Partial purification of milk-clotting and caseinase enzymes, produced by Absidia cylindrospora, and isolation of rennin-like enzyme
1987; Gustav Fischer Verlag; Volume: 142; Issue: 1 Linguagem: Inglês
10.1016/s0232-4393(87)80072-0
ISSN0232-4393
AutoresA. M. Ismail, Samy A. El‐Aassar, Ahmed F. Abdel‐Fattah,
Tópico(s)Protein Hydrolysis and Bioactive Peptides
ResumoPartial purification of milk-clotting and caseinase enzymes, produced by Absidia cylindrospora, was achieved by fractional precipitation with ammonium sulphate, acetone, and ethanol. The fractions precipitated at 25 % ammonium sulphate saturation, 33.3 % acetone, and 85 % ethanol possessed only proteolytic activity. Acetone fractionation was characterized by being the most effective in eliminating most of the recovered proteolytic activity in the 50 % fraction. Of the 15 fractions obtained by the three precipitants, the 75 % acetone fraction was the most promising enzyme fraction, possessing rennin properties. That fraction possessed the highest milk-clotting activity/proteolytic activity ratio (173.8), which reached about 5.7-fold that of the culture filtrate. Durch eine fraktionierte Ausfällung mit Ammoniumsulfat, Azeton und Ethanol gelang eine teilweise Reinigung von Milchgerinnungs-und Caseinase-Enzymen, die durch Absidia cylindrospora gebildet wurden. Die durch eine 25 %ige Ammoniumsulfat-, eine 33,3 %ige Azeton- und eine 85 %-ige Ethanol-Sättigung erzielten Präzipitate waren nur proteolytisch wirksam. Eine 75%ige Azeton-Sättigung erfaßte die meisten Enzyme mit Rennin-ähnlichen Eigenschaften. Das Verhältnis Milchgerinnungs-/proteolytischen Enzymen lag hier mit 173,8 am höchsten.
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