A New Method for Spectrophotometric Assay of Activity of Cross-Linked Penicillin Acylase Aggregates

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N. A. Pchelintsev, M. I. Youshko, and V. K. Svedas^*

Belozersky Institute of Physico-Chemical Biology, Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (7-495) 939-2355; E-mail: vytas@belozersky.msu.ru

^* To whom correspondence should be addressed.

Received April 4, 2005; Revision received May 12, 2005

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A new method for monitoring reactions catalyzed by an immobilized enzyme, cross-linked penicillin acylase aggregates (PA CLEA), is suggested. Appropriate chromogenic substrates for spectrophotometric assay of catalytic activity of immobilized enzyme were chosen and their kinetic parameters determined. Active sites in PA CLEA preparations were titrated by the suggested method; it is shown that almost all active sites are retained during immobilization. This method is characterized as highly expressive, simple, and precise and may be used for control of PA immobilization efficiency as well as for study of operational, thermal, and pH stability of immobilized enzyme preparations.

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KEY WORDS: cross-linked enzyme aggregates, penicillin acylase, activity assay method, chromogenic substrates

DOI: 10.1134/S0006297906030126

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