| acid proteases from species of mucor. iii. interaction with concanavalin a and concanavalin a sepharose. | the reaction of mucor miehei protease with concanavalin a was followed by a turbidimetric assay in the ph range 5-8. at ph 4.0, no turbidity developed but binding of the enzyme to concanavalin a could be demonstrated by gel filtration. two fractions of apparent molecular weight 65000 and 52000 were isolated, the 65000 molecular weight species apparently representing a protomer of concanavalin a (24000) bound to the enzyme. an analysis of the circular dichroism spectrum of this complex suggested ... | 1976 | 4202 |
| acid proteases from species of mucor. iv. hydrogen-tritium exchange of mucor miehei protease. | the kinetics of hydrogen-tritium exchange were studied in the range ph-3 for both the fully and partially tritiated protein. exchange constants for an intermediate class and slow class of hydrogens were determined and found to give a parabolic curve characteristic of acid and base catalysis about the observed phmin of 4.03. the anomalous rate retardation on the acid portion of the curve was attributed to electrostatic interactions which could be evaluated quantitatively from the titration data. ... | 1976 | 5184 |
| carbohydrate nutrition of mucor miehei and m. pusillus. | | 1976 | 6908 |
| structural and functional determinants of mucor miehei protease. v. enthalpy changes upon thermal denaturation in solution of varying ph. | the thermal denaturation of mucor meihei protease was studied as a function of ph by differential scanning calorimetry. in both citric acid-na2hpo4 and in acetic acid-sodium acetate buffers, maximum thermal stability was at ph 4.0-4.2. however, the maximum enthalpy changes associated with the denaturation process were buffer-dependent and occurred between ph values of 4.7 and 5.7. | 1975 | 235314 |
| action of milk-clotting enzymes on beta-caseins from buffalo's and cow's milk. | beta-caseins isolated from buffalo's and cow's milk were hydrolysed either with rennet or with microbial proteases from mucor miehei, m. pusillus lindt or endothia parasitica. the degradation products were separated by polyacrylamide-gel electrophoresis and the residual beta-casein was determined quantitatively after various times. the electrophoretic patterns of the degradation products of buffalo and bovine beta-casein produced by the different enzymes were not identical. beta-casein of buffal ... | 1976 | 791978 |
| structural and functional determinants of mucor miehei protease vi. inactivation of the enzyme by diazoacetyl norleucine methyl esters, pepstatin and 1,2-epoxy-30(p-nitro-phenyoxy)propane. | mucor miehei protease (ec 3.4.21 -- ), an acid protease of fungal origin, was rapidly inhibited at ph 5.0 and 10 degrees c by a 78-fold molar excess of diazoacetyl norleucine methyl ester (n2ac-nle-ome) when simultaneously added with a 78-fold molar excess of cu(ii). preincubation with cu(ii) before the addition of n2ac-nle-ome reduced the initial rate of activity loss presumably due to a copper-induced structural change as deduced from an examination of cd spectra. cof norleucine and 1.02 +/- 0 ... | 1977 | 831836 |
| hydrolysis of animal fat and vegetable oil with mucor miehei esterase. properties of the enzyme. | | 1977 | 893842 |
| amylase production by mucor miehei and m. pusillus. | | 1976 | 980001 |
| some effects of temperature on zygospore formation in mucor miehei. | | 1976 | 1012305 |
| acid proteases from species of mucormii. partial characterization of the acid protease produced by a strain of mucor miehei isolated in cuba. | the acid protease produced by a strain of mucor miehei isolated in cuba was purified by column electrofocusing and partially characterized as to amino-acid composition, molecular weight, helical content, total carbohydrate content, and approximate isoelectric point; a detailed comparison of these results was reported previously for mucor miehei protease (ottesen, m. & rickert, w;s. (1970) c.r. trav. labmcarlsberg 37, 301) suggested that the two enzymes are similar but not identicalmthis conclusi ... | 1975 | 1125813 |
| interesterification of phosphatidylcholine with lipases in organic media. | lipases were investigated with respect to their ability to catalyse the incorporation of fatty acids into phosphatidylcholine (pc) by interesterification reactions. the enzymes were dried onto solid support materials and the conversions were carried out in water-saturated toluene. three lipases (two fungal and one plant enzyme) had the desired activity; immobilized lipase from mucor miehei (lipozyme) was the most active enzyme. the lipozyme-catalysed interesterification was selective for the sn- ... | 1990 | 1366637 |
| recovery of metal ions by microfungal filters. | many microfungi contain chitin/chitosan as an integral part of the cell wall structure. the binding of toxic and heavy metal ions by chitosan or partly deacetylated chitin is a direct consequence of the base strength of the primary amine group and is most effective for those metals that form complexes with ammonia. of the microfungi studied, hyphae from mucor mucedo and rhizomucor miehei, after treatment with hydroxide to expose the chitin/chitosan, were found to be most effective in the capture ... | 1990 | 1366966 |
| 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 |
| strategies for enzymatic esterification in organic solvents: comparison of microaqueous, biphasic, and micellar systems. | the kinetics of butyl butyrate synthesis by a lipase from mucor miehei in different types of organic media were investigated. the three systems studied were a microaqueous medium containing enzyme in suspension in hexane, a water-hexane two-phase system, and reverse micelles. the synthesis of butyl butyrate was possible in all cases because of a favorable partition of the ester into the organic solvent. a sufficient stirring rate was necessary to achieve good reaction rates in the case of the li ... | 1992 | 1368967 |
| the crystal and molecular structure of the rhizomucor miehei triacylglyceride lipase at 1.9 a resolution. | the crystal and molecular structure of a triacylglyceride lipase (ec 3.1.1.3) from the fungus rhizomucor miehei was analyzed using x-ray single crystal diffraction data to 1.9 a resolution. the structure was refined to an r-factor of 0.169 for all available data. the details of the molecular architecture and the crystal structure of the enzyme are described. a single polypeptide chain of 269 residues is folded into a rather unusual singly wound beta-sheet domain with predominantly parallel stran ... | 1992 | 1404390 |
| proteolytic activity of proteinases on macropeptide isolated from kappa-casein. | proteolytic activities of chymosin, bovine pepsin, mucor miehei rennet, cryphonectria parasitica (formerly endothia parasitica) rennet, trypsin, and chymotrypsin on kappa-casein macropeptide were measured. macropeptide solutions (10 mg/ml of .05 m, ph 6.6 phosphate buffer) were incubated with the enzymes at 37 degrees c for various times, and their reactions were stopped by adding .025 ml of pepstatin (1 mg/ml of methanol). peptides released from kappa-casein macropeptide were then fractionated ... | 1992 | 1500545 |
| stereoselectivity of lipases: esterification reactions of octadecylglycerol. | stereoselectivity of several triacylglycerol lipases (ec 3.1.1.3) has been investigated in the enzymatic esterification of rac-1-o-octadecylglycerol with oleic acid in the presence of organic solvents, such as hexane. x-1(3)-o-octadecylmonooleoylglycerols were the only products formed with most lipases; considerable proportions of x-1(3)-o-octadecyldioleoylglycerols were also formed with the lipase from candida cylindracea. the mixtures of unesterified enantiomeric substrates, i.e., x-1(3)-o-oct ... | 1992 | 1511492 |
| rhizomucor miehei lipase remains highly active at water activity below 0.0001. | the lipase from rhizomucor miehei adsorbed on polymer beads retains substantial catalytic activity even after exhaustive drying, and the use of dry box procedures to prevent entry of atmospheric water. rates of esterification and transesterification (alcoholysis) were measured while stirred in hexane pre-dried to similar low water activity (aw). the rate of dodecyl decanoate synthesis was over 30% of that at the optimum (aw 0.55) after drying with anhydrous cuso4 (aw less than 10(-3)) or mgo (aw ... | 1992 | 1577162 |
| 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 |
| catalysis at the interface: the anatomy of a conformational change in a triglyceride lipase. | the crystal structure of an extracellular triglyceride lipase (from a fungus rhizomucor miehei) inhibited irreversibly by diethyl p-nitrophenyl phosphate (e600) was solved by x-ray crystallographic methods and refined to a resolution of 2.65 a. the crystals are isomorphous with those of n-hexylphosphonate ethyl ester/lipase complex [brzozowski, a. m., derewenda, u., derewenda, z. s., dodson, g. g., lawson, d. m., turkenburg, j. p., bjorkling, f., huge-jensen, b., patkar, s. a., & thim, l. (1991) ... | 1992 | 1737010 |
| cloning, expression and characterization of a cdna encoding a lipase from rhizopus delemar. | a lambda gt11 cdna library was constructed in escherichia coli using poly(a)-selected mrna from the fungus, rhizopus (rp.) delemar. lipase-producing members of the library were identified by means of a phenotypic score wherein the release of fatty acids by lipase causes a characteristic color change in the growth medium. one such isolate contained a 1287-bp insert (lip cdna) which hybridizes to 1.25- to 1.35-kb mrna species from rp. delemar. the lipase produced in e. coli containing the lip cdna ... | 1991 | 1756969 |
| relationships among serine hydrolases: evidence for a common structural motif in triacylglyceride lipases and esterases. | a detailed analysis of the highly refined (1.9 a resolution) molecular model of the fungal (rhizomucor miehei) triglyceride lipase reveals a unique conformation of the oligopeptide containing the active serine (ser 144) residue. it consists of a six-residue beta-strand (strand 4 of the central sheet), a four-residue turn of type ii' with serine in the epsilon conformation, and a buried alpha-helix packed in a parallel way against strands 4 and 5 of the central beta-pleated sheet. it is shown tha ... | 1991 | 1818588 |
| cloning and structure of the mono- and diacylglycerol lipase-encoding gene from penicillium camembertii u-150. | a gene (mdla) encoding mono- and diacylglycerol lipase (mdgl) from penicillium camembertii u-150 has been cloned using a 0.9-kb dna fragment, generated by mixed oligodeoxyribonucleotide (oligo)-primed polymerase chain reaction (pcr), as a probe. comparison of the nucleotide sequence of the gene and its cdna clone, obtained by pcr, revealed the presence of two short introns (56 and 53 bp). two transcription start points (tsp) were localized by primer extension analysis at 37 and 30 bp upstream fr ... | 1991 | 1879699 |
| a kinetic and equilibrium study of the denaturation of aspartic proteinases from the fungi, endothia parasitica and mucor miehei. | kinetic and equilibrium analyses of the denaturation of endothia parasitica and mucor miehei aspartic proteinases were performed using enzyme activity and ultraviolet absorption as indices of denaturation. denaturation of these proteinases was shown to be irreversible, suggesting that the conformations of these aspartic proteinases may be predetermined in their zymogens. thermal and guanidine hydrochloride denaturation of these proteinases produced first-order, two-state, kinetic behaviour. equi ... | 1991 | 2001389 |
| a model for interfacial activation in lipases from the structure of a fungal lipase-inhibitor complex. | lipases are hydrolytic enzymes which break down triacylglycerides into free fatty acids and glycerols. they have been classified as serine hydrolases owing to their inhibition by diethyl p-nitrophenyl phosphate. lipase activity is greatly increased at the lipid-water interface, a phenomenon known as interfacial activation. x-ray analysis has revealed the atomic structures of two triacylglycerol lipases, unrelated in sequence: the human pancreatic lipase (hpl)4, and an enzyme isolated from the fu ... | 1991 | 2046751 |
| asperfuran, a novel antifungal metabolite from aspergillus oryzae. | asperfuran is a novel antifungal dihydrobenzofuran derivative produced by a strain of aspergillus oryzae. asperfuran weakly inhibited chitin synthase from coprinus cinereus. this inhibition could be abolished by the addition of egg lecithin. in the agar diffusion assay asperfuran induced morphological changes in mucor miehei at very low concentrations (20 ng/disc) while growth was only partly inhibited. in hela s3 and l1210 cells it showed weak cytotoxicity, the ic50 was 25 micrograms/ml. | 1990 | 2143181 |
| kinetic study of esterification by immobilized lipase in n-hexane. | the kinetic of the esterification of oleic acid by ethanol catalyzed by immobilized lipase of mucor miehei in n-hexane as a solvent has been completely studied. the kinetics of the reaction are suggested to agree with a ping-pong bi bi mechanism in which only inhibition by excess of ethanol has been identified. values of all apparent kinetic parameters were computed. no evidence of any significant external diffusional limitation which could account for these values has been detected. optimizatio ... | 1990 | 2265698 |
| a serine protease triad forms the catalytic centre of a triacylglycerol lipase. | true lipases attach triacylglycerols and act at an oil-water interface; they constitute a ubiquitous group of enzymes catalysing a wide variety of reactions, many with industrial potential. but so far the three-dimensional structure has not been reported for any lipase. here we report the x-ray structure of the mucor miehei triglyceride lipase and describe the atomic model obtained at 3.1 a resolution and refined to 1.9 a resolution. it reveals a ser..his..asp trypsin-like catalytic triad with a ... | 1990 | 2304552 |
| bacereutin, an antifungal antibiotic isolated from metabolites of bacillus cereus chu 130. | an antifungal metabolite, bacereutin, was isolated from culture filtrate of bacillus cereus chu 130. the bacterium was isolated from soils collected in changhwa county, taiwan, and was grown in soybean meal-mannitol broth for production of the antibiotic metabolite. the antibiotic metabolite was isolated by adsorption column chromatography of amberite xad-2 and was purified by passing through the chromatographic columns packed with dowex 50w-x8, sephadex lh 20 and biogel p-2. the antibiotic meta ... | 1989 | 2484044 |
| specificity of milk-clotting enzymes towards bovine kappa-casein. | limited proteolysis of bovine kappa-casein has been investigated with porcine pepsin a and c, and with the 2 microbial proteinases mucor miehei proteinase and endothia parasitica proteinase. the liberated c-terminal glycomacropeptide of kappa-casein was isolated after precipitation in 3% trichloroacetic acid followed by high-performance gel-permeation chromatography on a tsk g3000 sw column. from amino acid analyses and n-terminal sequencing of the liberated peptide it is concluded that porcine ... | 1989 | 2495817 |
| antibiotics from basidiomycetes. xxxi. aleurodiscal: an antifungal sesterterpenoid from aleurodiscus mirabilis (berk. & curt.) höhn. | aleurodiscal, an antifungal antibiotic has been isolated from mycelial cultures of aleurodiscus mirabilis (berk. & curt.) höhn. it causes abnormal apical branchings of mucor miehei hyphae at very low concentrations. the structure and absolute configuration of the antibiotic has been determined by a single crystal x-ray analysis and hydrolysis to d-(+)-xylose. aleurodiscal is a hydroxysesterterpene aldehyde beta-d-xyloside with a novel carbon skeleton. | 1989 | 2500412 |
| rhizomucor miehei triglyceride lipase is processed and secreted from transformed aspergillus oryzae. | the cdna encoding the precursor of the rhizomucor miehei triglyceride lipase was inserted in an aspergillus oryzae expression vector. in this vector the expression of the lipase cdna is under control of the aspergillus oryzae alpha-amylase gene promoter and the aspergillus niger glucoamylase gene terminator. the recombinant plasmid was introduced into aspergillus oryzae, and transformed colonies were selected and screened for lipase expression. lipase-positive transformants were grown in a small ... | 1989 | 2586234 |
| storage temperature and viability of sporangiospores of potentially human pathogenic species of rhizomucor from nigerian tobacco. | the effects of temperature on storage and viability of asexual spores of rhizomucor pusillus (lindt) schipper and rhizomucor miehei (cooney and emerson) schipper were studied. an optimal germination temperature of 35 degrees c was recorded for both species with good results obtained around 40 degrees c. on prolonged storage of the spores at various temperatures (-19 degrees c, 4 degrees c, 30 degrees c, 37 degrees c), the best results were obtained at 4 degrees c and 30 degrees c. very rapid los ... | 1989 | 2746473 |
| primary structure of a precursor to the aspartic proteinase from rhizomucor miehei shows that the enzyme is synthesized as a zymogen. | in order to characterize the zymogen of the milk-clotting enzyme from rhizomucor miehei, we constructed a cdna library on pbr327 in escherichia coli. aspartic proteinase-specific recombinants were isolated by colony hybridization to a specific oligonucleotide mixture, and the cdna sequence corresponding to a precursor form of the enzyme was determined. the deduced amino acid sequence shows that this secreted fungal proteinase is synthesized as a precursor. the first 22 amino acid residues in thi ... | 1986 | 3329734 |
| rhizomucor miehei triglyceride lipase is synthesized as a precursor. | a rhizomucor miehei cdna library constructed in escherichia coli was screened with synthetic oligonucleotides designed from knowledge of a partial amino acid sequence of the secreted triglyceride lipase (triacylglycerol acylhydrolase ec 3.1.1.3) from this fungus. lipase-specific recombinants were isolated and their insert sequenced. unlike characterized bacterial and mammalian triglyceride lipases, the fungal enzyme is synthesized as a precursor, including a 70 amino acid residue propeptide betw ... | 1988 | 3419283 |
| primary structure of mucor miehei aspartyl protease: evidence for a zymogen intermediate. | the gene encoding the aspartyl protease of the filamentous fungus mucor miehei has been cloned in escherichia coli and the dna sequenced. the deduced primary translation product contains an n-terminal region of 69 amino acid (aa) residues not present in the mature protein. by analogy to the evolutionarily related mammalian gastric aspartyl proteases it is inferred that the primary secreted product is a zymogen containing a 47-aa propeptide. this propeptide is presumably removed in the later step ... | 1986 | 3549462 |
| structural and functional determinants of mucor miehei protease. ii. circular dichroic studies on the native and periodate-oxidized enzyme. | | 1973 | 4357565 |
| structural and functional determinants of mucor miehei protease. iv. nitration and spectrophotometric titration of tyrosine residues. | | 1974 | 4433573 |
| bond specificity, active site and milk clotting mechanism of the mucor miehei protease. | | 1972 | 4573298 |
| acid proteases from species of mucor: molecular weight on mucor miehei protease from amino acid analysis data. | | 1973 | 4775436 |
| synthesis of cellulase by mucor pusillus and mucor miehei. | | 1974 | 4822120 |
| structural and functional determinants of mucor miehei protease. i. modification of the nh 2 terminus and lysine residues by carbamylation. | | 1972 | 5038703 |
| the effect of temperature on spore germination and growth of mucor miehei in submerged culture. | | 1972 | 5070715 |
| the isolation and partial characterization of an acid protease produced by mucor miehei. | | 1970 | 5450445 |
| the degradation of the b-chain of oxidized insulin by mucor miehei protease. | | 1970 | 5502290 |
| avermectin modulation of gaba binding to membranes of rat brain, brine shrimp and a fungus, mucor miehei. | high affinity [3h]gaba (gamma-aminobutyric acid) binding sensitive to muscimol and bicuculline was detected in membranes derived from rat brain and brine shrimp. avermectin stimulated this gaba binding with maximum stimulation seen in these membranes at 400 and 40-80 ng/ml, respectively. this avermectin stimulation of gaba binding was cl--dependent, bicuculline and picrotoxin-sensitive and was associated with an increase in bm but not kd of the systems. the membranes from mucor miehei also exhib ... | 1984 | 6088460 |
| 8006-i, an antibiotic from amblyosporium spongiosum (pers.) hughes sensu pirozynski. ii. biological properties. | 8006-i is an antibacterial antibiotic with a rather broad spectrum of activity. the minimum inhibitory concentrations for the most sensitive bacteria are in the range of one to ten micrograms/ml. yeasts are not affected by concentrations up to 100 micrograms/ml. some filamentous fungi like fusarium oxysporum and mucor miehei are inhibited at 100 micrograms/ml. in ehrlich carcinoma ascitic cells the incorporation of uridine and leucine and to a lesser extent that of thymidine is reduced. in isola ... | 1982 | 6178718 |
| antigenic characterization of some potentially pathogenic mucoraceous fungi. | the antigenic profiles of 10 mucoraceous fungi--absidia corymbifera, mortierella wolfii, mucor miehei, m. pusillus, m. racemosus, rhizopus arrhizus, r. microsporus, r. oryzae, r. rhizopodiformis, r. stolonifer,--candida albicans and aspergillus fumigatus were compared by crossed immunoelectrophoresis (xie). antigen-rich material was obtained from homogenized hyphae (or yeasts in the case of c. albicans), and antisera by multiple subcutaneous innoculation of rabbits with macerated but viable hyph ... | 1982 | 6182620 |
| inhibition of chitin metabolism by avermectin in susceptible organisms. | avermectin inhibits mucor miehei and artemia salina chitin synthesis and to a degree dna synthesis in the former. the antibiotic interferes with chitin turnover in brine shrimp and inhibits streptomyces antibioticus chitinase activity in vitro. in light of the proposed mode of action of avermectin and the anomolies in the literature, it is proposed that avermectin can kill susceptible organisms not only by a neurotoxic mechanism but also by inhibiting chitin turnover and synthesis at low concent ... | 1984 | 6725140 |
| kinetic studies on the action of mucor pusillus, mucor miehei acid proteases and chymosins a and b on a synthetic chromophoric hexapeptide. | the action of two milk-clotting fungal proteases from mucos pusillus and mucor miehei and of chymosins a and b on the hexapeptide, leu-ser-phe(no2)-nle-ala-leu-ome, and on kappa-casein were studied. the effects of ph and temperature on the initial rates of hydrolysis of the hexapeptide were examined. crystalline chymosin and m. pusillus protease exhibited optimal activities around 49 and 55 degrees c, respectively, whereas the optimum temperature for m. miehei protease is higher than 63 degrees ... | 1980 | 6768392 |
| effects of small concentrations of mucor miehei protease on stability of sterile milk-based dietetic foods. | four commercial sterile milk-based dietetic products were inoculated aseptically with small concentrations of a commericial milk clotting enzyme derived from mucor miehei and incubated at 30 c for 32 wk. one of the products, sustacal, exhibited no observable changes in body and texture during storage. enzyme concentrations of 1 x 10(-4) chymosin units per milliliter or higher induced undesirable changes in the body of the other three products, enfamil ready-to-use, enfamil concentrate, and metre ... | 1980 | 6989865 |
| comparative study of two mucor miehei acid proteinases. purification and some molecular properties. | | 1980 | 6993248 |
| nutritional physiology of pathogenic species of thermophilic mucor. | some aspects of the nutritional physiology of zoopathogenic mucor pusillus lindt and mucor miehei cooney & emerson were studied at 37 degrees c. only asexual spores (sporangiospores) were produced on all the media used. a ph range of 5.0-6.0 was found to be best for the growth and sporulation of both species. the fungi were able to utilize various sources of carbon and nitrogen tested except l-sorbose and dl-tryptophan on which no growth was recorded. of the carbon sources, the best results were ... | 1981 | 7292206 |
| thermophilic mycoflora of cigarettes and cured tobacco leaves. | nine species of thermophilic fungi were obtained from retailed packets of imported and locally manufactured brands of cigarettes and from cured tobacco leaves. they include known human pathogens such as thermoascus aurantiacus miehe sensu apinis, mucor pursillus lindt and mucor miehei cooney and emerson. chaetomium thermophile la touche, humicola insolens cooney and emerson, thermoascus crustaeus (apinis and chesters) stolk and mucor miehei have not been previously reported on tobacco products. ... | 1980 | 7383143 |
| 3d-structures of the lipase from rhizomucor miehei at different temperatures and computer modelling of a complex of the lipase with trilaurylglycerol. | the lipase of rhizomucor miehei was measured at two different wavelengths (synchroton lambda = 1.06 a and at a rotating anode lambda = 1.542 a) and two temperatures (293 and 110 k). the structure could be solved using the c alpha-coordinates from the brookhaven data base (code name 1tgl). both structures were refined to r-values of 18.7% (synchrotron 293 k) and 20.0% (rotating anode 110 k) at a resolution of 8-2.3 and 8-2.5 a, respectively. both structures are almost identical to the original 1t ... | 1993 | 7763528 |
| kinetic studies of mucor miehei lipase in phosphatidylcholine microemulsions. | ethanol-oleic acid esterification by a free and microencapsulated lipase from mucor miehei, using dodecane as solvent and phosphatidylcholine as surfactant, was studied. the initial esterification rate was influenced by the water content in the biphasic system. kinetic studies with free and microencapsulated enzyme showed that the microencapsulation led to an increase of the kinetic parameters (vmax and km), probably due to an increase of the interfacial area. the reaction rate was also affected ... | 1993 | 7763531 |
| use of aspergillus overproducing mutants, cured for integrated plasmid, to overproduce heterologous proteins. | aspergillus niger var. awamori was previously transformed with a vector designed to express a fused glucoamylase-prochymosin gene and bearing the neurospora crassa pyr4 gene as a selectable marker. mutant strains that overproduced the glucoamylase-prochymosin fusion protein were derived from one of the transformants. despite the fact that the expression vector was integrated into the genome of these strains it was possible to obtain strains from which the vector sequences had been removed. this ... | 1993 | 7764120 |
| a structural model of mono- and diacylglycerol lipase from penicillium camembertii. | the amino acid sequence of lipase from penicillium camembertii was aligned with rhizomucor miehei lipase without permitting any deletion or insertion in the structurally conserved regions. this lipase was classified into the r. miehei lipase family, because 33% of the residues were identical and 18% of the exchanges were conserved. a graphic molecular model for p. camembertii lipase was built using information from the sequence and x-ray structure of r. miehei lipase. the primary specificity poc ... | 1994 | 7764452 |
| computer modeling of substrate binding to lipases from rhizomucor miehei, humicola lanuginosa, and candida rugosa. | the substrate-binding sites of the triacyl glyceride lipases from rhizomucor miehei, humicola lanuginosa, and candida rugosa were studied by means of computer modeling methods. the space around the active site was mapped by different probes. these calculations suggested 2 separate regions within the binding site. one region showed high affinity for aliphatic groups, whereas the other region was hydrophilic. the aliphatic site should be a binding cavity for fatty acid chains. water molecules are ... | 1994 | 7833809 |
| 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 |
| inhibition of lipases by phosphonates. | ethyl hexylchlorophosphonate and analogues thereof were investigated as inhibitors of lipases. both microbial and mammalian lipases were irreversibly inhibited. the inhibition could be monitored by p-nitrophenol release from the corresponding ethyl p-nitrophenyl hexylphosphonate inhibitor. quantitative analysis of the data indicated that a 1:1 lipase-inhibitor complex was formed during inhibition. enantioselective inhibition was found for the lipases derived from candida antarctica and rhizomuco ... | 1994 | 7858978 |
| improvement of heavy metal biosorption by mycelial dead biomasses (rhizopus arrhizus, mucor miehei and penicillium chrysogenum): ph control and cationic activation. | fungal mycelial by-products from fermentation industries present a considerable affinity for soluble metal ions (e.g. zn, cd, ni, pb, cr, ag) and could be used in biosorption processes for purification of contaminated effluents. in this work the influence of ph on sorption parameters is characterized by measuring the isotherms of five heavy metals (ni, zn, cd, ag and pb) with rhizopus arrhizus biomass under ph-controlled conditions. the maximum sorption capacity for lead was observed at ph 7.0 ( ... | 1994 | 7917420 |
| molecular dynamics simulations of an enzyme surrounded by vacuum, water, or a hydrophobic solvent. | we report on molecular dynamics simulations of a medium-sized protein, a lipase from rhizomucor miehei, in vacuum, in water, and in a nonpolar solvent, methyl hexanoate. depending on force field and solvent, the molecular dynamics structures obtained as averages over 150 ps had root-mean-square deviations in the range of 1.9 to 3.6 a from the crystal structure. the largest differences between the structures were in hydrogen bonding and exposed surface areas of the protein. the surface area incre ... | 1994 | 7948673 |
| 'organic phase buffers' control biocatalyst activity independent of initial aqueous ph. | combinations of triisooctylamine with its hydrochloride, or of triphenylacetic acid with its na+ salt, can function as buffers for use during biocatalysis in organic media. they can control the ph of an adjacent aqueous phase, even though both forms of each buffer remain in the organic phase. with 0.1 m aqueous nacl, the mid-point ph values obtained with the two buffer systems are around ph 4.5 and 7.0, respectively. the activity of an immobilized subtilisin carlsberg shows a strong dependence o ... | 1994 | 8003520 |
| relationship between water activity and catalytic activity of lipases in organic media. effects of supports, loading and enzyme preparation. | the rates of synthesis of dodecyl decanoate in hexane have been measured as a function of water activity (aw), for various immobilised preparations of the lipases from rhizomucor miehei and candida rugosa. only very large changes in the amount of enzyme adsorbed to the support affect the shape of the rate/aw profile; at the highest loadings the profiles tend to become somewhat flatter. a similar levelling can be obtained by pre-adsorbing an inert protein. the effect is probably due to adjacent p ... | 1994 | 8020484 |
| current progress in crystallographic studies of new lipases from filamentous fungi. | lipases from filamentous fungi have been studied extensively over many years. they exhibit properties attractive for industrial applications, e.g. in laundry detergents, tanning and paper industries and stereospecific organic synthesis. enzymes from the fungi rhizomucor miehei and geotrichum candidum have been among the first neutral lipases to be characterized structurally by x-ray diffraction methods. in this paper we report a preliminary account of crystallographic studies of three other fung ... | 1994 | 8029211 |
| lipases from rhizomucor miehei and humicola lanuginosa: modification of the lid covering the active site alters enantioselectivity. | the homologous lipases from rhizomucor miehei and humicola lanuginosa showed approximately the same enantioselectivity when 2-methyldecanoic acid esters were used as substrates. both lipases preferentially hydrolyzed the s-enantiomer of 1-heptyl 2-methyldecanoate (r. miehei: es = 8.5; h. lanuginosa: es = 10.5), but the r-enantiomer of phenyl 2-methyldecanoate (er = 2.9). chemical arginine specific modification of the r. miehei lipase with 1,2-cyclohexanedione resulted in a decreased enantioselec ... | 1993 | 8136025 |
| an overview of the safety evaluation of the rhizomucor miehei lipase enzyme. | the rhizomucor miehei lipase enzyme expressed in aspergillus oryzae, is used in the production of specialty fats, the production of existing fats from new raw materials, or new fats with improved nutritional or functional qualities. it is produced by a. oryzae containing the structural gene for the precursor of r. miehei triglyceride lipase. it was subjected to a series of toxicological tests to document the safety in use. the enzyme preparation was not found to be mutagenic either in bacterial ... | 1994 | 8181628 |
| crystallization and preliminary crystallographic studies of the precursor and mature forms of a neutral lipase from the fungus rhizopus delemar. | a neutral lipase from the filamentous fungus rhizopus delemar has been crystallized in both its proenzyme and mature forms. although the latter crystallizes readily and produces a variety of crystal forms, only one was found to be suitable for x-ray studies. it is monoclinic (c2, a = 92.8 a, b = 128.9 a, c = 78.3 a, beta = 135.8) with two molecules in the asymmetric unit related by a noncrystallographic diad. the prolipase crystals are orthorhombic (p2(1)2(1)2(1), with a = 79.8 a, b = 115.2 a, c ... | 1994 | 8202471 |
| theoretical studies of rhizomucor miehei lipase activation. | computational methods have been used to study the extensive conformational change of rhizomucor miehei lipase upon activation. the present study considers the possible activation route, the energies involved and molecular interactions during the conformational change of the lipase in a hydrophobic environment. the conformational change was studied by conventional molecular dynamics methods and with a combined molecular dynamics and mechanics protocol, in which the conformational change was simul ... | 1993 | 8309933 |
| 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 |
| the role of arginines in stabilizing the active open-lid conformation of rhizomucor miehei lipase. | molecular dynamics simulations for the lid covering the active site of rhizomucor miehei lipase [ec 3.1.1.3] postulated that, among other interactions, arg86 in the lid stabilized the open-lid conformation of the protein by multiple hydrogen bonding to the protein surface. chemical modification of arginine residues in r. miehei lipase with 1,2-cyclohexanedione or phenylglyoxal resulted in residual activities in the hydrolysis of tributyrin of 66 and 46%, respectively. tryptic maps of native and ... | 1993 | 8377587 |
| controlling lipase stereoselectivity via the surface pressure. | in the present study, the stereoselectivity of rhizomucor miehei lipase, lipoprotein lipase, candida antarctica b lipase, and human gastric lipase towards racemic dicaprin spread as a monolayer at the air-water interface was investigated. for this purpose we have developed a method with which the enantiomeric excess of the residual substrate can be measured in monomolecular films. the stereoselectivity, which is one of the main aspects of enzymic catalysis, was found to depend on the surface pre ... | 1993 | 8419355 |
| contribution of cutinase serine 42 side chain to the stabilization of the oxyanion transition state. | cutinase from the fungus fusarium solani pisi is a lipolytic enzyme able to hydrolyze both aggregated and soluble substrates. it therefore provides a powerful tool for probing the mechanisms underlying lipid hydrolysis. lipolytic enzymes have a catalytic machinery similar to those present in serine proteinases. it is characterized by the triad ser, his, and asp (glu) residues, by an oxyanion binding site that stabilizes the transition state via hydrogen bonds with two main chain amide groups, an ... | 1996 | 8555209 |
| enzymatic hydrolysis of long-chain n-heterocyclic fatty esters. | incubation of a 1-pyrroline ester [viz. methyl 8-(5-hexyl-1-pyrroline-2-yl)octanoate, 1] with bakers' yeast (saccharomyces cerevisiae) gave the corresponding free fatty acid (1a, 52%). the c = n bond of the 1-pyrroline was not reduced by the yeast. complete hydrolysis of compound 1 was successful using lipase of candida cylindracea (ccl) or lipolase (rhizomucor miehei) under stirred or ultrasound condition. fatty esters containing a pyrrolidine [viz. methyl 8-(cis/trans-5-hexyl-pyrrolidine-2-)oc ... | 1995 | 8569439 |
| theoretical investigation of the dynamics of the active site lid in rhizomucor miehei lipase. | interfacial activation of rhizomucor miehei lipase is accompanied by a hinge-type motion of a single helix (residues 83-94) that acts as a lid over the active site. activation of the enzyme involves the displacement of the lid to expose the active site, suggesting that the dynamics of the lid could be of mechanistic and kinetic importance. to investigate possible activation pathways and to elucidate the effect of a hydrophobic environment (as would be provided by a lipid membrane) on the lid ope ... | 1996 | 8804595 |
| the consequences of engineering an extra disulfide bond in the penicillium camembertii mono- and diglyceride specific lipase. | the extracellular lipase from penicillium camembertii has unique substrate specificity restricted to mono- and diglycerides. the enzyme is a member of a homologous family of lipases from filamentous fungi. four of these proteins, from the fungi rhizomucor miehei, humicola lanuginosa, rhizopus delemar and p. camembertii, have had their structures elucidated by x-ray crystallography. in spite of pronounced sequence similarities the enzymes exhibit significant differences. for example, the thermost ... | 1996 | 8888145 |
| dynamics of proteins in different solvent systems: analysis of essential motion in lipases. | we have investigated the effect of different solvents on the dynamics of rhizomucor miehei lipase. molecular dynamics simulations were performed in water, methyl hexanoate, and cyclohexane. analysis of the 400-ps trajectories showed that the solvent has a pronounced effect on the geometrical properties of the protein. the radius of gyration and total accessibility surface decrease in organic solvents, whereas the number of hydrogen bonds increases. the essential motions of the protein in differe ... | 1996 | 8913568 |
| probing the substrate specificity for lipases. ii. kinetic and modeling studies on the molecular recognition of 2-arylpropionic esters by candida rugosa and rhizomucor miehei lipases. | racemic arylpropionic esters 1-3, precursors of therapeutically important non-steroidal antiinflammatory drugs, were subjected to hydrolyses in the presence of either candida rugosa or rhizomucor miehei crude lipases. the hydrolyses of 1 and 2 proved to be highly enantioselective, whereas 3 was not transformed at all. both the substrate specificity and the enantioselectivity of these lipases were explained through a molecular modeling study involving docking experiments between 1-3 and the amino ... | 1997 | 9048908 |
| essential dynamics of lipase binding sites: the effect of inhibitors of different chain length. | the biochemical activity of enzymes, such as lipases, is often associated with structural changes in the enzyme resulting in selective and stereospecific reactions with the substrate. to investigate the effect of a substrate and its chain length on the dynamics of the enzyme, we have performed molecular dynamics simulations of the native rhizomucor miehei lipase (rml) and lipase-dialkylphosophate complexes, where the length of the alkyl chain ranges from two to 10 carbon atoms. simulations were ... | 1997 | 9089814 |
| crystal structure of the aspartic proteinase from rhizomucor miehei at 2.15 a resolution. | the crystal structure of the aspartic proteinase from rhizomucor miehei (rmp, ec 3. 4. 23. 23) has been refined to 2.15 a resolution to a crystallographic r-value of 0.215 and an rfree of 0.281. the root-mean-square (r.m.s.) error for the atomic coordinates estimated from a luzzati plot is 0.2 a. the r.m.s. deviations for the bond distances and bond angles from ideality are 0.01 a and 1.7 degrees, respectively. rmp contains two domains that consist predominantly of beta-sheets. a large substrate ... | 1997 | 9159482 |
| activity and stability of a rhizomucor miehei lipase in hydrophobic media. | the effects of detergents and organic solvents on a commercial lipase (lipozyme) from rhizomucor miehei were investigated. it was shown that the detergent sodium cholate is possibly an activator of the enzyme, increasing lipase activity 2.5 times (250% of the control) when the enzyme was preincubated with 7 mm cholate. lipozyme activity was over twice as high (230% of the control) in the presence of 80 mm tween 80 or 90 mm tween 20 (polyoxyethylenesorbitan monolaurate), apparently through an add ... | 1997 | 9262001 |
| molecular modelling studies of substrate binding to the lipase from rhizomucor miehei. | lipase enzymes have found increasingly widespread use, especially in biotransformation reactions in organic synthesis. due to their efficiency and high enantioselectivity, they can be employed in a variety of reactions to carry out asymmetric hydrolyses, esterifications and transesterifications. however, the reasons for their stereospecificity have not been fully correlated with the enzyme structure. employing molecular modelling techniques and existing experimental data, a transesterification r ... | 1997 | 9263852 |
| enzymatic hydrolysis of anchovy oil: production of glycerides enriched in polyunsaturated fatty acids. | in an attempt to produce the polyunsaturated fatty acid (pufa)-enriched glycerides, commercially available turkish anchovy oil (pufa content of 27%), was hydrolyzed with 1,3-specific rhizomucor miehei lipase. after the hydrolysis, the triglyceride (tg), diglyceride (dg), monoglyceride (mg), and free fatty acid (ffa) composition of the reaction mixture was determined, and fatty acid components of these fractions were analyzed. r. miehei lipase released pufa extremely slowly, resulting in their ac ... | 1997 | 9429299 |
| biocompatibility of potential wound management products: hydrogen peroxide generation by fungal chitin/chitosans and their effects on the proliferation of murine l929 fibroblasts in culture. | agaricus bisporus, fusarium graminearum, phycomyces blakesleeanus, unbleached and bleached, rhizomucor miehei, and rhizopus oryzae were examined as sources of fungal chitin/chitosan. the nitrogen content of the alkalitreated mycelia/sporangiophores obtained after optimization of culture conditions, and of similarly treated a. bisporus stipes, was 2.87, 1.29, 6.27, 6.50, 4.80, and 4.95% w/w, respectively, which relates to an estimated chitin content of 42, 19, 91, 94, 70, and 72%, respectively. t ... | 1998 | 9457561 |
| studies of lipase-catalyzed esterification reactions of some acetylenic fatty acids. | esterification of five positional isomers of acetylenic fatty acids [viz. 9:1(2a), 11:1(10a), 18:1(6a), 18:1(9a) and 22:1(13a)] of different chain lengths with n-butanol in n-hexane in the presence of eight different lipases [lipozyme im 20 (rhizomucor miehei), lipolase 100t (r. miehei), novozyme 435 (candida antarctica), ppl (porcine pancreatic lipase), ccl (c. cylindracea), ps-d (pseudomonas cepacia), lipase a-12 (aspergillus niger) and lipase ay-30 (c. rugosa)] was studied. 2-nonynoic acid wa ... | 1998 | 9470175 |
| crystal structure of the rhizomucor miehei aspartic proteinase. | | 1998 | 9561231 |
| rhizomucor miehei aspartic proteinases having improved properties. | | 1998 | 9561232 |
| anthranilamides: new antimicroalgal active substances from a marine streptomyces sp. | 2-[methyl-(3-phenylpropionyl)amino]-benzoic acid (1e) was isolated from a culture of marine streptomyces sp. strain b7747. analogous compounds have potential importance as phytotoxic substances, hence compound 1e and the analogues 1a approximately 1d and 1f approximately 3a were synthesised. antimicroalgal activity of the anthranilamide analogues showed that esters 1b, 1f and 2b were more active than the free acids. the minimum inhibitory concentration (mic) against chlorella vulgaris, chlorella ... | 1998 | 9589070 |
| differentiation of rhizomucor species by carbon source utilization and isoenzyme analysis. | nineteen rhizomucor miehei and rhizomucor pusillus isolates were assayed for their ability to utilize 87 various substrates as a single carbon source. besides a difference in sucrose utilization, distinctive differences were found in the utilization of glycine, phenylalanine, and beta-alanine. five isoenzyme systems also proved useful for the determination of markers of distinctive value at a species level. data were used to obtain information about the genetic polymorphism of these species: a h ... | 1998 | 9650990 |
| conformational change in the activation of lipase: an analysis in terms of low-frequency normal modes. | the interfacial activation of rhizomucor miehei lipase (rml) involves the motion of an alpha-helical region (residues 82-96) which acts as a "lid" over the active site of the enzyme, undergoing a displacement from a "closed" to an "open" conformation upon binding of substrate. normal mode analyses performed in both low and high dielectric media reveal that low-frequency vibrational modes contribute significantly to the conformational transition between the closed and open conformations. in these ... | 1998 | 9655340 |
| anatomy of lipase binding sites: the scissile fatty acid binding site. | shape and physico-chemical properties of the scissile fatty acid binding sites of six lipases and two serine esterases were analyzed and compared in order to understand the molecular basis of substrate specificity. all eight serine esterases and lipases have similar architecture and catalytic mechanism of ester hydrolysis, but different substrate specificities for the acyl moiety. lipases and esterases differ in the geometry of their binding sites, lipases have a large, hydrophobic scissile fatt ... | 1998 | 9720251 |
| 1h-nmr on line monitoring of water activity during lipase catalysed esterification. | 1h-nmr spectroscopy is used to determine simultaneously the water activity (aw) and the time course of an esterification reaction catalysed by a lipase. chemical shifts signals of hydroxylic hydrogens in fast exchange (i.e the average hydroxylic signal of acid, alcohol and water) varies with water activity and ester content. calibration curves have been established from model media composed of the substrates and various ester contents, at different water activities, in order to mimic a reaction ... | 1998 | 9748540 |
| lipase specificity toward some acetylenic and olefinic alcohols in the esterification of pentanoic and stearic acids. | the esterification of five medium- and long-chain acetylenic alcohols (2-nonyn-1-ol, 10-undecyn-1-ol, 6-octadecyn-1-ol, 9-octadecyn-1-ol, and 13-docosyn-1-ol), seven olefinic alcohols (cis-3-nonen-1-ol, 10-undecen-1-ol, cis-6-octadecen-1-ol, cis-9-octadecen-1-ol, trans-9-octadecen-1-ol, trans-9, trans-11-octadecadien-1-ol, cis-9,cis-12-octadecadien-1-ol), and four short-chain unsaturated alcohols (allyl alcohol, 3-butyn-1-ol, 3-pentyn-1-ol, and cis-2-penten-1-ol) with pentanoic or stearic acid i ... | 1998 | 9778133 |
| simple conformation space search protocols for the evaluation of enantioselectivity of lipases. | two computational protocols have been evaluated regarding their ability to reproduce the enthalpic part of lipase enantioselectivity by forcefield potential energy differences (deltav#r-s). though the shortcomings of the approach are numerous, good qualitative results have been obtained here and elsewhere. the anticipated improvement of quantitative results by use of a second protocol, which did not impose any atom movement restrictions on the total system, was realized only in part. seemingly, ... | 1998 | 9930664 |
| structure of the rhizomucor miehei aspartic proteinase complexed with the inhibitor pepstatin a at 2.7 a resolution. | crystals of rhizomucor miehei aspartic proteinase (rmp) complexed with pepstatin a grew in the orthorhombic space group p212121 and were isomorphous to native rmp crystals. the unit-cell dimensions are a = 41.52, b = 50.82, c = 172.71 a. there is one rmp-pepstatin a complex per asymmetric unit. the structure of the rmp-pepstatin a complex has been refined to a crystallographic r value of 19.3% and an rfree value of 28.0% at 2.7 a resolution. a pepstatin a molecule fits into the large substrate-b ... | 1999 | 10089458 |
| effect of salt hydrate pair on lipase-catalyzed regioselective monoacylation of sucrose. | sucrose monoesters of a fatty acid were synthesized by using lipase in a solvent-free system. when lipase from mucor miehei was used as a catalyst with capric acid as the donor and sugar as the acceptor, sucrose 6-monocaprate was predominantly produced in a yield of 25.3%. the yield of product was significantly increased by the direct addition of a suitable pair of solid salt hydrates to the reaction mixture to control the water activity (aw). among the salt hydrate pairs investigated, the bariu ... | 1998 | 10099186 |
| 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 |
| regioselective synthesis of ethoxylated glycoside esters using beta-glucosidase in supersaturated solutions and lipases in organic solvents | three ethoxylated glycosides, tetraethylene glycol beta-d-glucoside, tetraethylene glycol beta-d-xyloside, and methoxy triethyleneglycol beta-d-glucoside, were prepared via almond beta-glucoside-catalyzed (trans)glycosylation carried out in supersaturated solutions of glucose or p-nitrophenyl beta-d-xyloside and the respective polyethylene glycols. the products were isolated and further modified by enzymatic esterification with candida antarctica and mucor miehei lipases. the latter enzyme showe ... | 1998 | 10099395 |
| analysis of the dynamics of rhizomucor miehei lipase at different temperatures. | the dynamics of rhizomucor miehei lipase has been studied by molecular dynamics simulations at temperatures ranging from 200-500k. simulations carried out in periodic boundary conditions and using explicit water molecules were performed for 400 ps at each temperature. our results indicate that conformational changes and internal motions in the protein are significantly influenced by the temperature increase. with increasing temperature, the number of internal hydrogen bonds decreases, while surf ... | 1999 | 10333171 |