Aspergillus protease

Kamat et al. found a pressure effect on the stereoselectivity of transesterifications in supercritical fluoroform [64]. The stereoselectivity of subtilisin Carlsberg and Aspergillus proteases increased, while the activity decreased with increasing fluoroform pressure from 66 to 352 bar. They conclude that the stereoselectivity of these proteases increases because fluoroform becomes more hydrophilic as the pressure rises. This finding is in accordance with a previously presented hypothesis for substrate binding in enzymes. 

The Bacillus and Aspergillus protease hydrolysates of as-casein were fractionated by gel electrophoresis. Each fraction was further characterized by separation on a C g column (A = 220nm). A 60-min 100/0—> 30/70 (at 55min)—> 9/91 water (0.06% TFA)/methanol gradient was used. This method readily differentiated the protease hydrolysates as well as the fractions within each hydrolysate. 

MatsusTTlma, K. (1958). On the naturally occurring Inhibitors for Aspergillus protease. III. Ovo-Inhibitor. Nippon Nogel kagaku KaTshI 32, 211-215. 

Pectinase, protease Aspergillus niger, A. aureus Clarifying agents in fruit juice... 

In all the reported examples, the enzyme selectivity was affected by the solvent used, but the stereochemical preference remained the same. However, in some specific cases it was found that it was also possible to invert the hydrolases enantioselectivity. The first report was again from iQibanov s group, which described the transesterification of the model compound (13) with n-propanol. As shown in Table 1.6, the enantiopreference of an Aspergillus oryzae protease shifted from the (l)- to the (D)-enantiomer by moving from acetonitrile to CCI4 [30]. Similar observations on the inversion of enantioselectivity by switching from one solvent to another were later reported by other authors [31]. 

Biocatalysis has emerged as an important tool for the enantioselective synthesis of chiral pharmaceutical intermediates and several review articles have been published in recent years [133-137]. For example, quinuclidinol is a common pharmacophore of neuromodulators acting on muscarinic receptors (Figure 6.50). (JJ)-Quinudidin-3-ol was prepared via Aspergillus melleus protease-mediated enantioselective hydrolysis of the racemic butyrate [54,138]. Calcium hydroxide served as a scavenger of butyric acid to prevent enzyme inhibition and the unwanted (R) enantiomer was racemized over Raney Co under hydrogen for recycling. 

In the parental strain enzymatic activity reached the maximum value at 96 h. The hybrids H5, H15 and HIO showed good activity compared to Aspergillus sp. CH-Y-1043. Also, a difference with respect to parental strain was detected, a slight drop of activity in hybrids at 120 h. This effect was not due to changes of the pH during fermentation because it was similar in all cultures. The causes of this response in hybrids are unknown. More experiments for to evaluate the presence of proteases in the culture medium should be performed. Table 3 presents the data of the higher levels of endopectinases produced by... 

Following Mosher s report, several publications appeared showing the preparation of Mosher s acid. One example is the chemoenzymatic preparation of Mosher s acid using Aspergillus oryzae protease (Scheme 1-5)24 ... 

Aspergillus oryzae protease Scheme 1-5. Chemoenzymatic preparation of Mosher s acid. 

Moser, M., Menz, G., Blaser, K., and Crameri, R. (1994). Recombinant expression and antigenic properties of a 32-kilodalton extracellular alkaline protease, representing a possible virulence factor from Aspergillus fumigatus. Infect. Immun. 62, 936-942. 

Enz5mies Proteases Amylases Cellulases Various Bacilli, e.g. Bacillus licheniformis Bacillus subtilis, Aspergillus oryzae Trichoderma viride, Penicillium pinophilum... 

Polyethylene glycol) Protease (Aspergillus oryzae) Pyridine 8 35... 

For the preparation of the (S)-enantiomer an enzymatic racemic resolution process using Aspergillus oryzae protease was developed by Sepracor ... 

Epoxy groups, such as that of E-64, a compound isolated from the culture medium of a species of Aspergillus, react irreversibly with the active site thiolate group of cysteine proteases.1/U/V Related epoxides may become useful medications against abnormal cathepsin levels. 

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