Medline/PubMed Citation | Related Articles in PubMed | Download to Citation Manager

Biotechnology and Applied Biochemistry (2002) 36, (235–239) (Printed in Great Britain)

PDF

Legacy HTML

Stabilization of a-chymotrypsin by modification with b-cyclodextrin derivatives

Michael Fernández*, María de Lourdes Villalonga*, Alex Fragoso†, Roberto Cao† and Reynaldo Villalonga*¹

*Enzyme Technology Group, Center for Biotechnological Studies, University of Matanzas, Matanzas, C.P. 44740, Cuba, and †Laboratory of Bioinorganic Chemistry, Faculty of Chemistry, University of Havana, Havana 10400, Cuba

Key words: enzyme thermostabilization, neoglycoenzyme, serine protease, supramolecular interaction.

Abbreviations used: CD, cyclodextrin; aCD, a-cyclodextrin; bCD, b-cyclodextrin; gCD, g-cyclodextrin; CD1, mono-6-formyl-b-cyclodextrin; CD2, mono-6-succinyl-6-deoxy-b-cyclodextrin; ATEE, N-a-acetyl-L-tyrosine ethyl ester hydrochloride; EDAC, 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide.

¹To whom correspondence should be addressed (e-mail reynaldo.villalonga@umcc.cu).

Bovine pancreatic a-chymotrypsin was chemically modified with two different b-cyclodextrin derivatives, named mono-6-formyl-b-cyclodextrin and mono-6-succinyl-6-deoxy-b-cyclodextrin. The modified enzymes contained approx. 3–5 mol of oligosaccharide/mol of protein, and retained full proteolytic and esterolytic activity. The optimum temperature for a-chymotrypsin was increased by 8 °C and its thermostability was enhanced by about 4–6 °C after modification. The conjugated enzymes were also more resistant to thermal inactivation at temperatures ranging from 45 to 55 °C. Additionally, the modified enzymes were 7-fold more stable against incubation at pH 9.0. The possible influence of supramolecular interactions on the thermal stabilization of modified a-chymotrypsins was also studied.

Received 14 June 2002; accepted 23 July 2002

Portland Press Ltd © 2002