| proton magnetic resonance spectroscopy of an essential histidyl residue in a milk-clotting acid protease, mucor rennin. | the location and state of an essential histidyl residue in a milk-clotting acid proteases, mucor rennin, were investigated by nmr spectroscopy. assignment of the c2h resonance peak of the essential histidyl residue was possible by comparison of the nmr spectrum of the native enzyme with that of the photo-oxidized enzyme. the ph titration curve for the chemical shift of the c2h proton showed two inflections, a major one with pka = 7.4 and a minor one with pka = 3.5 at 30 degrees c. the major infl ... | 1982 | 6749830 |
| mycotoxins and mycoflora in animal feedstuffs in western canada. | feed samples associated with 51 cases of suspected or potential mycotoxicoses of farm animals in western canada were examined during a three year study. ochratoxin a was detected in four cases, t-2 toxin and diacetoxyscirpenol in one, and sterigmatocystin in one. samples examined for microflora associated with production of these mycotoxins contained penicillium spp., aspergillus ochraceus, fusarium spp. and fungi of the aspergillus glaucus group. samples were analyzed for t-2 toxin and diacetox ... | 1983 | 6831303 |
| preparation and some chemical characteristics of milk-clotting protease from bacillus mesentericus 76. | pure milk-clotting protease (mcp-76) is isolated by isotachophoresis at ph 5.0. the native molecule has only one protein chain. it is a metaloenzyme containing zinc. the pure mcp-76 has a molecular weight of 33 000 (+/- 1500) and by diphenyl-indenonyl-isothiocyanate method showed arginine as n-terminal amino acid. | 1981 | 7014483 |
| genetic transformation of a rhizomucor pusillus mutant defective in asparagine-linked glycosylation: production of a milk-clotting enzyme in a less-glycosylated form. | rhizomucor pusillus 1116r3 has a defect in alg2 encoding a mannosyltransferase in the asparagine (n)-linked oligosaccharide biosynthetic pathway and produces proteins in less-glycosylated forms. for development of a genetic transformation system for this zygomycete, an uracil auxotroph (mutant 1116u17) as the host strain was derived by ultraviolet (uv) mutagenesis as 5-fluoroorotic acid-resistant colonies and the orotidine-5'-monophosphate (omp) decarboxylase (pyr4) gene as a selection marker wa ... | 1999 | 10531653 |
| isolation of milk-clotting enzyme from transgenic sheep milk and its comparison with calf chymosin. | technology for preparation of chymosin from milk of transgenic sheep has been elaborated. purification of the preparation by ion-exchange chromatography on aminosilochrom and biospecific chromatography on bacitracin-sepharose yielded homogeneous active enzyme. hydrolysis of protein substrates (hemoglobin, bsa, and sodium caseinate) by the transgenic sheep chymosin and stability of the enzyme at various values of ph were studied. judging by the amino acid composition, the n-terminal sequence invo ... | 2001 | 11403643 |
| ochratoxin a in airborne dust and fungal conidia. | farm workers are often exposed to high concentrations of airborne organic dust and fungal conidia, especially when working with plant materials. the purpose of this investigation was to study the possibility of exposure to the mycotoxin ochratoxin a (ota) through inhalation of organic dust and conidia. dust and aerosol samples were collected from three local cowsheds. aerosol samples for determination of total conidia and dust concentrations were collected by stationary sampling on polycarbonate ... | 2001 | 11554583 |