1838104 |
| purification and hydrolytic action of a chitosanase from nocardia orientalis. | chitosanase from the culture filtrate of nocardia orientalis was purified to apparent homogeneity by precipitation with ammonium sulfate followed by cm-sephadex chromatography, biospecific affinity chromatography on a sepharose cl-4b with immobilized chitotriose and by gel filtration on sephadex g-75. the enzyme specifically acted on chitooligosaccharides and chitosan to yield chitobiose and chitotriose as final products. the mode of action of the chitosanase on chitooligosaccharides and their c ... | 1991 | 1888765 |
| mm 47761 and mm 49721, glycopeptide antibiotics produced by a new strain of amycolatopsis orientalis. isolation, purification and structure determination. | two glycopeptide antibiotics mm 47761 and mm 47921 have been isolated from amycolatopsis orientalis ncib 12608. fermentation conditions for their production, and methods for their isolation are described. the metabolites have been characterised by physio-chemical and biological properties and the structure determined by a combination of chemical degradation, cosy and noe nmr studies. both metabolites showed good antibacterial activity against gram-positive organisms. | 1990 | 2120168 |
| in vitro activity of ly264826, a new glycopeptide antibiotic, against gram-positive bacteria isolated from patients with cancer. | the in vitro activity of ly264826, a novel glycopeptide antibiotic produced by amycolatopsis orientalis, was compared with those of vancomycin, teicoplanin, and oxacillin against 311 gram-positive clinical isolates from patients with cancer, ly264826 had lower mics for 90% of isolates (mic90) than vancomycin for all species tested. it was active against oxacillin-resistant isolates including staphylococcus aureus (mic90, 0.5 micrograms/ml), staphylococcus haemolyticus (mic90, 2.0 micrograms/ml), ... | 1990 | 2149921 |
| phenotypic and genotypic heterogeneity of glycopeptide resistance determinants in gram-positive bacteria. | gram-positive glycopeptide-resistant bacteria isolated in various hospitals in europe and in the united states between 1986 and 1988 were collected. three resistance phenotypes could be distinguished. thirty-one enterococci were highly resistant to vancomycin and teicoplanin. resistance was transferable to other enterococci by conjugation for 16 of the 22 isolates that were tested. homology was detected by hybridization between a probe specific for the vana gene, which encodes an inducible high- ... | 1990 | 2291654 |
| purification and characterization of an exo-beta-d-glucosaminidase, a novel type of enzyme, from nocardia orientalis. | a new enzyme capable of hydrolyzing chitobiose, which is an induced enzyme, was purified to apparent homogeneity from the culture filtrate of nocardia orientalis ifo 12806. biospecific affinity chromatography on chitotriitol-sepharose cl-4b was effective for purification of this enzyme. it is clearly demonstrated that the enzyme is an exo-hydrolase, removing single glucosamine residues from the nonreducing terminal of a sequence of beta-(1----4)-linked glucosamine chain, such as chitosan and chi ... | 1990 | 2351651 |
| uk-69,753, a novel member of the efrotomycin family of antibiotics. ii. structure determination and biological activity. | a novel antibiotic, uk-69,753, has been isolated from a submerged fermentation of amycolatopsis orientalis strain n731-15. uk-69,753 has been assigned the structure 1 using spectroscopic means, primarily by nmr analysis. uk-69,753 is a glycoside of factumycin (a40a), a previously reported member of a small group of antibiotics related to aurodox and efrotomycin. uk-69,753 was shown to have potent activity both in vitro and in vivo against the swine pathogen treponema hyodysenteriae. | 1989 | 2584145 |
| uk-69,753, a novel member of the efrotomycin family of antibiotics. i. taxonomy of the producing organism, fermentation and isolation. | uk-69,753 is a novel antibiotic structurally related to efrotomycin and factumycin, produced by a new strain of amycolatopsis orientalis (atcc 53550). the antibiotic potency in the fermentation broth was monitored by hplc with diode array detection. a six tube counter current distribution was used to purify uk-69,753. | 1989 | 2808132 |
| efficient transformation of amycolatopsis orientalis (nocardia orientalis) protoplasts by streptomyces plasmids. | conditions for efficient transformation of amycolatopsis orientalis (nocardia orientalis) protoplasts by streptomyces plasmid cloning vectors were identified. three streptomycete plasmid origins of replication function in a. orientalis, as do the apramycin resistance gene from escherichia coli, the thiostrepton resistance gene from streptomyces azureus, and the tyrosinase gene from streptomyces antibioticus. a. orientalis appears to express some restriction and modification, because highest tran ... | 1987 | 3571169 |
| a cryptic plasmid from nocardia orientalis nrrl 2452, a vancomycin producer. | a plasmid was found in nocardia orientalis (formerly streptomyces orientalis). physical characterization of the plasmid dna indicates a size of 33.5 kb and a single cleavage site for ecor i. the presence of plasmid, and variation in its copy member, did not directly affect vancomycin resistance or production levels. the plasmid represents the first to be isolated and characterized from a glycopeptide-producing nocardia. | 1986 | 3733518 |
| transglycosylation reaction of a chitinase purified from nocardia orientalis. | chitinase from the culture filtrates of nocardia orientalis ifo 12806 was purified to apparent homogeneity by precipitation with ammonium sulfate followed by successive chromatography on cm-sephadex and bio-gel p-60, and finally by affinity chromatography on a phenyl-sepharose cl-4b column. the enzyme, which is essentially a hydrolase, also catalyzed a transglycosylation reaction on tetra-n-acetyl-chitotetraose (glcnac)4 and penta-n-acetyl-chitopentaose (glcnac)5. the enzyme converted the tetras ... | 1987 | 3814620 |
| [respiration of streptomyces orientalis during different conditions of cultivation]. | | 1971 | 5167172 |
| muraceins--muramyl peptides produced by nocardia orientalis as angiotensin-converting enzyme inhibitors. i. taxonomy, fermentation and biological properties. | three muraceins , a family of muramyl peptides, were isolated from nocardia orientalis as inhibitors of angiotensin-converting enzyme (ace). muracein a, the most potent inhibitor, inhibited ace competitively with a ki of 1.5 microm. liver alcohol dehydrogenase and carboxypeptidase a, two other zinc-containing enzymes, were not inhibited at 150 microm. inhibition of ace could not be reversed by divalent cations. | 1984 | 6327590 |
| muraceins--muramyl peptides produced by nocardia orientalis as angiotensin-converting enzyme inhibitors. ii. isolation and structure determination. | three new muramyl peptides ( muraceins a, b and c) have been isolated from fermentations of nocardia orientalis as inhibitors of angiotensin-converting enzyme (ace). structures 1 and 2, for muraceins a and b respectively, were deduced from their spectroscopic properties. muracein c, 3, was shown to be a muramyl pentapeptide containing n-acetylmuramic acid, alanine, glutamic acid, serine and diaminopimelic acid in a 1:2:1:1:1 ratio based on the 1h nmr integration. | 1984 | 6327591 |
| vancomycin use--an historical review. | in the early 1950s the increase of antibiotic-resistant strains of staphylococcus aureus in hospitalized patients with infection stimulated a screening program to develop an effective new agent. a soil sample found in the jungles of borneo contained a microorganism, streptomyces orientalis, that produced a substance later called vancomycin. vancomycin was shown to have antistaphylococcal activity and to be relatively safe when administered to patients. with the resurgence of staphylococcal infec ... | 1984 | 6394574 |
| [regeneration of nocardia orientalis protoplasts]. | a method for effective regeneration of the protoplasts of n. orientalis, a vancomycin-producing organism into viable cells on a rich organic medium was developed. the dependence of the regeneration on the conditions of the protoplast plating out and the level of the regeneration medium dehydration was studied. the highest positive effect was observed when the protoplasts were suspended in the agarized medium and then plated out on the regeneration medium dehydrated by 2.5 per cent. the frequency ... | 1984 | 6486746 |
| n-demethylvancomycin, a novel antibiotic produced by a strain of nocardia orientalis. taxonomy and fermentation. | a novel vancomycin analog, n-demethylvancomycin, is produced by a soil isolate collected in yucatan, mexico. taxonomic studies indicated this microorganism, designated nrrl 15232, is a strain of nocardia orientalis. unlike some glycopeptide antibiotics, virtually none of the n-demethylvancomycin synthesized remained bound to the cells of the producing culture. antibiotic production was markedly depressed by the addition of orthophosphate to the fermentation medium. enrichment of the medium with ... | 1984 | 6547432 |
| numerical classification of some named strains of nocardia asteroides and related isolates from soil. | one hundred and forty-nine strains of nocardiae, freshly isolated from soil samples obtained from a number of countries with either tropical or temperate climates, and from rubber pipe seals, were compared with appropriate marker cultures in a numerical phenetic study using 156 unit characters. marker strains were chosen to represent the nocardia asteroides complex, other nocardia species and related taxa in an effort both to classify the new soil isolates and, possibly, clarify the structure of ... | 1980 | 7003057 |
| nucleotide sequences of streptomycete 16s ribosomal dna: towards a specific identification system for streptomycetes using pcr. | to facilitate the differential identification of the genus streptomyces, the 16s rrna genes of 17 actinomycetes were sequenced and screened for the existence of streptomycete-specific signatures. the 16s rdna of the streptomyces strains and amycolatopsis orientalis subsp. lurida exhibited 95-100% similarity, while that of the 16s rdna of actinoplanes utahensis showed only 88% similarity to the streptomycete 16s rdnas. potential genus-specific sequences were found in regions located around nucleo ... | 1995 | 7496525 |
| enzymic synthesis of lacto-n-triose ii and its positional analogues. | n-acetylhexosaminidase from nocardia orientalis catalysed the synthesis of lacto-n-triose ii glycoside (beta-d-glcnac-(1-3)-beta-d-gal-(1-4)-beta-d-glc-ome, 3) with its isomers beta-d-glcnac-(1-6)-beta-d-gal-(1-4)-beta-d-glc-ome (4) and beta-d-gal-(1-4)-[beta-d-glcnac-(1-6)]-beta-d-glc-ome (5) through n-acetylglucosaminyl transfer from n,n'-diacetylchitobiose (glcnac2) to methyl beta-lactoside. the enzyme formed the mixture of trisaccharides 3, 4 and 5 in 17% overall yield based on glcnac2, in a ... | 1995 | 8595258 |
| a new esterase for the cleavage of pivalic acid-containing prodrug esters of cephalosporins. | an extracellular esterase from the actinomycetes amycolatopsis orientalis was found by screening. it is capable of splitting the isomeric mixture (k/j) of (i, scheme 1) into 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid, pivalic acid, and acetaldehyde with a high yield. the purified enzyme of 55.4 kd by sds-page shows an n-terminal sequence of vrtcadlvrtydlpgavth. the isoelectric point is 8.9 +/- 0.1. it can be immobilized with good yield to va-epoxy biosynth. besides the above-mentioned re ... | 1996 | 8672280 |
| production of hybrid glycopeptide antibiotics in vitro and in streptomyces toyocaensis. | the glycopeptide antibiotics vancomycin and teicoplanin are currently the last line of defence against some microorganisms that are resistant to many drugs. the emergence of vancomycin-resistant and teicoplanin-resistant enterococci underscores the need for more potent antibiotics. the glycosylation patterns of glycopeptides and chemical modifications of the glycosyl moieties have been shown to greatly influence their antibiotic activity, and certain combinations have resulted in highly active n ... | 1997 | 9115410 |
| d-ala-d-ala ligases from glycopeptide antibiotic-producing organisms are highly homologous to the enterococcal vancomycin-resistance ligases vana and vanb. | the crisis in antibiotic resistance has resulted in an increasing fear of the emergence of untreatable organisms. resistance to the glycopeptide antibiotic vancomycin in the enterococci, and the spread of these pathogens throughout the environment, has shown that this scenario is a matter of fact rather than fiction. the basis for vancomycin resistance is the manufacture of the depsipeptide d-ala-d-lactate, which is incorporated into the peptidoglycan cell wall in place of the vancomycin target ... | 1997 | 9177243 |
| enzymic synthesis of 3'-o- and 6'-o-n-acetylglucosaminyl-n-acetyllactosaminide glycosides catalyzed by beta-n-acetyl-d-hexosaminidase from nocardia orientalis. | beta-n-acetyl-d-hexosaminidase from nocardia orientalis catalyzed the synthesis of beta-d-glcnac-(1 --> 3)-beta-d-gal-(1 --> 4)-beta-d-glcnac-oc6h4no2-p (1) and beta-d-glcnac-(1 --> 6)-beta-d-gal-(1 --> 4)-beta-d-glcnac-oc6h4no2-p (2) with its isomer beta-d-gal-(1 --> 4)-[beta-d-glcnac-(1 --> 6)]-beta-d-glcnac-oc6h4no2-p (3) through n-acetylglucosaminyl transfer from n-,n'-diacetylchitobiose to p-nitrophenyl beta-n-acetyllactosaminide. the enzyme formed a mixture of trisaccharides 1, 2, and 3 in ... | 1997 | 9202195 |
| sequencing and analysis of genes involved in the biosynthesis of a vancomycin group antibiotic. | the emergence of resistance to vancomycin, the drug of choice against methicillin-resistant staphylococcus aureus, in enterococci has increased the need for new antibiotics. as chemical modification of the antibiotic structure is not trivial, we have initiated studies towards enzymatic modification by sequencing the dna coding for the biosynthesis of chloroeremomycin (also known as a82846b and ly264826). | 1998 | 9545426 |
| glycopeptide antibiotic resistance genes in glycopeptide-producing organisms. | the mechanism of high-level resistance to vancomycin in enterococci consists of the synthesis of peptidoglycan terminating in d-alanyl-d-lactate instead of the usual d-alanyl-d-alanine. this alternate cell wall biosynthesis pathway is ensured by the collective actions of three enzymes: vanh, vana, and vanx. the origin of this resistance mechanism is unknown. we have cloned three genes encoding homologs of vanh, vana, and vanx from two organisms which produce glycopeptide antibiotics: the a47934 ... | 1998 | 9736537 |
| ddln from vancomycin-producing amycolatopsis orientalis c329.2 is a vana homologue with d-alanyl-d-lactate ligase activity. | vancomycin-resistant enterococci acquire high-level resistance to glycopeptide antibiotics through the synthesis of peptidoglycan terminating in d-alanyl-d-lactate. a key enzyme in this process is a d-alanyl-d-alanine ligase homologue, vana or vanb, which preferentially catalyzes the synthesis of the depsipeptide d-alanyl-d-lactate. we report the overexpression, purification, and enzymatic characterization of ddln, a vana and vanb homologue encoded by a gene of the vancomycin-producing organism ... | 1998 | 9791137 |
| use of mobility ratios to estimate binding constants of ligands to proteins in affinity capillary electrophoresis. | this work evaluates the use of mobility ratios (m) to estimate binding constants of proteins to ligands using affinity capillary electrophoresis (ace). this concept is demonstrated using two model systems: vancomycin (van) from streptomyces orientalis and carbonic anhydrase b (cab, ec 4.2.1.1). a plot of change in m (deltam) over the concentration of ligand [l] versus deltam yields a more useful representation of the scatchard plot in capillary electrophoresis (ce) than traditional plots of the ... | 1998 | 9792511 |
| enzymatic synthesis of beta-d-gal-(1 --> 3)-[beta-d-glcnac-1 --> 6)]-alpha-d-galnac-oc6h4no2-p as a carbohydrate unit of mucin-type 2 core. | we have established a synthetic method for obtaining beta-d-gal-(1 --> 3)-beta-d-glcnac-(1 --> 6)]-alpha-d-galnac-oc6h4no2-p (1), which is a carbohydrate unit of mucin-type 2 core. a beta-n-acetyl-d-hexosaminidase from nocardia orientalis catalyzed the synthesis of the desired compound 1 with its isomers beta-d-galnac-(1 --> 6)-beta-d-gal-(1 --> 3)-alpha-d-galnac-oc6h4no2-p (2) beta-d-glcnac-(1 --> 3)-beta-d-glc-(1 --> 3)-alpha-d-galnac-oc6h4no2-p (3) through n-acetylglucosaminyl transfer from n ... | 1998 | 9881763 |
| vancomycin production is enhanced in chemostat culture with biomass-recycle. | production of the glycopeptide antibiotic vancomycin by amycolatopsis orientalis atcc 19795 was examined in phosphate-limited chemostat cultures with biomass-recycle, employing an oscillating membrane separator, at a constant dilution rate (d= 0. 14 h-1). experiments made under low agitation conditions (600 rpm) showed that the biomass concentration could be increased 3.9-fold with vancomycin production kinetics very similar to that of chemostat culture without biomass-recycle. the specific prod ... | 1999 | 10099566 |
| use of a partial-filling technique in affinity capillary electrophoresis for determining binding constants of ligands to receptors. | this work evaluates the concept of a partial-filling technique in affinity capillary electrophoresis (ace) using two model systems: vancomycin from streptomyces orientalis and carbonic anhydrase b (cab, ec 4.2.1.1). in this technique the capillary is first partially-filled with ligand followed by a sample of receptor and non-interacting standard and electrophoresed. analysis of the change in the mobility ratio, m, of the receptor, relative to the non-interacting standard, as a function of the co ... | 1999 | 10343401 |
| liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry enantiomeric separation of dl-threo-methylphenidate, (ritalin) using a macrocyclic antibiotic as the chiral selector. | vancomycin, a macrocyclic antibiotic, is an amphoteric glycopeptide produced by streptomyces orientalis which has proven to be a viable chiral selector for high performance liquid chromatograph (hplc) (d. w. armstrong, y. tang, s. chen, y. zhou, c. bagwill and j-r. chen, anal. chem. (1994; 66: 1473). while it is related to other glycopeptide antibiotics, vancomycin has a number of unique structural features, including 18 stereogenic centers, five aromatic rings, and two side chains one of which ... | 1999 | 10510420 |
| enterococcal-type glycopeptide resistance genes in non-enterococcal organisms. | although the emergence of vancomycin-resistant enterococci can be attributed, in part, to the increasing use of vancomycin in clinical practice, and glycopeptide use in animal husbandry, the origins of the enterococcal vancomycin resistance genes are not clear. the vancomycin resistance-associated genes in enterococcus gallinarum, enterococcus casseliflavus/flavescens, lactobacillus spp., leuconostoc spp., pediococcus spp., and erysipelothrix rhusiopathiae, are not the source of the high-level v ... | 2000 | 10731599 |
| estimation of receptor-ligand interactions by the use of a two-marker system in affinity capillary electrophoresis. | the study of receptor-ligand interactions by affinity capillary electrophoresis (ace) requires an accurate form of analysis. here, we examine the use of two noninteracting standards (markers) in the analysis of binding constant data in ace studies. this concept is demonstrated using two model systems: carbonic anhydrase b (cab, ec 4.2.1.1) and arylsulfonamides, and vancomycin (van) from streptomyces orientalis and the dipeptide n-acetyl-d-ala-d-ala. in this procedure a plug of receptor and nonin ... | 2000 | 10790302 |
| the vancomycin biosynthetic pathway is induced in oxygen-limited amycolatopsis orientalis (atcc 19795) cultures that do not produce antibiotic. | vancomycin biosynthetic capacity was stimulated in oxygen-limited bioreactor culture (6.4% dot) of amycolatopsis orientalis, coinciding with a down-regulation of the culture growth and protein synthesis rates. however no vancomycin was detected. atp production was similar in oxygen-limited and oxygen-sufficient cultures (400-150 µmole(atp). g(biomass)(-1)). our findings suggest a critical requirement for oxygen flux through the vancomycin biosynthetic pathway, which is only met under nutrient-li ... | 2000 | 10978772 |
| multiple-step ligand injection affinity capillary electrophoresis for determining binding constants of ligands to receptors. | this work demonstrates the use of multiple-step ligand injection affinity capillary electrophoresis (ace) using two model systems: vancomycin from streptomyces orientalis and carbonic anhydrase b (cab, ec 4.2.1.1). in this technique a sample plug of receptor and non-interacting standards is injected by pressure and electrophoresed in a buffer containing a given concentration of ligand. the sequence is repeated for all concentrations of ligand generating a single electropherogram containing a ser ... | 2000 | 11128217 |
| biosynthesis of l-p-hydroxyphenylglycine, a non-proteinogenic amino acid constituent of peptide antibiotics. | the non-proteinogenic amino acid p-hydroxyphenylglycine is a crucial component of certain peptidic natural products synthesized by a non-ribosomal peptide synthetase mechanism. in particular, for the vancomycin group of antibiotics p-hydroxyphenylglycine plays a structural role in formation of the rigid conformation of the central heptapeptide aglycone in addition to being the site of glycosylation. initial labeling studies suggested tyrosine was a precursor of p-hydroxyphenylglycine but the spe ... | 2000 | 11137816 |
| tandem action of glycosyltransferases in the maturation of vancomycin and teicoplanin aglycones: novel glycopeptides. | the glycopeptides vancomycin and teicoplanin are clinically important antibiotics. the carbohydrate portions of these molecules affect biological activity, and there is great interest in developing efficient strategies to make carbohydrate derivatives. to this end, genes encoding four glycosyltransferases, gtfb, c, d, e, were subcloned from amycolatopsis orientalis strains that produce chloroeremomycin (gtfb, c) or vancomycin (gtfd, e) into escherichia coli. after expression and purification, ea ... | 2001 | 11294642 |
| isolation and characterization of actinomycetes from brazilian tropical soils. | actinomycetes have been isolated from three brazilian tropical soils. the dispersion and differential centrifugation procedure revealed count values 1.5 to 5.0 times greater than those obtained by the conventional dilution plate technique for all soils and media tested. eighteen strains, promising for biotechnological applications, were submitted to chemotaxonomic procedures and numerical taxonomy for identification. two were identified as amycolatopsis orientalis, one as streptomyces misakiensi ... | 2001 | 11297360 |
| screening, overexpression and characterization of an n-acylamino acid racemase from amycolatopsis orientalis subsp. lurida. | thirty-one different actinomycete strains were used in a genetic screening using pcr and southern hybridization methods to detect n-acetylamino acid racemases (aar) in order to obtain enzymes with different properties. cloning and sequencing of a 2.5 kb ecori dna fragment from amycolatopsis orientalis subsp. lurida revealed the coding gene of an n-acetylamino acid racemase, which had identities to the aar gene of amycolatopsis sp. ts-1-60 [tokuyama and hatano (1995) appl microbiol biotechnol 42: ... | 2001 | 11341319 |
| chromosome topology and genome size of selected actinomycetes species. | information about the genome organization of actinomycetes species is restricted to a few genera: corynebacterium, mycobacterium, rhodococcus, saccharopolyspora and streptomyces. streptomyces species and saccharopolyspora erythraea were shown to contain a single linear 8 mb chromosome. in contrast, the corynebacterium, mycobacterium and rhodococcus species studied were demonstrated to possess a smaller (3 mb-6.5 mb) single circular chromosome. to investigate whether linear chromosome topology an ... | 2000 | 11386344 |
| [increase in eremomycin production by regeneration and uv-irradiation of amycolatopsis orientalis subsp. eremomycini protoplasts]. | protoplast regeneration of amycolatopsis orientalis subsp. eremomycini producing eremomycin leads to the change of cultural and morphological properties as well as synthesis of secondary metabolites. formation of plus-variants with enchanced antibiotic production was promoted by uv-irradiation of protoplasts. these plus-variants can be successfully used for repeating protoplasting--uv-irradiation of protoplasts with further increasing of the strain productivity. finally activity of the initial a ... | 2001 | 11548282 |
| on-column ligand synthesis coupled to partial-filling affinity capillary electrophoresis to estimate binding constants of ligands to a receptor. | this paper describes a two-step procedure whereby on-column ligand synthesis and partial-filling affinity capillary electrophoresis (pface) are sequentially coupled to each other to determine the binding constants of 9-fluorenylmethoxy carbonyl (fmoc)-amino acid-d-ala-d-ala species to vancomycin (van) from streptomyces orientalis. in this technique four separate plugs of sample are injected onto the capillary column and electrophoresed. the initial sample plug contains a d-ala-d-ala terminus pep ... | 2001 | 11587342 |
| purification, crystallization and preliminary structural studies of dtdp-4-keto-6-deoxy-glucose-5-epimerase (evad) from amycolatopsis orientalis, the fourth enzyme in the dtdp-l-epivancosamine biosynthetic pathway. | the vancomycin class of antibiotics is regarded as the last line of defence against gram-positive bacteria. the compounds used clinically are very complex organic molecules and are made by fermentation. the biosynthesis of these is complex and fascinating. its study holds out the prospect of utilizing genetic engineering of the enzymes in the pathway in order to produce novel vancomycin analogues. in part, this requires detailed structural insight into substrate specificity as well as the enzyme ... | 2002 | 12077451 |
| crystal structure of oxyb, a cytochrome p450 implicated in an oxidative phenol coupling reaction during vancomycin biosynthesis. | gene-inactivation studies point to the involvement of oxyb in catalyzing the first oxidative phenol coupling reaction during glycopeptide antibiotic biosynthesis. the oxyb gene has been cloned and sequenced from the vancomycin producer amycolatopsis orientalis, and the hemoprotein has been produced in escherichia coli, crystallized, and its structure determined to 1.7-a resolution. oxyb gave uv-visible spectra characteristic of a p450-like hemoprotein in the low spin ferric state. after reductio ... | 2002 | 12207020 |
| optimization of fermentation conditions for production of glycopeptide antibiotic vancomycin by amycolatopsis orientalis. | glycopeptides produced by streptomyces species are the drugs used against beta-lactam drug-resistant staphylococcal infections, and vancomycin is important among them. increased prevalence of resistant strains increased the usage of vancomycin worldwide and also promoted attempts for indigenous production. the optimum process conditions ph, temperature, inoculum size, agitation, and aeration for vancomycin production by amycolatopsis orientalis were evaluated, statistically analyzed, and the res ... | 2002 | 12396140 |
| combinatorial glycosylation of glycopeptide antibiotics. | the glycosyltransferases gtfe and gtfd from the vancomycin producer amycolatopsis orientalis have promiscuous substrate and ndp-sugar specificities. they have been used to generate novel glycopeptide antibiotics containing the heptapeptide scaffolds of vancomycin and teichoplanin. | 2002 | 12498878 |
| partial-filling affinity capillary electrophoresis. | partial-filling affinity capillary electrophoresis (pface) is used to examine the binding interactions between two model biological systems: d-ala-d-ala terminus peptides to the glycopeptide antibiotic vancomycin (van) from streptomyces orientalis, and arylsulfonamides to carbonic anhydrase b (cab, ec 4.2.1.1, bovine erythrocytes). using these two systems, modifications in the pface technique are demonstrated including flow-through pface (ftpface), competitive flow-through pface (cftpface), on-c ... | 2003 | 12830361 |
| crystal structure of oxyc, a cytochrome p450 implicated in an oxidative c-c coupling reaction during vancomycin biosynthesis. | gene inactivation studies point to the involvement of oxyc in catalyzing the last oxidative phenol coupling reaction during glycopeptide antibiotic biosynthesis. presently, the substrate and exact timing of the oxyc reaction are unknown. the substrate might be the bicyclic heptapeptide or a thioester derivative bound to a protein carrier domain. oxyc from the vancomycin producer amycolatopsis orientalis was produced in escherichia coli and crystallized, and its structure was determined to 1.9 a ... | 2003 | 12888556 |
| amycolatopsis decaplanina sp. nov., a novel member of the genus with unusual morphology. | strain dsm 44594t, which produces the glycopeptide antibiotic decaplanin, is a member of the genus amycolatopsis based on 16s rrna gene sequence analysis and chemotaxonomic properties. it is the first member of this genus that is reported to form pseudosporangia, which resemble those of members of the genus kibdelosporangium. phylogenetically, the novel taxon is related to amycolatopsis orientalis, amycolatopsis lurida, amycolatopsis azurea, amycolatopsis japonica and amycolatopsis keratiniphila ... | 2004 | 14742486 |
| reclassification of amycolatopsis orientalis subsp. lurida lechevalier et al. 1986 as amycolatopsis lurida sp. nov., comb. nov. | amycolatopsis orientalis subsp. lurida dsm 43134t differs significantly from the type strain of a. orientalis, a. orientalis subsp. orientalis dsm 40040t, and from other species of the genus in genomic and metabolic properties. its elevation to species status as amycolatopsis lurida sp. nov., comb. nov. is justified. | 2004 | 14742491 |
| affinity capillary electrophoresis to examine receptor-ligand interactions. | afffinity capillary electrophoresis (ace) is a new analytical technique that has been shown to be an efficient and accurate tool in studying biomolecular noncovalent interactions and determining binding and dissociation constants of formed complexes. ace uses as its basis the change in migration time of a receptor upon binding to a ligand found in the electrophoresis buffer. subsequent scatchard analysis using noninteracting markers realizes a binding constant. herein, ace and three modification ... | 2004 | 15163857 |
| antimicrobial resistance gene delivery in animal feeds. | avoparcin, a glycopeptide antimicrobial agent related to vancomycin, has been used extensively as a growth promoter in animal feeds for more than 2 decades, and evidence has shown that such use contributed to the development of vancomycin-resistant enterococci. a cluster that includes three genes, vanh, vana, and vanx, is required for high-level resistance to glycopeptides. in the vancomycin producer amycolatopsis orientalis c329.2, homologs of these genes are present, suggesting an origin for t ... | 2004 | 15200859 |
| site-directed mutagenesis and protein 3d-homology modelling suggest a catalytic mechanism for udp-glucose-dependent betanidin 5-o-glucosyltransferase from dorotheanthus bellidiformis. | in livingstone daisy (dorotheanthus bellidiformis), betanidin 5-o-glucosyltransferase (ugt73a5) is involved in the regiospecific glucosylation of betanidin and various flavonols. based on sequence alignments several amino acid candidates which might be essential for catalysis were identified. the selected amino acids of the functionally expressed protein, suggested to be involved in substrate binding and turnover, were substituted via site-directed mutagenesis. the substitution of two highly con ... | 2004 | 15255862 |
| purification and characterization of a chitinase from amycolatopsis orientalis with n-acetyllactosamine-repeating unit releasing activity. | we report a novel enzyme from the culture filtrate of amycolatopsis orientalis, that endoglycosidically releases an n-acetyllactosamine-repeating unit (galbeta1,4glcnacbeta1,3galbeta1,4glcnac, ln2) from a synthetic chromogenic substrate galbeta1,4glcnacbeta1,3galbeta1,4glcnacbeta-pnp (1). the enzyme activity was purified by 80% saturated ammonium sulfate precipitation followed by gel filtration and affinity chromatography. the enzyme splits 1, galbeta1,4glcnacbeta-pnp (2), glcnacbeta1,3galbeta1, ... | 2005 | 16143301 |
| multiple-injection affinity capillary electrophoresis to estimate binding constants of receptors to ligands. | multiple-injection affinity capillary electrophoresis (miace) is used to determine binding constants (kb) between receptors and ligands using as model systems vancomycin and teicoplanin from streptomyces orientalis and actinoplanes teichomyceticus, respectively, and their binding to d-ala-d-ala peptides and carbonic anhydrase b (cab. ec 4.2.1.1) and the binding of the latter to arylsulfonamides. a sample plug containing a non-interacting standard is first injected followed by multiple plugs of s ... | 2005 | 16189681 |
| two exo-beta-d-glucosaminidases/exochitosanases from actinomycetes define a new subfamily within family 2 of glycoside hydrolases. | a glcnase (exo-beta-d-glucosaminidase) was purified from culture supernatant of amycolatopsis orientalis subsp. orientalis grown in medium with chitosan. the enzyme hydrolysed the terminal glcn (glucosamine) residues in oligomers of glcn with transglycosylation observed at late reaction stages. 1h-nmr spectroscopy revealed that the enzyme is a retaining glycoside hydrolase. the glcnase also behaved as an exochitosanase against high-molecular-mass chitosan with k(m) and kcat values of 0.16 mg/ml ... | 2006 | 16316314 |
| multiple-injection affinity capillary electrophoresis to examine binding constants between glycopeptide antibiotics and peptides. | multiple-injection affinity capillary electrophoresis (miace) was used to determine binding constants (k(b)) between vancomycin, ristocetin, and teicoplanin from streptomyces orientalis, nocardia lurida, and actinoplanes teichomyceticus, respectively, and fluorenylmethoxycarbonyl (fmoc)-(gly, ala, val, and phe)-d-ala-d-ala peptides. in this technique, separate plugs of sample containing non-interacting standards, peptide one, buffer, and peptide two, were injected into the capillary column and e ... | 2006 | 16325833 |
| novel actinomycete isolated from bulking industrial sludge. | a novel actinomycete was the predominant filamentous microorganism in bulking activated sludge in a bench-scale reactor treating coke plant wastewater. the bacterium was isolated and identified as an actinomycete that is biochemically and morphologically similar to amycolatopsis orientalis; however, a lack of dna homology excludes true relatedness. at present, the isolate (nrrl b 16216) cannot be assigned to the recognized taxa of actinomycetes. | 1986 | 16347238 |
| reclassification of amycolatopsis orientalis dsm 43387 as amycolatopsis benzoatilytica sp. nov. | amycolatopsis orientalis dsm 43387, a clinical isolate from submandibular mycetoma tissue, is one of three plasmid-bearing strains of the genus amycolatopsis. it degrades aromatic compounds such as m-hydroxybenzoate, but does not produce any antibiotics, in contrast to amycolatopsis orientalis nbrc 12806t. phylogenetic analysis based on a complete 16s rrna gene sequence placed the strain in the clade of amycolatopsis albidoflavus imsnu 22139t, distant from the clade of a. orientalis nbrc 12806t. ... | 2006 | 16403887 |
| amycolatopsis minnesotensis sp. nov., isolated from a prairie soil. | two actinomycete strains, 32u-2t and 32u-4, were isolated from a prairie soil in minnesota and subjected to characterization by means of polyphasic taxonomy. the 16s rrna gene sequences were determined following pcr amplification and cloning. a phylogenetic analysis, based on comparative analysis of 16s rrna gene sequences, indicated that the organisms consistently formed a well-separated, distinct sub-branch within the radiation of the genus amycolatopsis of the family pseudonocardiaceae. the l ... | 2006 | 16403896 |
| metabolic engineering of the e. coli l-phenylalanine pathway for the production of d-phenylglycine (d-phg). | d-phenylglycine (d-phg) is an important side chain building block for semi-synthetic penicillins and cephalosporins such as ampicillin and cephalexin. to produce d-phg ultimately from glucose, metabolic engineering was applied. starting from phenylpyruvate, which is the direct precursor of l-phenylalanine, an artificial d-phg biosynthesis pathway was created. this three-step route is composed of the enzymes hydroxymandelate synthase (hmas), hydroxymandelate oxidase (hmo), and the stereoinverting ... | 2006 | 16466681 |
| exploration of amycolatopsis diversity in soil using genus-specific primers and novel selective media. | large numbers of actinomycetes provisionally assigned to the genus amycolatopsis were isolated from soil samples using a dilution plate procedure and three novel media designed to be selective for members of this genus. a set of genus-specific oligonucleotide primers developed for the rapid identification of unknown amycolatopsis strains was used to determine whether representative strains taken from the selective isolation plates produced the diagnostic amplification product. the 175 isolates w ... | 2006 | 16466884 |
| production of poly(l-lactide)-degrading enzyme by amycolatopsis orientalis for biological recycling of poly(l-lactide). | efficient production of poly(l-lactide)(pla)-degrading enzyme was achieved by addition of 0.1% (w/v) silk fibroin powder into a liquid culture medium of an actinomycete, amycolatopsis orientalis, without other complex nitrogen sources, such as yeast extract and peptone. scaled-up production of the enzyme in a 5-l jar fermenter showed the possibility of producing this enzyme on an industrial scale at low production cost. the extracellular pla-degrading enzyme showed potent degrading activity, whi ... | 2006 | 16477443 |
| exo-beta-d-glucosaminidase from amycolatopsis orientalis: catalytic residues, sugar recognition specificity, kinetics, and synergism. | catalytic residues and the mode of action of the exo-beta-d-glucosaminidase (glcnase) from amycolatopsis orientalis were investigated using the wild-type and mutated enzymes. mutations were introduced into the putative catalytic residues resulting in five mutated enzymes (d469a, d469e, e541d, e541q, and s468n/d469e) that were successfully produced. the four single mutants were devoid of enzymatic activity, indicating that asp469 and glu541 are essential for catalysis as predicted by sequence ali ... | 2006 | 16877749 |
| cloning and expression of a cytochrome p450 hydroxylase gene from amycolatopsis orientalis: hydroxylation of epothilone b for the production of epothilone f. | degenerate pcr primers were used to amplify cytochrome p450 gene fragments from the high-gc gram-negative bacteria amycolatopsis orientalis, which catalyzes the hydroxylation of epothilone b to produce epothilone f. the amplified fragments were used as hybridization probes to identify and clone two intact cytochrome p450 genes. the expression of one of the cloned genes in a streptomyces lividans transformant resulted in the biotransformation of epothilone b to epothilone f. the conversion of epo ... | 2007 | 16972046 |
| partial-filling affinity capillary electrophoresis techniques to probe the binding of glycopeptide antibiotics to d-ala-d-ala terminus peptides. | this work is an overview of our use of affinity capillary electrophoresis (ace) to estimate binding constants between d-ala-d-ala terminus peptides and the glycopeptides vancomycin (van) from streptomyces orientalis, teicoplanin (teic) from actinoplanes teicomyceticus, and ristocetin a (rist) from nocardia lurida. in these studies, modifications in the ace technique, including partial-filling ace (pface), flow-through pface (ftpface), on-column ligand derivatization ace (ocldace), on-column rece ... | 2006 | 17094294 |
| genomic analyses lead to novel secondary metabolites. part 3. eco-0501, a novel antibacterial of a new class. | genomic analyses of amycolatopsis orientalis atcc 43491 strain, deposited as a vancomycin producer, revealed the presence of genetic loci for the production of at least 10 secondary metabolites other than vancomycin. one of these gene clusters, which contained a type i polyketide synthase, was predicted to direct the synthesis of novel class of compound, a glycosidic polyketide eco-0501 (1). screening of culture extracts for a compound with the predicted physicochemical properties of the product ... | 2006 | 17136886 |
| balance between aerobic and anaerobic metabolites production of amycolatopsis orientalis depending on initial glucose concentration. | the effect of glucose concentration as a carbon source in the range of 5-20 g/l on the fermentative productions of intra-and extra-cellular ethanol, acetate, formate, oxalate, lactate, and pyruvate, as well as pyruvate decarboxylase in a. orientalis were investigated, depending on the incubation period. intra-and extra-cellular pyruvate levels increased with rising glucose concentrations up to 15 and 20 g/l of glucose, respectively. in addition, intra-cellular pyruvate levels reached their maxim ... | 2007 | 17516254 |
| optimization of culture conditions and scale-up to pilot and plant scales for vancomycin production by amycolatopsis orientalis. | this report describes the optimization of culture conditions for vancomycin production by amycolatopsis orientalis kccm-10836p, an identified high-vancomycin-producing strain (us11/712,494). among the conditions tested, ph and the dissolved oxygen tension (dot) were key factors affecting vancomycin production. when the ph and dot were controlled at 7.0 and 20-30%, respectively, a dry-cell weight (dcw) of 62.0 g l(-1) and a vancomycin production of 11.5 g l(-1) were obtained after 120 h of batch ... | 2007 | 17938907 |
| enzymatic synthesis of spacer-linked divalent glycosides carrying n-acetylglucosamine and n-acetyllactosamine: analysis of cross-linking activities with wga. | divalent glycosides carrying n-acetyl-d-glucosamine (glcnac) and n-acetyllactosamine (lacnac) were designed and prepared as glycomimetics. first, hexan-1,6-diyl bis-(2-acetamido-2-deoxy-beta-d-glucopyranoside) (glcnac-hx-glcnac) and 3,6-dioxaoct-1,8-diyl bis-(2-acetamido-2-deoxy-beta-d-glucopyranoside) (glcnac-doo-glcnac) were enzymatically synthesized by transglycosylation of an n,n'n'',n'''-tetraacetylchitotetraose [(glcnac)(4)] donor with a primary diol acceptor, utilizing a chitinolytic enzy ... | 2008 | 17977857 |
| amycolatopsis regifaucium sp. nov., a novel actinomycete that produces kigamicins. | the taxonomic position of seven soil actinomycetes provisionally assigned to the genus amycolatopsis was established in a polyphasic study. the isolates, which had identical 16s rrna gene sequences, had closest similarity to the type strain of amycolatopsis orientalis. a representative isolate, strain gy080t, had chemotaxonomic properties that were typical of the genus amycolatopsis and could be distinguished from the type strain of a. orientalis using dna-dna relatedness data. all of the isolat ... | 2007 | 17978218 |
| two roads diverged: the structure of hydroxymandelate synthase from amycolatopsis orientalis in complex with 4-hydroxymandelate. | the crystal structure of the hydroxymandelate synthase (hms).co2+.hydroxymandelate (hma) complex determined to a resolution of 2.3 a reveals an overall fold that consists of two similar beta-barrel domains, one of which contains the characteristic his/his/acid metal-coordination motif (facial triad) found in the majority of fe2+-dependent oxygenases. the fold of the alpha-carbon backbone closely resembles that of the evolutionarily related enzyme 4-hydroxyphenylpyruvate dioxygenase (hppd) in its ... | 2008 | 18215022 |
| use of voltage gradient partial-filling affinity capillary electrophoresis to estimate binding constants of ligands to receptors. | voltage gradient partial-filling affinity capillary electrophoresis (vgpface) is used to determine binding constants between carbonic anhydrase b (cab, e.c.4.2.1.1) and arylsulfonamides, and vancomycin (van) from streptomyces orientalis and teicoplanin (teic) from actinoplanes teicomyceticus and d-ala-d-ala terminus peptides. two variations of vgpface are described herein. in the first technique, the capillary is partially filled with ligand at increasing concentrations followed by a sample cont ... | 2007 | 18232512 |
| purification and characterization of poly(l-lactic acid)-degrading enzymes from amycolatopsis orientalis ssp. orientalis. | polylactide or poly(l-lactic acid) (pla) is a commercially promising material for use as a renewable and biodegradable plastic. three novel pla-degrading enzymes, named plaase i, ii and iii, were purified to homogeneity from the culture supernatant of an effective pla-degrading bacterium, amycolatopsis orientalis ssp. orientalis. the molecular masses of these three plaases as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 24.0, 19.5 and 18.0 kda, with the ph optima ... | 2008 | 18355279 |
| oligosaccharide hydrolysis by chitosanase enzymes monitored by real-time electrospray ionization-mass spectrometry. | the chitosanase-catalyzed hydrolysis of chitosan oligosaccharides was investigated for the first time by real-time electrospray ionization-mass spectrometry (esi-ms). as chitosan oligosaccharides (glcnn, n=2-6) were hydrolyzed by exochitosanase (exo-beta-glucosaminidase) from amycolatopsis orientalis, the reaction time-courses of substrate, intermediate and products could be monitored simultaneously by direct infusion of the reaction solvent into the mass spectrometer. consequently, the analytic ... | 2008 | 18359118 |
| through-a-chip partial filling affinity capillary electrophoresis for estimating binding constants of ligands to receptors. | in this paper, we describe the development of a microfluidic/capillary electrophoresis (ce) technique employing partial filling affinity capillary electrophoresis (pface) to estimate binding constants of ligands to receptors using as model systems carbonic anhydrase b (cab, ec 4.2.1.1) and vancomycin from streptomyces orientalis. using multilayer soft lithography (msl), a microfluidic device (md) consisting of fluid and control channels is fabricated and fitted with an external capillary column. ... | 2008 | 18371682 |
| on-column ligand/receptor derivatization coupled to affinity capillary electrophoresis. | the coupling of on-column derivatization of small molecules to affinity capillary electrophoresis (ace) has only been realized during the past 5 yr. in this technique, multiple zones of reagent(s) and ligand or receptor are injected into the capillary column. upon electrophoresis, zones of sample overlap, yielding product. continued electrophoresis results in the product overlapping with receptor (or ligand, if the receptor was derivatized), thereby causing a shift in migration time of the compo ... | 2008 | 18392588 |
| nucleotide sequence of plasmid pa387 of amycolatopsis benzoatilytica and construction of a conjugative shuttle vector. | the complete nucleotide sequence of plasmid pa387 of amycolatopsis benzoatilytica dsm 43387 was determined. sequence analysis revealed that pa387 is 30,157 bp long and has a g+c content of 71.74%. to obtain a minimal transferable replicon capable of self-replication, a 2,176 bp fragment of pa387 was cloned, and we demonstrated that this fragment is sufficient for autonomous replication. the replication region of pa387 exhibited no significant homology to any known replication proteins available ... | 2008 | 18506900 |
| vancomycin production in batch and continuous culture. | production of the glycopeptide antibiotic vancomycin by two amycolatopsis orientalis strains was examined in batch shake flask culture in a semidefined medium with peptone as the nitrogen source. different growth and production profiles were observed with the two strains; specific production (y(p/x)) was threefold higher with strain atcc 19795 than with strain ncimb 12945. a defined medium with amino acids as the nitrogen source was developed by use of the plackett-burman statistical screening m ... | 1996 | 18623596 |
| the structural basis of substrate recognition in an exo-beta-d-glucosaminidase involved in chitosan hydrolysis. | family 2 of the glycoside hydrolase classification is one of the largest families. structurally characterized members of this family include enzymes with beta-galactosidase activity (escherichia coli lacz), beta-glucuronidase activity (homo sapiens gusb), and beta-mannosidase activity (bacteroides thetaiotaomicron btman2a). here, we describe the structure of a family 2 glycoside hydrolase, csxa, from amycolatopsis orientalis that has exo-beta-d-glucosaminidase (exo-chitosanase) activity. analysi ... | 2009 | 18976664 |
| partial filling multiple injection affinity capillary electrophoresis (pfmiace) to estimate binding constants of receptors to ligands. | partial filling multiple injection affinity capillary electrophoresis (pfmiace) is used to determine binding constants between vancomycin (van) from streptomyces orientalis, teicoplanin (teic) from actinoplanes teicomyceticus and ristocetin (rist) from nocardia lurida to d-ala-d-ala terminus peptides and carbonic anhydrase b (cab, e.c.4.2.1.1) to arylsulfonamides. two variations of pfmiace are described herein. in the first technique, the capillary is partially filled with ligand at increasing c ... | 2007 | 19071288 |
| engineering enzymes for improved catalytic efficiency: a computational study of site mutagenesis in epothilone-b hydroxylase. | epothilone f, 21-hydroxyl-epothilone b, is an intermediate in the synthesis of bms-310705, an antitumor compound that has been evaluated in phase i clinical trials. a bioconversion process utilizing the gram-positive bacterium amycolatopsis orientalis was used to prepare epothilone f from epothilone b. in order to improve the yield of epothilone f, a mutagenesis program was performed with the goal of engineering the epothilone-b hydroxylase (ebh) enzyme to improve the yield of epothilone f throu ... | 2009 | 19179341 |
| structure and function of the glycopeptide n-methyltransferase mtfa, a tool for the biosynthesis of modified glycopeptide antibiotics. | there is a considerable interest in the modification of existing antibiotics to generate new antimicrobials. glycopeptide antibiotics (gpas) are effective against serious gram-positive bacterial pathogens including methicillin-resistant staphylococcus aureus. however, resistance to these antibiotics is becoming a serious problem requiring new strategies. we show that the amycolatopsis orientalis (s)-adenosyl-l-methionine-dependent methyltransferase mtfa, from the vancomycin-class gpa chloroeremo ... | 2009 | 19389626 |
| development of microfluidic chips for heterogeneous receptor-ligand interaction studies. | a simple microfluidic-based technique to quantitate the binding affinity between the glycopeptide antibiotics teicoplanin from actinoplanes teicomyceticus and vancomycin from streptomyces orientalis and 5-carboxyfluorescein-d-ala-d-ala-d-ala (5-fam-(da)(3)) is described. in this work, (3-aminopropyl)triethoxysilane is used to modify the surfaces of a series of microchannels, and each channel is subsequently exposed to a solution of antibiotic for a few minutes. the antibiotic is retained after w ... | 2009 | 19441833 |
| [the structure of antibiotic eremomycin b]. | a new biologically active component, antibiotic eremomycin b, was isolated from the culture liquid of amycolatopsis orientalis subsp. eremomycini, the producing strain for antibiotic eremomycin. its structure was established by nmr spectroscopy and mass spectrometry. eremomycin b was shown to differ from eremomycin by the presence of an n-carboxymethyl substituent in the disaccharide eremosamine fragment. | 2009 | 19928058 |
| the rate-limiting catalytic steps of hydroxymandelate synthase from amycolatopsis orientalis. | hydroxymandelate synthase (hms) catalyzes the committed step in the formation of p-hydroxyphenylglycine, a recurrent substructure of polycyclic nonribosomal peptide antibiotics such as vancomycin. hms has the same structural fold as and uses the same substrates as 4-hydroxyphenylpyruvate dioxygenase (hppd) (4-hydroxyphenylpyruvate (hpp) and o(2)). moreover, hms catalyzes a very similar dioxygenation reaction to that of hppd, adding the second oxygen atom to the benzylic position, rather than the ... | 2010 | 20112984 |
| genome mining in amycolatopsis balhimycina for ferredoxins capable of supporting cytochrome p450 enzymes involved in glycopeptide antibiotic biosynthesis. | ferredoxins are required to supply electrons to the cytochrome p450 enzymes involved in cross-linking reactions during the biosynthesis of the glycopeptide antibiotics balhimycin and vancomycin. however, the biosynthetic gene clusters for these antibiotics contain no ferredoxin- or ferredoxin reductase-like genes. in a search for potential ferredoxin partners for these p450s, here, we report an in silico analysis of the draft genome sequence of the balhimycin producer amycolatopsis balhimycina, ... | 2010 | 20337711 |
| a biosynthetic pathway for be-7585a, a 2-thiosugar-containing angucycline-type natural product. | sulfur is an essential element found ubiquitously in living systems. however, there exist only a few sulfur-containing sugars in nature and their biosyntheses have not been studied. be-7585a produced by amycolatopsis orientalis subsp. vinearia ba-07585 has a 2-thiosugar and is a member of the angucycline class of compounds. we report herein the results of our initial efforts to study the biosynthesis of be-7585a. spectroscopic analyses verified the structure of be-7585a, which is closely related ... | 2010 | 20443562 |
| intra- and extra-cellular flux distributions of tca and glyoxalate cycle and vancomycin production of amycolatopsis orieantalis grown in different glycerol concentration. | the relationship between tricarboxylic acid (tca) and glyoxalate cycle and the effect of their metabolites levels on the vancomycin production of amycolatopsis orientalis were investigated in different concentration of glycerol (2.5-20 g/l). intracellular glycerol levels increased with respect to increases in glycerol concentrations of the growth medium. extracellular glycerol levels decreased slowly up to 24 h while uptake rates were increased during 36-48 h for 10 and 15 g/l and during 36-60 h ... | 2010 | 21058501 |
| pentose phosphate pathway flux analysis for glycopeptide antibiotic vancomycin production during glucose-limited cultivation of amycolatopsis orientalis. | in vivo pentose phosphate pathway (ppp) enzymes such as glucose-6-phosphate dehydrogenase (g6pdh), 6-phosphogluconate dehydrogenase (6pgdh), and transaldolase (tal) activities as well as atp- and adp-level variations of amycolatopsis orientalis were investigated with respect to glucose concentration and incubation period. g6pdh, 6pgdh, and tal activities of a. orientalis reached maximum levels at 48 hr for all glucose concentrations used, after which the levels began to decline. g6pdh, 6pgdh, an ... | 2011 | 21229467 |
| metabolic engineering of the l-phenylalanine pathway in escherichia coli for the production of s- or r-mandelic acid. | mandelic acid (ma), an important component in pharmaceutical syntheses, is currently produced exclusively via petrochemical processes. growing concerns over the environment and fossil energy costs have inspired a quest to develop alternative routes to ma using renewable resources. herein we report the first direct route to optically pure ma from glucose via genetic modification of the l-phenylalanine pathway in e. coli. | 2011 | 21910908 |