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At least 19 recordsLinked to original sources
PubMed1977

N-terminal amino acid sequences of acid proteases: acid proteases from Penicillium roqueforti and Rhizopus chinensis and alignment with penicillopepsin and mammalian proteases.

The amino-terminal sequence (33 residues) of the acid protease from Penicillium roqueforti has been determined with an automated sequencer. The amino-terminal sequence of Rhizopus pepsin (published by Sepulveda, P., Jackson, K. W. & Tang, J. (1975) Biochem. Biophys. Res. Commun. 63, 1106-1112) has been extended from 27 residues to 39 residues. Also, it was found that two forms of Rhizopus pepsin differ in position 15, where Rhizopus pepsin I has an isoleucine and Rhizopus pepsin II a valine residue. The new sequences have been aligned with the amino-terminal sequences of penicillopepsin (EC 3.4.23.7), pig pepsin (EC 3.4.23.1), calf chymosin (EC 3.4.23.4), human pepsin (EC 3.4.23.2), human gastricsin (EC 3.4.23.3), and cow pepsin (EC 3.4.23.1). Residues 31-35 (numbering based on pig pepsin, Tang, J., Sepulveda, P., Marciniszyn, Jr., J., Chen, K.S.C., Huang, W.-Y. , Tao, N., Liu, D. & Lanier, P. (1973) Proc. Natl. Acad. Sci. U.S.A. 70, 3437-3739) are identical in all enzymes. This section contains one of the two aspartic acids (Asp-32) implicated in the active site. The similarity of the sequences provides strong evidence for the homology of these acid proteases.

Amines↗
PubMed1979

Rhizopus osteomyelitis. A case report and review.

Mucormycosis osteomyelitis has previously been described exclusively in association with contiguous infections of rhinocerebral mucormycosis. In a patient with corticosteroid-dependent neutropenia and anemia osteomyelitis of the femur developed caused by the Mucoraceae Rhizopus. Although a primary focus was not identified, we believe this infection was hematogenous in origin. Mitogen stimulation to phytohemagglutinin (PHA) of the patient's lymphocytes revealed depressed cellullar immunity; however, there was specific response to Rhizopus extract. Treatment with systemic amphotericin B prevented further progression of the infection. A review of mucormycosis osteomyelitis is presented.

Adolescent↗
PubMed1975

Purification and some enzymatic properties of the chitosanase from Bacillus R-4 which lyses Rhizopus cell walls.

A strain of Bacillus sp (Bacillus R-4) produces a protease and a carbohydrolase both of which have the ability to lyse Rhizopus cell walls. Of the enzymes, the carbohydrolase has been purified to an ultracentrifugally and electrophoretically homogeneous state, and identified as a chitosanase. The enzyme was active on glycol chitosan as well as chitosan. Molecular weight of the purified enzyme was estimated as 31 000 and isoelectric point as pH 8.30. The enzyme was most active at pH 5.6 and at 40 degrees C with either Rhizopus cell wall or glycol chitosan as substrate, and was stable over a range of pH 4.5 to 7.5 at 40 degrees C for 3 h. The activity was lost by sulfhydryl reagents and restored by either reduced glutathione of L-cysteine. An abrupt decrease in viscosity of the reaction mixture suggested an endowise cleavage of chitosan by this enzyme.

Bacillus↗
PubMed1975

Fluorescence studies on the active sites of porcine pepsin and Rhizopus-pepsin.

Fluorescence studies on the interaction, with porcine pepsin, of oligopeptides bearing a mansyl (Mns, 6-(N-methylanilino)-2-naphthalenesulfonyl) or dansyl (Dns, 5-dimethylaminonaphthalene-1-sulfonyl) group at the NH2 or COOH terminus have provided further evidence showing that the probe group is drawn into the extended active site largely as a consequence of the specific binding of the peptide portion of the substrate. The active site does not appear to have appreciable intrinsic affinity for the mansyl or dansyl group, and the principal contribution to the specific peptide-protein interaction is provided by the sensitive L-phenylalanyl-L-phenylalanyl (Phe-Phe) unit of the substrates tested. The pepsin inhibitor pepstatin can displace substrates such as Mns-(Gly)n-Phe-Phe-OR or Gly-Gly-Phe-Phe-NHNH-Mns from the active site of porcine pepsin; in these circumstances the mansyl group is bound weakly at a separate, nonspecific locus, distinct from the active site, which can accept the mansyl group of Mns-Gly-Gly-OR or mansylamide. In the interaction with substrates such as Mns-(Gly)n-Phe-Phe-OR or Dns-(Gly)n-Phe-Phe-OR, the above conclusions for porcine pepsin also apply to Rhizopus-pepsin. With substrates such as Gly-Gly-Phe-Phe-NHNH-Mns, however, the active site of Rhizopus-pepsin shows less affinity for the fluorescent probe group than does that of porcine pepsin, suggesting structural differences between the two acid proteinases in the region of their extended active sites which bind the COOH-terminal portion of small oligopeptide substrates.

Anilino Naphthalenesulfonates↗
PubMedDate not supplied

[Extracellular lipases of the fungus Rhizopus microsporus UzLT-1].

Lipase biosynthesis by the fungus Rhizopus microsporus UzLT-1 was investigated. Under certain conditions the fungus could produce two forms of extracellular lipases. The paper describes the process of purification of the enzyme L-I,N- and C-terminal amino acids of the lipases have been determined. Identity of terminal amino acids of both enzymes has been demonstrated. It has been shown that both forms of lipase from Rhizopus microporus hydrolyze predominantly alpha-ester bonds.

Amino Acids↗
PubMed1979

Cutaneous Rhizopus infection. Occurrence as a postoperative complication associated with an elasticized adhesive dressing.

A 29-year-0ld woman in good health except for scoliosis suffered severe sequelae during the postoperative course for placement of a Harrington rod. A cutaneous Rhizopus infection in and about the incision site was attributed to the use of a contaminated elasticized adhesive (Elastoplast) dressing. The comtamination was established as a nosocomial problem, which is extremely difficult to control. The extent of the infection, subsequent long recovery course, and remarkable sequelae make this case unusual.

Adult↗
PubMed1977

The crystal structure of an acid protease from Rhizopus chinensis at 2.5 A resolution.

This paper contains a preliminary report of the crystal structure of the acid protease from Rhizopus chinensis at 2.5 A resolution. The molecule is bilobal with a large cleft between the lobes. Pepstatin binds in the cleft near the catalytically active Asp-35. The overall folding of the molecule consists primarily of antiparallel beta-strands, there being only four small helices.

Binding Sites↗
PubMed1978

alpha-Mannosidases of genera Aspergillus and Rhizopus. Activity and capacity to utilize Saccharomyces cerevisiae mannan of the best alpha-mannosidase producer Aspergillus flavus Link 69.

Strains of fungi imperfecti of genera Aspergillus and Rhizopus were tested for the ability to produce alpha-mannosidases. The most suitable alpha-mannosidase producer of a total of 20 strains under study was Aspergillus Ravus Link 69. The parameters studied during the cultivation included the growth rate expressed as cell dry weight, alpha-mannosidase activity of the extracellular medium with p-nitorphenyl alpha-D-mannopyranoside as substrate, and utilization of Saccharomyces cerebisiae mannan via its disappearance from the cultivation medium.

Aspergillus↗
PubMed1978

Purification, characterization, and action-pattern studies on the endo-(1 linked to 3)-beta-D-glucanase from Rhizopus arrhizus QM 1032.

The extracellular (1 linked to 3)-beta-D-glucanase [(1 linked to 3)-beta-D-glucan glucanohydrolase, EC 3.2.1.6] produced by Rhizopus arrhizus QU 1032 was purified 305-fold in 70% overall yield. This preparation was found to be homogeneous by ultracentrifugation (sedimentation velocity and equilibrium studies), electrophoresis on acrylamide gel with normal, sodium dodecyl sulfate, and urea-acetic acid gels, and upon isoelectric focusing. The amino acid composition of the enzyme has been determined and it possesses a carbohydrate moiety compose of mannose and galactose (in the ratio approximately 5:1) that is linked to the protein through a 2-acetamido-2-deoxyglucose residue. The molecular weight, as determined by equilibrium sedimentation, is 28,800 and this number was confirmed by electrophoresis on gels of sodium dodecyl sulfate. The enzyme does not possess subunit structure. It hydrolyzes its substrates with retention of configuration and possesses transglycosylating ability. The rates of hydrolysis of a wide variety of substrates were determined, and its action pattern on a series of oligosaccharides containing mixed (1 linked to 3)-, (1 linked to 4)-, and (1 linked to 6)-beta-D-glucopyranosyl residues was investigated. The enzyme favors stretches of beta-D-(1 linked to 3) linkages, but it can hydrolyze beta-D-(1 linked to 4) linkages that are flanked on the non-reducing side with stretches of beta-D-(1 linked to 3) links. The enzyme will not act on (1 linked to 6)-beta-D-glucosyl linkages located in stretches of beta-D-(1 linked to 3) and will not act on (1 linked to 3) beta-D-glycosidic linkages involving sugars other than D-glucose.

Glucan Endo-1,3-beta-D-Glucosidase↗
PubMed1978

Granulomatous mediastinitis due to rhizopus species.

Phycomycosis is seen most frequently in association with states of immunologic disturbance or hormonal imbalance. Several characteristic sites of infection with Phycomycetes are recognized, but mediastinal involvement has not been previously reported. A case of mediastinal granuloma due to Rhizopus species is described, and comparisons are made with other infections of similar histologic appearance.

Adult↗
PubMed1975

Free fatty acids identified as antitryptic factor in soybeans fermented by Rhizopus oligosporus.

The trypsin-inhibitory activity observed in cooked soybeans fermented by Rhizopus oligosporus (fungus used in tempeh fermentation) has been examined. The active compounds have now been isolated by ethanol extraction and thin-layer chromatography and have been identified as free fatty acids by infrared spectroscopy and gas-liquid chromatography. Oleic, lineoleic, and linolenic acids are primarily responsible for the increased trypsin-inhibiting activity of cooked soybeans after fermentation. The free fatty acids are liberated from oil in the soybeans by fungal lipase, and they differ from other reported soybean trypsin inhibitors that are protein in nature. Free fatty acids have been previously reported to inhibit various enzymes, such as glycolytic, glyconeogenic, lipogenic, and also proteolytic. Their effect appears to be a nonspecific type of inhibition. Further studies are required to determine their physiological relevance, if any.

Cooking↗
PubMed1976

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, however, was brought about by modifying the two less reactive residues, and the modification of these residues was prevented by the substrates. The characteristic difference spectrum produced by maltose (7) disappeared in parallel with the loss of the catalytic activity. These results suggest that the tryptophan residue(s) responsible for the maltose-induced difference spectrum may be located at one of the subsite near the catalytic site and plays an important role in the catalytic activity of the enzyme.

Binding Sites↗
PubMed1976

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-glucoside bind mainly to Subsites 1 and 2, respectively. The inhibitor constant of gluconolatone was determined to be 1.5 mM, which is in good agreement with the dissociation constant estimated by difference spectrophotometry (1.5 mM) (Ohnishi, M, et al. (1975) J. Biochem, 77, 695-703).

Amylases↗
PubMed1977

Amino acid sequences around 1, 2-epoxy-3-(p-nitrophenoxy)propane-reactive residues in rhizopus chinensis acid protease: homology with pepsin and rennin.

Two different peptides containing an aspartyl residue reactive with 1, 2-epoxy-3-(p-nitrophenoxy)propane (EPNP) in the acid protease from Rhizopus chinensis were isolated from a peptic digest of the EPNP-modified enzyme. One of the peptides was sequenced as Asp-Thr-Gly-Ser-Asp. The amino acid sequence had very high homology with those around the EPNP-reactive aspartyl residues in rennin (chymosin) [EC 3.4.23.4] and pepsin [EC 3.4.23.1]. The other peptide contained no methionine residue and gave the sequence: Asp-Thr-Gly-Thr-Thr-Leu. The N-terminal aspartyl residue of each peptide was deduced to be the EPNP-reactive site.

Amino Acid Sequence↗
PubMed1978

Purification and some properties of three forms of glucoamylase from a Rhizopus species.

1. Three forms of glucoamylase [EC 3.2.1.3] were simultaneously purified from a Rhizopus species by (NH4)2SO4 fractionation and successive chromatographies on Sephadex G-75, DEAE-Sephadex, and CM-Sephadex, and were finally separated from each other by means of recycling chromatography on Bio-Gel P-150. The purification achieved was 3--4 fold from crude extract with respect to each glucoamylase; the yields of the three glucoamylases, designated as Gluc1, Gluc2, and Gluc3 in order of content, were 39, 7, and 0.4%, respectively. All the purified enzymes were homogeneous in polyacrylamide gel electrophoresis, isoelectric focusing, and ultracentrifugation. 2. The three glucoamylases were glycoproteins differing in both amino acid composition and carbohydrate content, but showed a common antigenicity in immunodiffusion. The molecular weights of Gluc1, Gluc2, and Gluc3 were estimated to be 74,000, 58,600, and 61,400, respectively, by sedimentation equilibrium and these values were verified by SDS-polyacrylamide gel electrophoresis. The specific activities of the three enzymes toward starch were in the opposite order to their molecular weights. 3. The three glucoamylases had the same broad pH optima in the range pH 4.5--5.0 and shared a common susceptibility to inactivation by heat, extreme pH, and such divalent cations as Hg2+, Pb2+, and Mn2+, indicating close similarity in enzymatic properties.

Amino Acids↗
PubMed1979

Alcohol dehydrogenase from Rhizopus javanicus.

Alcohol dehydrogenase of Rhizopus javanicus was purified, and its physical and chemical characteristics were determined. The intact enzyme was shown to have a molecular weight of approximately 60,000. Since the smallest apparent subunit was 14,000, the enzyme was presumed to be composed of four subunits. The crude mycelial extract contained multiple forms of the enzyme, which were separated by ion-exchange chromatography.

Alcohol Oxidoreductases↗
PubMed1975

Kynureninase-Type enzymes of Penicillum roqueforti, Aspergillus niger, Rhizopus stolonifer, and Pseudomonas fluorescens: further evidence for distinct kynureninase and hydroxykynureninase activities.

The kynureninase-type enzymes of three fungi and one bacterium were isolated and examined kinetically for their ability to catalyze the hydrolysis of L-kynurenine and L-3-hydroxykynurenine. The phycomycete Rhizopus stolonifer was found to contain a single, constitutive enzyme with Km for L-3-hydroxykynurenine and L-kynurenine of 6.67 times 10-minus 6 and 2.5 times 10-minus 4 M, respectively. The ascomycetes Aspergillus niger and Penicillium roqueforti each contain an enzyme, induced by L-tryptophan, with similar Km for L-3-hydroxykynurenine and L-kynurenine ranging from 5.9 times 10-minus 5 to 14.3 times 10-minus 5 M, as well as a constitutive enzyme with Km for the two substrates of similar to 4 times 10-minus 6 M and 10-minus 4 M. The bacterium Pseudomonas fluorescens has a single, inducible enzyme with Km for L-3-hydroxykynurenine and L-kynurenine of 5 times 10-minus 4 and 7 times 10-minus 5 M. In addition, significant differences in maximal velocities (Vmax) were observed in two cases. The Vmax of the inducible activity from P. fluorescens was 4.5 times greater for L-kynurenine than L-3-hydroxykynurenine, whereas the Vmax of the constitutive activity from R. stolonifer was 2.5 times greater for L-3-hydroxykynurenine. It is concluded (i) that the constitutive activities are hydroxykynureninases involved in the biosynthesis of nicotinamide adenine dinucleotide from L-tryptophan, (ii) that the inducible activities are kynureninases involved in the catabolism of L-tryptophan to anthranilate, and (iii) that R. stolonifer and P. fluorescens, respectively, carry the most specific examples of each type of enzyme.

Ammonium Sulfate↗