Functional Stabilization of Trypsin by Conjugation with b-Cyclodextrin-Modified Carboxymethylcellulose Marı ´a L. Villalonga, 1 Michael Ferna ´ndez, 1 Alex Fragoso, 2 Roberto Cao, 2 and Reynaldo Villalonga 1, * 1 Enzyme Technology Group, Center for Biotechnological Studies, University of Matanzas, Matanzas, Cuba 2 Laboratory of Bioinorganic Chemistry, Faculty of Chemistry, Havana University, Havana, Cuba ABSTRACT Bovine pancreatic trypsin was chemically modified by a b-cyclodex- trin-carboxymethylcellulose polymer using 1-ethyl-3-(3-dimethyl- aminopropyl) carbodiimide as coupling agent. The conjugate retained 110% and 95% of the initial esterolytic and proteolytic activ- ity, respectively, and contained about 2 mol of polymer per mol of trypsin. The optimum temperature for trypsin was increased in 8  C after conjugation. The thermostability of the enzyme was increased in a bout 16  C after modification. The conjugate prepared was also *Correspondence: Reynaldo Villalonga, Enzyme Technology Group, Center for Biotechnological Studies, University of Matanzas, Autopista a Varadero km 3 1 2 Matanzas, C.P. 44740, Cuba; E-mail: reynaldo.villalonga@umcc.cu. PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY Vol. 33, No. 1, pp. 53–66, 2003 53 DOI: 10.1081/PB-120018369 1082-6068 (Print); 1532-2297 (Online) Copyright # 2003 by Marcel Dekker, Inc. www.dekker.com