| cloning and sequence analysis of cdna encoding rhizopus niveus lipase. | complementary dna encoding rhizopus niveus lipase (rnl) was isolated from the r. niveus if04759 cdna library using a synthetic oligonucleotide corresponding to the amino acid sequence of the enzyme. a clone, which had an insert of 1.0 kilobase pairs, was found to contain the coding region of the enzyme. the lipase gene was expressed in escherichia coli as a lacz fusion protein. the mature rnl consisted of 297 amino acid residues with a molecular mass of 32 kda. the rnl sequence showed significan ... | 1992 | 1368341 |
| high-level secretion of a rhizopus niveus aspartic proteinase in saccharomyces cerevisiae. | the gene encoding an extracellular rhizopus niveus aspartic proteinase i (rnap-i) was introduced into saccharomyces cerevisiae. the yeast cell carrying a plasmid containing the intact rnap-i gene under the control of the glyceraldehyde 3-phosphate dehydrogenase (gapdh) gene promoter of s. cerevisiae did not synthesize rnap-i at all. on the other hand, when the intron of the rnap-i gene had been removed from the gene in the plasmid, the cell secreted rnap-i with high efficiency. processing of the ... | 1990 | 1368591 |
| transformation of a leu- mutant of rhizopus niveus with the leua gene of mucor circinelloides. | | 1992 | 1368957 |
| lipases from different sources vary widely in dependence of catalytic activity on water activity. | we have measured the rates of esterification in hexane catalysed by suspended immobilised lipases (triacylglycerol acylhydrolase, ec 3.1.1.3), with pre-equilibration to known thermodynamic water activity (a(w)). there were important differences between the enzymes from five different microbes in their retention of activity at low a(w). that from rhizomucor miehei showed over 40% maximal activity at an a(w) of 0.12, and that from rhizopus niveus was also fairly active at low a(w). lipases from ot ... | 1992 | 1643087 |
| expression of rnase rh from rhizopus niveus in yeast and characterization of the secreted proteins. | the full-length cdna encoding rnase rh, which is secreted extracellularly by rhizopus niveus, was isolated and its nucleotide sequence was determined. it was placed under control of the promoter of the glyceraldehyde 3-phosphate dehydrogenase gene of saccharomyces cerevisiae in a high expression vector in yeast. since yeast cells transformed by this plasmid poorly secreted rnase into the medium, the plasmid pye rnap-rh was constructed, in which the signal sequence of rnase rh was replaced by the ... | 1991 | 1655721 |
| isolation, characterization, and primary structure of a base non-specific and adenylic acid preferential ribonuclease with higher specific activity from trichoderma viride. | in order to elucidate the structure-function relationship of rnases belonging to the rnase t2 family (base non-specific and adenylic acid-preferential rnase), an rnase of this family was purified from trichoderma viride (rnase trv) to give three closely adjacent bands with rnase activity on slab-gel electrophoresis in a yield of 20%. the three rnases gave single band with the same mobility on slab-gel electrophoresis after endoglycosidase f digestion. the enzymatic properties including base spec ... | 1991 | 1794979 |
| cloning and nucleotide sequence of the genomic ribonuclease t2 gene (rntb) from aspergillus oryzae. | using synthetic oligonucleotide probes, we have cloned a genomic dna sequence encoding a ribonuclease (rnase) t2 gene (rntb) from aspergillus oryzae on a 4.8 kb hindiii fragment. dna sequence analysis of the rnase t2 revealed the following: (1) the gene is arranged as five exons and four introns; (2) the deduced amino acid sequence contains 239 amino acid residues of the mature enzyme. in addition, there exist 17 amino acid residues thought to be a signal peptide sequence at the n-terminus and 2 ... | 1991 | 1913876 |
| comparison of the properties of glucoamylases from rhizopus niveus and aspergillus niger. | some properties of the glucoamylase from rhizopus niveus have been determined and compared with the comparable properties of the glucoamylase from aspergillus niger. the enzymes from these organisms possess the following common properties: quantitative conversion of starch to glucose, molecular weights in the range 95,500 to 97,500, and glycoprotein structures with many oligosaccharide side chains attached to the protein moieties of the enzymes. differences in the glucoamylases exist in electrop ... | 1990 | 2106901 |
| primary structure of a base non-specific and adenylic acid preferential ribonuclease from aspergillus saitoi. | the complete primary structure of a base non-specific and adenylic acid preferential rnase (rnase m) from aspergillus saitoi was determined. the sequence was determined by analysis of the peptides generated by digestion of heat-denatured rnase m with lysylendopeptidase, and the peptides generated from rcm rnase m by digestion with staphylococcal v8 protease or chemical cleavage with brcn. it consisted of 238 amino acid residues and carbohydrate moiety attached to the 74th asparagine residue. the ... | 1990 | 2229029 |
| binding of isomaltose and maltose to the glucoamylase from aspergillus niger, as studied by fluorescence spectrophotometry and steady-state kinetics. | the binding of maltose, isomaltose, and d-glucono-1,5-lactone to the glucoamylase [e.c.3.2.1.3] from aspergillus niger was monitored by the fluorescence-intensity change (delta f) based on the tryptophan residues of the enzyme, and the binding parameters (kd and delta fmax) were evaluated from the dependence of delta f on the concentration of substrate and analogue. maltose caused the fluorescence-intensity change, but isomaltose did not, although it is hydrolyzed by the enzyme. both substrates ... | 1990 | 2279245 |
| primary structure of an n-linked sugar chain derived from glucoamylase of rhizopus niveus. | the primary structure of the n-linked sugar chain of rhizopus niveus glucoamylase (major component) was investigated. the carbohydrate moiety was released from the polypeptide backbone by flavobacterium sp. endo-beta-n-acetylglucosaminidase digestion. studies using the method of exoglycosidase digestion of the fluorescent pyridylamino derivative, gel-permeation chromatography on bio-gel p-4 and 400-mhz 1h-nmr spectroscopy revealed that the most abundant structure is (man)8-glcnac-ol. | 1989 | 2492439 |
| stereochemical studies of d-glucal hydration by alpha-glucosidases and exo-alpha-glucanases: indications of plastic and conserved phases in catalysis by glycosylases. | alpha-glucosidases from aspergillus niger, pig serum, ungerminated rice, buckwheat, and sugar beet seeds (but not from brewers' yeast or honeybee) were found to catalyze the hydration of d-glucal. each reactive alpha-glucosidase, incubated with d-glucal in d2o, was shown to protonate (deuteriate) this prochiral substrate from above its re face, i.e., from a direction opposite that assumed for protonating alpha-d-glucosidic substrates. at the same time, d-glucal hydration catalyzed by three of th ... | 1988 | 3284583 |
| purification of a base-specific ribonuclease ru from rhizopus niveus. | a base-specific ribonuclease (rnase) ru (ec 3.1.27.5) was isolated and purified from rhizopus niveus in a yield of 17% by the procedures of acetone precipitation, column chromatography on duolite a-2, deae-cellulose, cm-cellulose, and 2'(3')-aminohexyl-5'-ump-agarose. the enzyme was shown to be homogeneous by polyacrylamide disc electrophoresis. the amino- and carboxyl-terminal amino acids of the enzyme were determined to be an arginine and an aspartic acid, respectively. the enzyme has a base s ... | 1980 | 6168347 |
| scope and mechanism of carbohydrase action. stereocomplementary hydrolytic and glucosyl-transferring actions of glucoamylase and glucodextranase with alpha- and beta-d-glucosyl fluoride. | rhizopus niveus glucoamylase and arthrobacter globiformis glucodextranase, which catalyze the hydrolysis of starch and dextrans, respectively, to form d-glucose of inverted (beta) configuration, were found to convert both alpha- and beta-d-glucosyl fluoride to beta-d-glucose and hydrogen fluoride. each enzyme directly hydrolyzes alpha-d-glucosyl fluoride but utilizes th beta-anomer in reactions that require 2 molecules of substrate and yield glucosyl transfer products which are then rapidly hydr ... | 1981 | 6787047 |
| rice aspartic proteinase, oryzasin, expressed during seed ripening and germination, has a gene organization distinct from those of animal and microbial aspartic proteinases. | the gene organization and nucleotide sequence of an aspartic proteinase (ap) of plant origin were first disclosed by cdna and genomic dna cloning of a rice ap (oryzasin). the deduced amino acid sequence of oryzasin 1 was significantly similar to those of other aps (34-85%), with highest similarity (85%) to barley ap (hvap). oryzasin 1, as well as hvap, is distinct from animal and microbial aps in that the plant aps contain a unique 104-amino-acid insertion in the c-terminal region. the oryzasin ... | 1995 | 7556174 |
| cloning of the rhizopus niveus pyr4 gene and its use for the transformation of rhizopus delemar. | we have cloned a pyr4 gene encoding orotidine-5'-monophosphate decarboxylase of the filamentous fungus rhizopus niveus. the pyr4 gene of r. nivens has an open reading frame composed of 265 amino-acid residues and has two putative introns. we have also isolated a pyr4 mutant of rhizopus delemar from 5-fluoroorotic acid-resistant mutants and transformed it with the pyr4 gene of r. niveus as a selectable marker. introduced dna was integrated into the chromosome in a multiple tandem array. the mitot ... | 1995 | 7586035 |
| analysis of the 3-phosphoglycerate kinase 2 promoter in rhizopus niveus. | promoter analysis was performed on the rhizopus niveus 3-phosphoglycerate kinase 2-encoding gene (pgk2), one of the two pgk genes (pgk1 and pgk2) from this filamentous fungus sequenced so far. deletion mutants of the promoter region were fused to the escherichia coli uida gene (which codes for beta-glucuronidase; gus), and introduced into r. niveus to measure the intracellular gus activities of the transformants. deletion of the sequence between nt -174 to -133 (numbers indicate the position fro ... | 1995 | 7828918 |
| cloning and nucleotide sequence of cdna encoding a lipase from fusarium heterosporum. | fusarium heterosporum produces a solvent-tolerant lipase. a 1.3-kbp lipase cdna was isolated from the cdna library by colony hybridization with an oligonucleotide probe corresponding to the n-terminal amino acid sequence. nucleotide sequence analysis showed an open reading frame of 999 bp, and the deduced amino acid sequence contained the n-terminal sequence determined by edman degradation and the consensus pentapeptide (-gly-x-ser-x-gly-), which is conserved in lipase, esterase, and serine prot ... | 1994 | 7852271 |
| cloning and characterization of two 3-phosphoglycerate kinase genes of rhizopus niveus and heterologous gene expression using their promoters. | two 3-phosphoglycerate kinase genes (pgk1 and pgk2) were cloned from rhizopus niveus. it was deduced that both pgk genes have two introns. they have open reading frames of 1,355 bp and 1,356 bp, and code for proteins of 417 and 416 amino acids, respectively. the first introns of both genes are located at similar positions as those of pgk genes from other fungi based on the deduced amino-acid sequences of pgk proteins. the position of their second introns was similar to that of the seventh intron ... | 1994 | 8082204 |
| glycoprotein e2 of classical swine fever virus: expression in insect cells and identification as a ribonuclease. | two regions of amino acids homologous to the ribonuclease catalysis domain of the fungal rnases t2 of aspergillus oryzae and rh of rhizopus niveus and the plant s-glycoproteins of nicotiana alata are perfectly conserved in the amino acid sequence of the envelope glycoprotein e2 of classical swine fever virus (csfv). to analyze the functional significance of these conserved sequences, the gene encoding e2 was inserted into the p10 locus of baculovirus and expressed in insect cells. recombinant vi ... | 1994 | 8178442 |
| molecular characterization of an extracellular acid-resistant lipase produced by rhizopus javanicus. | an extracellular lipase (triacylglycerol acylhydrolase ec 3.1.1.3), produced by the fungus rhizopus javanicus was purified to homogeneity using an expeditious two-step isolation method. the enzyme, with a molecular mass of 36 kda and a specific activity of 9260 microequivalent of fatty acid released per minute and mg under standard conditions, consists of three isoforms with isoelectric points of 7.8, 7.7, and 7.1, respectively. the purified lipase was digested using chemical and enzymatical pro ... | 1993 | 8329142 |
| synthesis of 2-deoxy-glucooligosaccharides through condensation of 2-deoxy-d-glucose by glucoamylase and alpha-glucosidase. | glucoamylases from aspergillus niger and rhizopus niveus catalyzed condensation of 2-deoxy-d-glucose (dglc) to yield deoxy-glucooligosaccharides with polymerization degrees of 2-5. the enzymes also gave a small amount of products from 3-deoxy-d-glucose, but no products from 6-deoxy-d-glucose. a. niger alpha-glucosidase also catalyzed condensation of dglc, while torula and saccharomyces alpha-glucosidases had low activity. alpha-1,4-, 1,6-, and 1,3-linked deoxy-glucobioses were isolated and ident ... | 1995 | 8520115 |
| the crystal structure of ribonuclease rh from rhizopus niveus at 2.0 a resolution. | the three-dimensional structure of ribonuclease rh (rnase rh), a new class of microbial ribonuclease from rhizopus niveus, has been determined at 2.0 a resolution. the overall structure of rnase rh is completely different from those of other previously studied rnases, such as rnase a from bovine pancreas and rnase t1 from aspergillus oryzae. in the structure of rnase rh, two histidine residues (his46 and his109) and one glutamic acid residue (glu105), which were predicted to be critical to the a ... | 1996 | 8551522 |
| cloning and characterization of the rhizopus niveus leu1 gene and its use for homologous transformation. | the rhizopus niveus leul gene was cloned using a 2-kb hindiii fragment of the leua gene of mucor circinelloides as a hybridization probe. the coding region of this gene comprises 1890 bp that encode a putative protein of 630 amino acids. the predicted amino acid sequence is similar to those of other alpha-isopropylmalate isomerases (alpha-ipmis), showing 79.4%, 71.7%, and 60.6% identity with the mucor circinelloides leua, phycomyces blaskesleeanus leu1, and ustilago maydis leu1, respectively. th ... | 1996 | 8901103 |
| the base specificities of tomato ribonuclease (rnase le) and its asp44 mutant enzyme expressed from yeast cells. | rnase le from cultured tomato cells is a member of the rnase t2 family. it is, however, distinguishable from rnase rh from rhizopus niveus, a typical rnase of the rnase t2 family, by its cd spectrum in the 200-250 nm region. in order to reinvestigate the base specificity of rnase le and to study the role of asn44 in rnase le, which is considered to correspond to the base recognition site asp51 of rnase rh, rnase le, and its asp mutant at the 44th position were expressed from yeast cells with the ... | 1997 | 9095548 |
| accumulation of misfolded protein aggregates leads to the formation of russell body-like dilated endoplasmic reticulum in yeast. | rnap-1, an aspartic proteinase from a filamentous fungus rhizopus niveus, is secreted very efficiently in saccharomyces cerevisiae. it is synthesized first as a precursor form with signal sequence and prosequence in its amino-terminus. our previous study indicated that the prosequence of rnap-i had important roles in its correct folding and secretion in yeast, and that a prosequence-deleted derivative of rnap-i, delta pro, was not secreted but was retained and degraded in the yeast endoplasmic r ... | 1997 | 9290205 |
| [structures and functions of ribonucleases]. | 1. in order to understand the differences in ph optima and reaction rates of rnase a towards low molecular weight substrates and polymer substrates, the subsite structure of bovine pancreatic rnase a was studied. the kinetic studies of various sizes of oligouridylic acids showed that the size of the subsite is three nucleotides long. the kinetic studies on the inhibition of pup, x-ray crystallographies of rnase a-apc and ptp complexes, 31p-nmr studies on the binding of rnase a-pap, and ptp showe ... | 1997 | 9357326 |
| cloning of genomic dna of rhizopus niveus lipase and expression in the yeast saccharomyces cerevisiae. | genomic dna encoding lipase i was cloned from rhizopus niveus strain ifo4759. for expression of this gene in s. cerevisiae, dby746 was transformed with yep352plips, which had the cloned lipase gene under the control of a pgk promoter. this strain secreted the lipase at a high level (350 u/ml). the strain nd-12b was produced by a mating of dby746, harboring yep352plips, and na74-3a, and dissection of asci. this new strain secreted the lipase up to 530 u/ml. moreover, the lipase was produced most ... | 1998 | 9972270 |
| high-level expression of rhizopus niveus lipase in the yeast saccharomyces cerevisiae and structural properties of the expressed enzyme. | rhizopus niveus lipase (rnl) has a unique structure consisting of two noncovalently bound polypeptides (a-chain and b-chain). to improve this enzyme's properties by protein engineering, we have developed a new expression system for the production of recombinant lipase in the yeast saccharomyces cerevisiae. for the present study, we developed a more efficient expression system using the strain nd-12b and the multicopy-type plasmid pjdb219. we purified two types of recombinant lipases, each to a s ... | 1999 | 10092492 |
| a single step purification, immobilization, and hyperactivation of lipases via interfacial adsorption on strongly hydrophobic supports | a number of bacterial lipases can be immobilized in a rapid and strong fashion on octyl-agarose gels (e.g., lipases from candida antarctica, pseudomonas fluorescens, rhizomucor miehei, humicola lanuginosa, mucor javanicus, and rhizopus niveus). adsorption rates in absence of ammonium sulfate are higher than in its presence, opposite to the observation for typical hydrophobic adsorption of proteins. at 10 mm phosphate, adsorption of lipases is fairly selective allowing enzyme purification associa ... | 1998 | 10099284 |
| crystal structure of a ribonuclease from the seeds of bitter gourd (momordica charantia) at 1.75 a resolution. | the ribonuclease mc1 (rnase mc1) from seeds of bitter gourd (momordica charantia) consists of 190 amino acid residues with four disulfide bridges and belongs to the rnase t(2) family, including fungal rnases typified by rnase rh from rhizopus niveus and rnase t(2) from aspergillus oryzae. the crystal structure of rnase mc1 has been determined at 1.75 a resolution with an r-factor of 19.7% using the single isomorphous replacement method. rnase mc1 structurally belongs to the (alpha+beta) class of ... | 1999 | 10446375 |
| expression and mutational analysis of amino acid residues involved in catalytic activity in a ribonuclease mc1 from the seeds of bitter gourd. | the ribonuclease mc1 (rnase mc1) from seeds of bitter gourd (momordica charantia) consists of 190 amino acids and belongs to the rnase t2 family, including fungal rnases typified by rnase rh from rhizopus niveus. we expressed rnase mc1 in escherichia coli cells and made use of site-directed mutagenesis to identify essential amino acid residues for catalytic activity. mutations of his34 and his88 to ala completely abolished the enzymatic activity, and considerable decreases in the enzymatic activ ... | 2000 | 10803962 |
| thermal stability of rhizopus niveus lipase expressed in a kex2 mutant yeast. | lipase from rhizopus niveus (rnl) has a complex structure, and recombinant rnl, has even more complex structural properties in the yeast, saccharomyces cerevisiae. these properties are due to the processing and to the size of the glycosylated sugar chain. the processing site was presumed to be that for the proteinase product of the kex2 gene in yeast. we therefore, constructed an expression system in which the kex2 gene was disrupted to produce a non-processed type of lipase with high thermal st ... | 2000 | 10989173 |
| cloning and expression analysis of nhl1, a gene encoding an extracellular lipase from the fungal pea pathogen nectria haematococca mp vi (fusarium solani f. sp. pisi) that is expressed in planta. | the filamentous fungus nectria haematococca (anamorph fusarium solani f. sp. pisi) resides in soil, and attacks pea seedlings in the area of the underground epicotyl and upper tap root, causing foot rot disease. we detected lipase activity during in vitro growth of n. haematococca. subsequently, a lipase gene was cloned and functionally characterised by heterologous expression in saccharomyces cerevisiae. the full-length cdna of 1152 bp was cloned using a 3' race-pcr approach coupled with cdna l ... | 2001 | 11361331 |
| molecular cloning of an extracellular aspartic proteinase from rhizopus microsporus and evidence for its expression during infection. | an extracellular aspartic proteinase (rmap) from rhizopus microsporus var. rhizopodiformis was detected in the culture supernatant of a fungal isolate from a case of rhinocerebral mucormycosis (case ha). the proteinase was purified to near homogeneity by ion exchange and affinity chromatography on pepstatin agarose. based on its n-terminus the rmap gene was cloned and found to code for 388 amino acids. the preproenzyme has an aminoterminal leader sequence of 65 amino acids, whereas the mature en ... | 2002 | 11860014 |
| gas-phase enzymatic esterification on immobilized lipases in mcm-41 molecular sieves. | several lipolytic enzymes were immobilized in the pores of mcm-41 and al-mcm-41 molecular sieves and used as catalysts in the gas-phase esterification of acetic acid with ethanol. the entrapment of enzymes depended on the molecular sieve and the type of enzyme used. the order of enzymatic activity for enzymes entrapped in the pores of mcm-41 and al-mcm-41 in the esterification reaction was of (rhizopus niveus lipases) < fap-15 (rhizopus oryzae lipases) < lex (mucorjavanicus lipases) < ps (pseudo ... | 2002 | 12018317 |
| degradation of aliphatic polyester films by commercially available lipases with special reference to rapid and complete degradation of poly(l-lactide) film by lipase pl derived from alcaligenes sp. | commercial lipases were examined for their degradation efficiency of aliphatic polyester films. in 100 days immersion of polyester films in lipase solutions at 37 degrees c at ph 7.0, lipase asahi derived from chromobacterium viscosum degraded polybutylene succinate-co-adipate (pbsa), poly (e-caprolactone) (pcl) and polybutylene succinate (pbs), and lipase f derived from rhizopus niveus degraded pbsa and pcl during 4-17 days. lipase f-ap15 derived from rhizopus orizae could degrade pbsa in 22 da ... | 2002 | 12449316 |
| roles of o-mannosylation of aberrant proteins in reduction of the load for endoplasmic reticulum chaperones in yeast. | the protein quality control system in the endoplasmic reticulum (er) ensures that only properly folded proteins are deployed throughout the cells. when nonnative proteins accumulate in the er, the unfolded protein response is triggered to limit further accumulation of nonnative proteins and the er is cleared of accumulated nonnative proteins by the er-associated degradation (erad). in the yeast er, aberrant nonnative proteins are mainly directed for the erad, but a distinct fraction of them inst ... | 2004 | 15377669 |
| biochemical and molecular characterization of a lipase produced by rhizopus oryzae. | a novel strain of rhizopus oryzae wpg secretes a noninduced lipase (rolw) in the culture medium; purified rolw is a protein of 29 kda, the 45 n-terminal amino acid residues were sequenced, this sequence is very homologous to rhizopus delemar lipase (rdl), rhizopus niveus lipase (rnl) and r. oryzae lipase (rol29) sequences; the cloning and sequencing of the part of the gene encoding the mature rolw, shows two nucleotides differences with rdl, rnl and rol29 sequences corresponding to the change of ... | 2006 | 16842350 |
| high-affinity iron permease (ftr1) gene sequence-based molecular identification of clinically important zygomycetes. | the clinical importance of zygomycosis, an emerging and frequently fatal mycotic disease, has increased during recent years. this report describes an identification method based on pcr amplification and sequencing of the high-affinity iron permease 1 gene (ftr1). primers and amplification protocols were established and tested for the identification of rhizopus oryzae, rhizopus microsporus var. rhizopodiformis, r. microsporus var. oligosporus, rhizopus schipperae, rhizopus niveus and rhizopus sto ... | 2008 | 18190575 |
| kinetics of formation of maltose and isomaltose through condensation of glucose by glucoamylase. | a kinetic model was devised for the hydrolysis and synthesis of maltose and isomaltose by two glucoamylases from rhizopus niveus and aspergillus niger, and the validity of the model was verified experimentally at 313 k and ph 5.0. for both enzymes, the formations of maltose and isomaltose from glucose were parallel reversible reactions, and glucosyl transfer between maltose and isomaltose was not observed. the enzymes catalyzed rapid hydrolysis and synthesis of maltose. isomaltose was hydrolyzed ... | 1984 | 18551697 |
| kinetics of condensation of glucose into maltose and isomaltose in hydrolysis of starch by glucoamylase. | kinetics of the condensation of glucose into maltose and isomaltose in the hydrolysis of starch by two types of glucoamylase (from aspergillus niger and rhizopus niveus) was studied both experimentally and theoretically. a kinetic model for the hydrolysis of starch by glucoamylase from a. niger was proposed. in this model the reversible hydrolysis of maltose and isomaltose and the kinetic parameters change were taken into consideration. calculated values agreed approximately with the experimenta ... | 1985 | 18553698 |
| water activity dependence of lipases in non-aqueous biocatalysis. | eleven lipases are tested and it was found that lipases can be divided into three types according to water activity dependence. the first type is lipase that has low water activity dependence and works in a low water activity, its performance changes little with the change of water activity. the optimum water activity is 0.19 and newlase f (rhizopus niveus), lipase fap-15 (rhizopus oryzae) belong to this type. the second type is lipase that has medium water activity dependence and its performanc ... | 2009 | 19455434 |
| extraction of starch by dimethyl sulfoxide and quantitation by enzymatic assay. | a method for the rapid, sensitive, and specific determination of starch in plant tissues is described. starch from a variety of plant tissues is solubilized by stirring for 24 h or by sonication for 40 min in dimethyl sulfoxide. dilution of this extract to less than 20% dimethyl sulfoxide permits a nearly complete hydrolysis of the starch in less than 3 h with glucoamylase from rhizopus niveus. quantitation of liberated glucose by a coupled hexokinase and glucose-6-phosphate dehydrogenase method ... | 2011 | 3107426 |
| enzymatic synthesis of aroma acetoin fatty acid esters by immobilized candida antarctica lipase b. | to enzymatically synthesize aroma acetoin fatty acid esters, useful as flavor and fragrance ingredients in foods. | 2015 | 25851952 |
| structure-function relationships of acid ribonucleases: lysosomal, vacuolar, and periplasmic enzymes. | it is surprising that only relatively recently has attention been directed to the characterization of the properties of acid ribonucleases (rnases), leading to some understanding of their biochemistry and their functional roles. the present review summarizes current progress in this field under the following general topics: (1) the wide distribution of acid rnases in organisms from viruses to animals; (2) recent findings concerning their primary and three-dimensional structure; (3) the structure ... | 1999 | 10190580 |
| 'interfacial affinity chromatography' of lipases: separation of different fractions by selective adsorption on supports activated with hydrophobic groups. | lipases contained in commercial samples of lipase extracts from rhizopus niveus (rnl) and candida rugosa (crl) have been selectively adsorbed on hydrophobic supports at very low ionic strength. under these conditions, adsorption of other proteins (including some esterases) is almost negligible. more interestingly, these lipases could be separated in several active fractions as a function of a different rate or a different intensity of adsorption on supports activated with different hydrophobic g ... | 1998 | 9858762 |
| degradation of rhizopus niveus aspartic proteinase-i with mutated prosequences occurs in the endoplasmic reticulum of saccharomyces cerevisiae. | rhizopus niveus aspartic proteinase-i (rnap-i) is secreted by saccharomyces cerevisiae extracellularly (horiuchi, h., ashikari, t., amachi, t., yoshizumi, h., takagi, m., and yano, k. (1990) agric. biol. chem. 54, 1771-1779). the prosequence of rnap-i has the function to promote correct folding of its mature part. deletion (deltapro) and amino acid substitutions (m1) in the prosequence block secretion of rnap-i (fukuda, r., horiuchi, h., ohta, a., and takagi, m. (1994) j. biol. chem. 269, 9556-9 ... | 1996 | 8662920 |
| the prosequence of rhizopus niveus aspartic proteinase-i supports correct folding and secretion of its mature part in saccharomyces cerevisiae. | extracellular rhizopus niveus aspartic proteinase-i (rnap-i) was secreted effectively by saccharomyces cerevisiae when rnap-i with its preprosequence was synthesized in this organism (horiuchi, h., ashikari, t., amachi, t., yoshizumi, h., takagi, m., and yano, k. (1990) agric. biol. chem. 54, 1771-1779). certain deletions (delta pro, delta 1, delta 2), and amino acid substitutions (m1) in the prosequence blocked secretion of rnap-i, although the protease protection assay revealed that even delta ... | 1994 | 8144542 |
| evidence that three histidine residues of a base non-specific and adenylic acid preferential ribonuclease from rhizopus niveus are involved in the catalytic function. | in order to study the structure-function relationship of an rnase t2 family enzyme, rnase rh, from rhizopus niveus, we investigated the roles of three histidine residues by means of site-specific mutagenesis. one of the three histidine residues of rnase rnap rh produced in saccharomyces cerevisiae by recombinant dna technology was substituted to a phenylalanine or alanine residue. a phe or ala mutant enzyme at his46 or his109 showed less than 0.03%, but a mutant enzyme at his104 showed 0.54% of ... | 1992 | 1429502 |
| isolation and sequence analysis of the arbuscular mycorrhizal fungus glomus mosseae (nicol & gerd.) gerdemann & trappe 3-phosphoglycerate kinase (pgk) gene promoter region. | the glomus mosseae 3-phosphoglycerate kinase (gmpgk) gene promoter has been isolated from a phage genomic library and represents one of the few promoter elements to be isolated and analysed from these symbiotic fungi. the analysis revealed the presence of several motifs which are found in the promoter region of other fungal pgk genes. in particular, dna sequences homologous to segments of the s. cerevisiae and rhizopus niveus upstream activating elements (uas). the importance of these uas sequen ... | 2001 | 11696973 |
| activation of the ras-camp signal transduction pathway inhibits the proteasome-independent degradation of misfolded protein aggregates in the endoplasmic reticulum lumen. | many kinds of misfolded secretory proteins are known to be degraded in the endoplasmic reticulum (er). dislocation of misfolded proteins from the er to the cytosol and subsequent degradation by the proteasome have been demonstrated. using the yeast saccharomyces cerevisiae, we have been studying the secretion of a heterologous protein, rhizopus niveus aspartic proteinase-i (rnap-i). previously, we found that the pro sequence of rnap-i is important for the folding and secretion, and that deltapro ... | 2001 | 11526112 |
| kinetic studies of rhizopus oryzae lipase using monomolecular film technique. | rhizopus oryzae lipase (rol) was found to be a true lipase. this enzyme presents the interfacial activation phenomenon. the n-terminal amino acid sequence of rol was compared to those of rhizopus lipases. purified rol possesses the same n-terminal sequence as the mature rhizopus niveus lipase (rnl). this sequence was found in the last 28 amino acids of the propeptide sequence derived from the cdna of rhizopus delemar lipase (rdl). using the baro-stat method, we have measured the hydrolysis rate ... | 2001 | 11506890 |
| unfolded protein response-induced bip/kar2p production protects cell growth against accumulation of misfolded protein aggregates in the yeast endoplasmic reticulum. | overproduction of delta(pro), a mutated secretory proteinase derived from a filamentous fungus rhizopus niveus, results in formation of gross aggregates (delta(pro) aggregates) in the yeast endoplasmic reticulum (er) lumen, activation of the unfolded protein response (upr) and er membrane proliferation. to investigate the roles of the upr against the delta(pro) aggregates, we constructed an ire1-deleted ((delta)ire1) strain. in contrast to wild-type cells, (delta)ire1 cells ceased to grow severa ... | 1999 | 10569245 |
| enzymatic properties of phenylalanine101 mutant enzyme of ribonuclease rh from rhizopus niveus. | to investigate the role of phe101, a component of a base recognition site (b2 site) of a base-nonspecific rnase rh from rhizopus niveus, we prepared several enzymes mutated at this position, f101w, f101l, f101i, f101a, f101q, f101r, and f101k, and their enzymatic activities towards rna, 16 dinucleoside phosphates, and 2', 3'-cyclic pyrimidine nucleotides were measured. enzymatic activity toward rna of f101w, f101l, and f101i were about 7, 20, and 3.8% of the native enzyme, respectively, and thos ... | 2000 | 11129577 |
| improvement of the optimum temperature of lipase activity for rhizopus niveus by random mutagenesis and its structural interpretation. | random mutagenesis was used to improve the optimum temperature for rhizopus niveus lipase (rnl) activity. the lipase gene was mutated using the error-prone pcr technique. one desirable mutant was isolated, and three amino acids were substituted in this mutant (p18h, a36t and e218v). the wild-type and this randomly mutated lipase were both purified and characterized. the specific activity of the mutant lipase was 80% that of the wild-type. the optimum temperature of the mutant lipase was higher b ... | 2001 | 11334664 |
| ribonucleases from t2 family. | ribonucleases are ubiquitous in distribution. ribonucleases that hydrolyse rna to 3' mononucleotides via 2', 3' cyclic nucleotides are classified into three groups, rnase a, rnase t1, and rnase t2 families. apart from salvage of cellular or extracellular rnas, rnases participate in vital cellular functions such as dna replication, transcription and rna processing, splicing and editing, and control of translation by determining the turnover of rna. t2 family rnases have been implicated in nutriti ... | 2002 | 12109772 |
| purification of several proteolytic enzymes by tosyl- and carbobenzoxy-triethylene-tetramine-sepharoses. | tosyl-triethylenetetramine-sepharose (tos-t-sepharose) and carbenzoxytriethylenetetramine-sepharose (z-t-sepharose) were found to be adsorbents utilizable in the purification of several microbial and animal proteases. the former sepharose derivative adsorbed alpha-chymotrypsin, trypsin, subtilisin, thermolysin and neutral subtilopeptidase at neutral ph range, and acid proteases such as pepsin and rhizopus niveus protease at ph 3.5-6.5. alpha-chymotrypsin and trypsin were eluted with 0.1 n acetic ... | 2000 | 14898 |
| hydrolysis of aryl beta-maltotriosides by sweet potato beta-amylase and soybean beta-amylase. | sweet potato beta-amylase [ec 3.2.1.2, alpha 1,4-d-glucan maltohydrolase]-catalyzed hydrolyses of aryl beta-maltotriosides with substituents, no2-, cl-, and br- at the o-, m-, and p-positions in the phenyl ring were studied at ph 4.8 and 25 degrees c. the hydrolyses of a few of the maltotriosides by soybean beta-amylase [ec 3.2.1.2, alpha-1,4-d-glucan maltohydrolase] were also studied at ph 5.4 and 25 degrees c. it was found that the aryl beta-maltotriosides were preferentially hydrolyzed into m ... | 1998 | 147271 |
| exploring the conformational states and rearrangements of yarrowia lipolytica lipase. | we report the 1.7 å resolution crystal structure of the lip2 lipase from yarrowia lipolytica in its closed conformation. the lip2 structure is highly homologous to known structures of the fungal lipase family (thermomyces lanuginosa, rhizopus niveus, and rhizomucor miehei lipases). however, it also presents some unique features that are described and discussed here in detail. structural differences, in particular in the conformation adopted by the so-called lid subdomain, suggest that the openin ... | 2010 | 20923657 |
| crystal and molecular structure of rnase rh, a new class of microbial ribonuclease from rhizopus niveus. | the crystal structure of rnase rh, a new class of microbial ribonuclease from rhizopus niveus, has been determined at 2.5 a resolution by the multiple isomorphous replacement method. the crystal structure was refined by simulated annealing with molecular dynamics. the current crystallographic r-factor is 0.200 in the 10-2.5 a resolution range. the molecular structure which is completely different from the known structures of rnase a and rnase t1 consists of six alpha-helices and seven beta-stran ... | 1992 | 1633875 |
| application of lipase to concentrate the docosahexaenoic acid (dha) fraction of fish oil. | a commercial lipase preparation from rhizopus niveus was used to concentrate the omega-3 fatty acid, docosahexaenoic acid (dha) component in fish oil. the dha content of cod-liver oil was 9.64% (w/w) of total fatty acids. enzymatic digestion conditions were established which produced a dha content in the monoglycerides fraction of 29.17% (w/w) of total fatty acid, triglyceride, and diglyceride components were 5.72, 9.95, and 15316%, respectively. | 1991 | 18600853 |
| role of lys108 in the enzymatic activity of rnase rh from rhizopus niveus. | in order to elucidate on the mechanism of action of rnase rh from rhizopus niveus, we investigated the role of lys108, which is conserved among the rnase t2 family rnases except for two cases. the rnase activities of lys108 mutant rnases, rnase rnap k108r and k108l, are about 33.5 and 3.1% of that of the wild type enzyme, respectively. the relative rates of cleavage of dinucleoside phosphates by these two mutant enzymes were comparable to those with rna as a substrate. the kinetic parameters of ... | 1995 | 7775395 |
| ph profile of kinetic constants of rnase rh from rhizopus niveus and its mutant enzymes towards upu, and possible mechanisms of rnase rh. | in order to elucidate the mechanism of action of rhizopus niveus rnase rh, we investigated the ph profiles of the kinetic parameters of rnase rnap rh, a derivative of rnase rh, and its mutant enzymes, i.e., rnase rnap rh h104f, rnase rnap rh e105q, and rnase rnap rh d51n. based on comparisons of their profiles we concluded that protonation of his104 is indispensable for the enzymatic activity and glu105 accelerates the enzymatic activity, especially at acid ph centered at ph 3.5. based on these ... | 1994 | 7982886 |
| purification, characterization, and crystallization of two types of lipase from rhizopus niveus. | the purification and some properties of two types of lipase (lipase i and lipase ii) from rhizopus niveus are described. the enzymes were purified to homogeneity by column chromatographies on deae-toyopearl (1 pass) and cm-toyopearl (2 passes). lipase i consists of two polypeptide chains [a small peptide with sugar moiety (a-chain) and a large peptide of molecular weight 34,000 (b-chain)]. lipase ii has a molecular weight of 30,000 consisting of a single polypeptide chain. lipase i appeared to b ... | 1994 | 7765029 |
| enzymatic properties of glutamine 32 mutants of rnase rh from rhizopus niveus, a trial to alter the most preferential inter-nucleotidic linkages of rnase rh. | in order to investigate the effects of mutation of gln32, a component of a base recognition site (b2 site) of a base-nonspecific rnase from rhizopus niveus, we prepared several enzymes mutant at this position, q32f, q32l, q32v, q32t, q32d, q32n, and q32e, and their enymatic activities toward rna and 16 dinucleoside phosphates were measured. enzymatic activities of the mutant enzymes towards rna were between 10-125% of the native enzyme. from the rates of hydrolysis of 16 dinucleoside phosphates ... | 2003 | 12723605 |
| enzymatic properties of serine 93 mutants of rnase rh from rhizopus niveus. a trial to alter the base preference of rnase rh. | in order to investigate the effects of mutation of ser93, a component of base recognition site (b2 site) of a base non-specific rnase from rhizopus niveus, we prepared 10 mutant enzymes at this position, s93a, s93v, s93f, s93t, s93g, s93d, s93n, s93e, s93q and s93r, and their enzymatic activities towards rna and 16 dinucleoside phosphates were measured. enzymatic activities of the mutant enzymes towards rna were between 3.5-75% of the native enzyme. from the rates of hydrolysis of 16 dinucleosid ... | 2005 | 16204932 |
| lipase-catalyzed preparation of s-propranolol in presence of hydroxypropyl beta-cyclodextrins. | a simple method for the preparation of s-propranolol catalyzed by a rhizopus niveus lipase in an aqueous medium is described. hydroxypropyl-beta-cyclodextrin was used for the first time to increase the solubility of (r,s)-o-butyryl propranolol thus permitting the reaction to be carried out in water. the formation of an inclusion complex between (r,s)-o-butyryl propranolol and hydroxypropyl-beta-cyclodextrin was studied and a stoichiometry of 1:1 was determined. the influences of the hydroxypropy ... | 2005 | 16310732 |
| [investigation of permolecular structure of lipase from rhizopus niveus]. | it has been shown by classical biophysical and biochemical methods in combination with atomic microscopy that lipase from rhizopus niveus exists in a water solution as a dimer with a molecular weight of 96 kda. the rate of splitting of triglycerides by a dimeric molecules is twice that of monomers. the heat stability of the monomeric form of lipase at temperatures of 20-60 degrees c is significantly higher than that of the native molecule. | 2011 | 21950063 |
| ph-induced molten globule state of rhizopus niveus lipase is more resistant against thermal and chemical denaturation than its native state. | here, we have characterized four ph-dependent states: alkaline state, "b" (ph 9.0), native state, "n" (ph 7.4), acid-induced state, "a" (ph 2.2) and molten globule state, "mg" (ph 1.8) of rhizopus niveus lipase (rnl) by cd, tryptophanyl fluorescence, ans binding, dls, and enzyme activity assay. this "mg" state lacks catalytic activity and tertiary structure but it has native-like significant secondary structure. the "r (h)" of all the four states of rnl obtained from dls study suggests that the ... | 2012 | 22215307 |
| studies on the subsite structure of amylases. i. interaction of glucoamylase with substrate and analogues studied by difference-spectrophotometry. | studies were made on the ultraviolet difference-spectra of glucoamylase from rhizopus niveus [ec 3.2.1.3] specifically produced by the substrate maltose and the inhibitors, glucose, glucono-1: 5-lactone (gluconolactone), methyl beta-d-glucoside, cellubiose, and cyclohexa-, and cyclohepta-amyloses. of these, maltose and gluconolactone produced characteristic difference spectra with a trough near 300 nm. based on studies with a model compound for a tryptophan residue, ac-trp, this trough was attri ... | 1975 | 1150637 |
| immobilization of lipase on poly(n-vinyl pyrrolidone). | immobilization of lipase from rhizopus niveus on poly(n-vinyl pyrrolidone) was carried out and optimal conditions for manifestation of catalytic activity of this enzyme were determined. kinetic aspects of substrate hydrolysis by free and immobilized lipase were studied. | 2011 | 22448354 |
| the surfactant-induced conformational and activity alterations in rhizopus niveus lipase. | in this study, we have reported the effect of nonionic, anionic, cationic, and zwitterionic detergents on the enzymatic activity and structural stability of rhizopus niveus lipase. secondary structural changes were monitored by far-uv cd which shows that surfactant induces helicity in the rhizopus niveus lipase protein which was maximum in case of ctab followed by sds, chaps, and brij-35. similarly, tertiary structural changes were monitored by tryptophan fluorescence. we also carried out enzyme ... | 2015 | 25424356 |
| transition state structures for the hydrolysis of alpha-d-glucopyranosyl fluoride by retaining and inverting reactions of glycosylases. | secondary tritium and primary 14c kinetic isotope effects were measured for the hydrolysis of alpha-d-glucopyranosyl fluoride catalyzed by sugar beet seed alpha-d-glucosidase, forming alpha-d-glucose, and by rhizopus niveus glucoamylase forming beta-d-glucose. the data provided a novel opportunity to model and directly compare the transition state structures for the hydrolysis of a substrate promoted with retention or inversion of configuration according to the enzyme catalyst. the isotope effec ... | 1994 | 7798231 |
| enhanced production of industrial enzymes in mucoromycotina fungi during solid-state fermentation of agricultural wastes/by-products. | cellulolytic, lipolytic and proteolytic enzyme production of zygomycetes mucor corticolus, rhizomucor miehei, gilbertella persicaria and rhizopus niveus were investigated using agro-industrial wastes as substrates. solid-state cultures were carried out on untreated corn residues (stalk and leaf) as single substrate (ssf1) or corn residues and wheat bran in mixed fermentation (ssf2). rapid production of endoglucanase (cmcase) was observed with maximal activity reaching after about 48-h fermentati ... | 2015 | 26344030 |
| preliminary investigation of crystals of lipase i from rhizopus niveus. | lipase i from rhizopus niveus consists of two polypeptide chains bound non-covalently. lipase i has been crystallized in a form suitable for x-ray diffraction analysis using the hanging drop method of vapour diffusion at 20 degrees c. the crystals grew at ph 6.0 to 7.0 using 14 to 16% polyethylene glycol 8000 as the precipitant. the crystals are tetragonal with space group p4(1) (or p4(3)) and cell dimensions of a = b = 83.7 a, c = 137.9 a. there are two protein molecules in the asymmetric unit. ... | 1993 | 8433372 |
| role of asp51 and glu105 in the enzymatic activity of a ribonuclease from rhizopus niveus. | the active site of a base non-specific rnase from rhizopus niveus (rnase rh), consists of three histidine residues and one carboxyl group [ohgi, k. et al. (1992) j. biochem. 111, 132-138]. in order to identify this acidic amino acid residue, we chose asp51 and glu105 as candidates based on a comparison of the primary structures of four fungal rnases and self-incompatibility factors of nicotiana alata which belong to the rnase t2 family. we substituted these amino acid residues with other amino a ... | 1993 | 8096846 |
| hydrolases in supercritical co2 and their use in a high-pressure membrane reactor. | the thermal stability and activity of enzymes in supercritical carbon dioxide (sc co(2)) and near-critical propane were studied at a pressure of 300 bar in the temperature range 20-90 degrees c. proteinase from carica papaya was incubated in microaqueous sc co(2) at atmospheric pressure in a nonaqueous system. lipase stability in an aqueous medium at atmospheric pressure and in sc co(2) as well as near-critical propane at 100 bar and 40 degrees c was studied. in order to investigate the impact o ... | 2003 | 14505171 |
| enzymatic activities of several k108 mutants of ribonuclease (rnase) rh isolated from rhizopus niveus. | we previously investigated the role of the lys108 residue of ribonuclease (rnase) rh from rhizopus niveus, and suggested that lys108 probably acts to stabilize the pentacovalent intermediate, and that an arg residue could replace the role of lys108. in rnase le2 from lentinus edodes, a homologous enzyme of rnase rh, lys108 is replaced by thr. in this paper, the enzymatic properties of a k108t mutant and its analogous enzyme, k108s, were investigated to determine the effect of thr and its analog, ... | 1996 | 8874821 |
| synthesis of methyl 5'-thio-α-isomaltoside via an acyclic monothioacetal and its behavior toward glucoamylase. | methyl 5'-thio-α-isomaltoside (1), which contains the ring-sulfur analogue of the nonreducing glucoside of isomaltose, was synthesized from gentiobiose through a novel ring opening-recyclization approach. the nonreducing glucoside of per-o-benzylated phenyl 1-thio-β-gentiobioside underwent o-5'-c-1' bond cleavage with dimethyl-boron bromide and thiolacetic acid to give the acyclic monothioacetal 4 with the 1-thioglucopyranoside at the reducing end intact. the ho-5' group in 4 was inverted by a s ... | 1996 | 29178223 |
| enzymatic properties of mutant forms of rnase rh from rhizopus niveus as to asp51. | in order to determine the role of asp51 of rnase rh from rhizopus niveus, enzymes with mutations at the 51st position, d51n, d51e, d51q, d51s, d51t, d51a, and d51k, were prepared, and their enzymatic properties were investigated as to specific activity and base specificity. all the mutant enzymes showed relatively high activity toward poly i and poly c, and markedly reduced activity toward poly a and poly u. in particular, the enzymatic activities toward poly i of d51t and d51s were higher than ... | 1996 | 8830052 |
| enzymatic properties of mutant enzymes at trp49 and tyr57 of rnase rh from rhizopus niveus. | in order to establish the role of tyr57 and trp49 in the enzymatic reaction of rnase rh, several mutant enzymes at tyr57 and trp49 were prepared by protein engineering and their enzymatic properties were investigated. among the four mutant enzymes at trp49 (w49f, w49y, w49a, and w49i), w49f showed 16% of the activity of the native enzyme, but the others (w49y, w49a, and w49i) showed greatly decreased activity. the data showed that trp49 is very important for the enzyme activity. among 8 mutant e ... | 1996 | 8907169 |
| carboxyl groups and tryptophan residues in the active site of rhizopus niveus glucoamylase. | functionally important carboxyl groups in the glucoamylase, gluc1, from rhizopus niveus were investigated by site-specific modification using water-soluble carbodiimide, 1-ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide, and nucleophiles. a total of 7.5 carboxyl groups of the 37 present in gluc1 were substituted in the presence of the substrate maltose, and there was a slight loss of enzymatic activity. after removal of maltose, re-treatment of the deprotected enzyme reduced its activity to 3% wit ... | 1999 | 10629972 |
| enzymatic properties of double mutant enzymes at asp51 and trp49 and asp51 and tyr57 of rnase rh from rhizopus niveus. | mutation of asp51 of a base-nonspecific rnase, rnase rh, to ser, thr, or gln makes the enzyme more preferential for the dinucleoside phosphate (xpy) having g and c at the 5'-side (x). on the other hand the mutation of one of the b1 site components, tyr57 to trp, and trp49 to phe makes the enzyme more preferential for purine bases and pyrimidine bases, respectively. in this study, to obtain more specific rnases and rnases with different base specificity, we prepared double-mutant enzymes that hav ... | 1997 | 9404071 |
| role of histidine 46 in the hydrolysis and the reverse transphosphorylation reaction of rnase rh from rhizopus niveus. | in order to study the reaction mechanism of rnase rh from rhizopus niveus, the rates of cleavage of four 2',3'-cyclic nucleotides by mutant enzymes of rnase rh, h46f, h109f, e105q, and k108l were measured. h46f is virtually inactive towards cyclic nucleotides, but h109f hydrolyzed these substrates at 0.7-4.5% of the rates of the native rnase rh. the other mutants hydrolyzed 2',3'-cyclic nucleotides at 15-20% of the rates of the native enzyme. relative enzymatic activities towards four cyclic nuc ... | 1997 | 9192724 |
| interesterification biocatalysis of purified lipase fractions from rhizopus niveus. | | 1996 | 8958094 |
| the crystal structure of lipase ii from rhizopus niveus at 2.2 a resolution. | the crystal and molecular structure of lipase ii from rhizopus niveus was analyzed using x-ray single crystal diffraction data at a resolution of 2.2 a. the structure was refined to an r-factor of 0.19 for all available data. this lipase was purified and crystallized as lipase i, which contains two polypeptide chains combined through non-covalent interaction. however, during crystal growth, lipase i was converted to lipase ii, which consists of a single polypeptide chain of 269 amino acid residu ... | 1996 | 8902613 |
| crystallization of a new class of microbial ribonuclease from rhizopus niveus. | crystals of ribonuclease rh, a new class of microbial ribonuclease from rhizopus niveus, were obtained from polyethylene glycol 8000 solution by a vapour diffusion technique in the hanging drop mode. two crystal forms, type i and type ii, were obtained from the same droplet solution. both forms belong to the space group p2(1)2(1)2(1), but their cell dimensions are markedly different: a = 68.3 a, b = 73.0 a, c = 50.0 a for type i and a = 67.5 a, b = 72.3 a, c = 44.2 a for type ii. the type i crys ... | 1989 | 2738921 |
| primary structure of a base non-specific ribonuclease from rhizopus niveus. | the primary structure of a base non-specific ribonuclease from rhizopus niveus (rnase rh) was determined by nucleotide sequence analysis of the dna fragment encoding rnase rh gene including signal peptide sequence, and amino acid sequence analysis of the peptide obtained from rnase rh and rnase rh' (a protease-modified rnase rh created during the course of purification). the sequence determined was: mkavlalatligstlasscssta lscsnsansdtccspeyglvvlnmqwapgygpanaftlhglwpdkcsgayapsggcdsn rasssiasviksk ... | 1988 | 3391995 |
| isolation and sequencing of a genomic clone encoding aspartic proteinase of rhizopus niveus. | a gene encoding rhizopus niveus aspartic proteinase was isolated from an r. niveus genomic library by using oligonucleotides probes corresponding to its partial amino acid sequence, and its nucleotide sequence was determined. by comparing its deduced amino acid sequence with the amino acid sequence of rhizopuspepsin (5, 26), we concluded that the r. niveus aspartic proteinase gene has an intron within its coding region and that it has a preproenzyme sequence of 66 amino acids upstream of the mat ... | 1988 | 3275615 |
| characterization, by the binding of d-mannonolactone, of the subsites adjacent to the catalytic site of glucoamylase from rhizopus niveus. | | 1987 | 3117364 |
| static and kinetic studies by fluorometry on the interaction between gluconolactone and glucoamylase from rh. niveus. | a transition-state analog, gluconolactone, was found to partially quench the protein fluorescence of glucoamylase [ec 3.2.1.3] from rhizopus niveus. the interaction between gluconolactone and the enzyme was studied statically and kinetically at ph 4.5 in terms of fluorescence change. the dissociation constant kd of the enzyme-analog complex determined by fluorometric titration at 25 degrees (kd = 1.6 mm) was in good agreement with that obtained by difference spectrophotometric titration (ohnishi ... | 1977 | 845140 |
| studies on the subsite structure of amylases. iii. inhibition by gluconolactone of the hydrolysis of maltodextrin catalyzed by glucoamylase from rhizopus niveus. | inhibition by gluconic acid-1 : 5-lactone (gluconolactone) and phenyl alpha-glucoside of the hydrolysis of maltodextrin catalyzed by glucoamylase [ec 3.2.1.3] from rhizopus niveus was investigated in relation to the subsite structure of the enzyme. inhibition by gluconolactone was of the mixed type, whereas that by phenyl alpha-glucoside was purely competitive. these inhibition types were consistent with a theoretical prediction based on the assumption that gluconolactone and phenyl alpha-glucos ... | 1976 | 956133 |
| studies on the subsite structure of amylases. iv. tryptophan residues of glucoamylase from rhizopus niveus studied by chemical modification with n-bromosuccinimide. | chemical modification of glucoamylase [ec 3.2.1.3] from rhizopus niveus by n-bromosuccinimide was carried out to investigate the role of tryptophan residues in the enzyme-catalyzed reaction and their location in the enzyme subsites. of the ten tryptophan residues of the enzyme four could be modified. the two more reactive residues were confirmed not be essential for the catalytic activity for the hydrolysis of maltodextrin and phenyl alpha-maltoside. complete loss of the catalytic activity, howe ... | 1976 | 939754 |
| alpha-secondary tritium kinetic isotope effects for the hydrolysis of alpha-d-glucopyranosyl fluoride by exo-alpha-glucanases. | alpha-secondary tritium kinetic isotope effects ranging from 1.17 to 1.26 were measured for the hydrolysis of alpha-d-glucopyranosyl fluoride (forming beta-d-glucose) catalyzed by several glucoamylases and a glucodextranase. these results indicate that cleavage of the c-f bond is slow and that the enzymic transition state has significant oxo-carbonium ion character. strong support for this conclusion is provided by the agreement found in the case of rhizopus niveus glucoamylase (alpha-tv/k 1.26; ... | 1989 | 2722796 |