Inactivation of Acid Proteases from Rhizopus chinensis, Aspergillus saitoi and Mucor pusillus, and Calf Rennin by Diazoacetylnorleucine Methyl Ester*

Diazo Compounds: Versatile Tools for Chemical Biology

“…145 Using these techniques, novel acid proteases were classified based on their propensity to be inactivated by a diazo compound. 146–152 Nonetheless, with the advent of site-directed mutagenesis, the use of diazo compounds to characterize proteins became rare.…”

Enzyme Technology

“…The enzyme has been partially purified from A. turbidans ATCC 9325 and displayed a strong ester hydrolase activity with IX-amino acid esters only. The Km for cephalexin deacylation was 2.99 mM (Takahashi et al 1972;. The enzyme also displayed IX-amino-acyltransferase activity in the presence of suitable acyl receptors such as 7-ADCA to produce cephalexin .…”

“…R. chinensis was cultured for 70 hrs at 25°C on wheat bran for protease production (Fukumoto et aL 1967). (Graham et al 1973;Mizobe et al 1973;Nakamura 1977Nakamura , 1978Sepulveda et al 1975;Subramanian 1978;Subramanian et al 1977;Takahashi et aL 1972;Tsuru et al 1969). It belongs to the pepsin type, has a pH optimum between 2.9 and 3.2 and its temperature optimum at 60°C.…”

“…Bacterial enzymes which are able to synthesise cephalosporins, starting from 7-ACA or 7-ADCA and an sppropriate \i-amino acid ester have been described by Takahashi et al (1972Takahashi et al ( , 1973. Since the enzyme involved in these synthetic reactions utilises IX-amino acid esters as acyl donors and transfers these acyl groups to both water (hydrolysis) and 7-amino-cephem compounds or 6-APA (transfer), it has been named 'IX-amino acid ester hydrolase ( Figure 9).…”

Χημικη Τροποποιηση Της Καθεψινης D Με Διαιθυλοπυροκαρβονικο

“…(α) 'Εστεροποίηση_των_καρ3οξυλομάδων_τής_καθ Ή έστεροποίηση τών καρβοξυλομάδων πολλών όξινων πρωτεασών κατορθώ θηκε μέ τήν χρησιμοποίηση διαζωενώσεων. Τά ένζυμα αυτά είναι: ή όξινη πρωτεάση τοΰ θυρεοειδούς (Smith et al, 1969), οί όξινες πρωτεάσες τών μυκήτων Rhizopus Chinensis, Aspergillus Niger καί Mucor Pusillus (Takahashi et al, 1972) καί οί καθεψίνες D καί E (Keilova, 1970' Keilova & Lapresle, 1970' Ferguson et al, 1973' Rakitzis, 1974. Σέ δλες τίς περιπτώσεις πού κατορθώθηκε ή έστεροποίηση τών καρβοξυλίων της καθε ψίνης D, ή άλλων όξινων πρωτεασών, παρατηρήθηκε καί απώλεια τής ένζυμικής δραστικότητας.…”