Immobilized pronase

The higher rate of hydrolysis by immobilized pronase also indicates a less stable structure (Swaisgood 1982). 

The first total synthesis of amiclenomycin, an inhibitor of biotin biosynthesis, was completed by A. Marquet and co-workers. In order to prove its structure unambiguously, both the cis and trans isomers were prepared. The L-amino acid functionality was installed by a Strecker reaction using TMSCN in the presence of catalytic amounts of Znla. The resulting O-TMS protected cyanohydrin was exposed to saturated methanolic ammonia solution, which gave rise to the corresponding a-amino nitrile. Enzymatic hydrolysis with immobilized pronase afforded the desired L-amino acid. 

Aspartame has been assayed by a flow injection analysis biosensor employing an immobilized enzyme (pronase) which cleaves the peptide bond. The resulting phenylalanine methyl ester is then detected by an L-amino acid oxidase electrode. This method was applied to analysis of aspartame in foods [82]. 

Kato et al. [54,55] reported using the proteases papain, pronase E, and chymotrypsin for the deamidation of food proteins, and Kato et al. [56] later reported deamidation of selected plant and animal proteins with chymotrypsin immobilized on controlled pore glass. The reactions were carried out at alkaline pH (pH 10) and 20°C and resulted in 5 to 20% deamidation with up to 8% peptide bond hydrolysis. Functional properties of proteins thus deamidated showed increased solubility and emulsifying and foaming properties. Enzymatic... 

After immobihzation, the resistance toward protease increases. The reason may be an increase of steric access hindrance to the immobilized protease due to the three-dimensional obstacles of the carrier. If we take aminoacylase for example, under the action of trypsin, the activity of the solution enzyme was only 23%, the activity of the enzyme immobilized by DEAE-cellulose was 33% and the activity of the enzyme immobilized by DEAE-dextran was 87%. Under the action of protease, Pronase P, the activity of the solution enzyme, the enzyme immobilized by DEAE-ceUulose and the enzyme immobilized by DEAE-dextran was 48%, 53%, 88%, respectively. Immobilized protease can generally avoid digestion damaging itself. 

Chitin has been used as a matrix for the covalent immobilization of enzymes for example, jS-o-galactosidases, chymotrypsin, and acid phosphatase were attached to chitin via glutaraldehyde. Pretreatment of chitin with acid, base, ammonia, or pronase was compared with regard to the release of titratable amino-groups and the ability of the polysaccharide to retain /S-D-galactosidase activity. 

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