Amidase chymotrypsin

Enzymes such as proteases (122), subtilisin (123), acylases, peptidases, amidases, and lipases (124) are reported to catalyze amide bond formation with, in some cases, enantiospeciflcity of over 99%. Despite limited enzyme-substrate compatibility, specific conditions have been developed to reverse their natural reactivity, which is in favor of the hydrolysis. For example, Kyotorphin (Tyr-Arg) (125), a potent analgesic, was produced on an industrial scale using a-chymotrypsin, a peptidase isolated from bovine pancreas. 

As one might expect, water has a dramatic effect on enzyme stability in SCFs. Lozano et al. found that the half-life time of a-chymotrypsin decreased exponentially in SCCO2 with increasing water content from 0 to 15 wt% [28]. Kashe et al. found that a-chymotrypsin, trypsin and penicillin amidase partially unfolded during pressure reduction in humid SCCO2. They suggested that... 

Figure 4 shows the temperature profiles for amidase activity of the protease from M. jannaschii at 10,250, and 500 atm. The optimum temperature for activity of 116° at low pressure (10 atm) is one of the highest optimum temperatures for a proteolytic enzyme reported in the literature. Figure 4 also shows that pressure substantially enhances the activity of the protease at each temperature for example, application of 500 atm increases the maximum reaction rate about twofold and the rate at 130°C fivefold. The 400% enhancement of amidase activity at 130° translates to an overall activation volume, A V, of — 106 ml mol , as determined by the Johnson-Eyring equation [Eq. (2)]. The most negative activation volumes previously reported for serine proteases were —36 ml mol for the digestion of casein by trypsin and —33 ml mol for the hydrolysis of Suc-Ala-Ala-pNA by a-chymotrypsin. Michels and Clark also found that the protease is stabilized... 

DEAE-cellulose has been used to prepare active immobilized derivatives of chymotrypsin, lactate dehydrogenase, alcohol dehydrogenase, penicillin amidase, and glucoamylase, and water-soluble conjugates with gluco-amylase. The adsorption is presumed to be of an ionic nature. 

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