Interaction between pullulanase from Klebsiella pneumoniae and cyclodextrins

• Published in: Journal of biochemistry (Tokyo) 1993, Vol.113 (1), p.93-96
• Main Authors: Iwamoto, H, Ohmori, M, Ohno, M, Hirose, J, Hiromi, K, Fukada, H, Takahashi, K, Hashimoto, H, Sakai, S
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Calorimetry; Cyclodextrins - metabolism; Cyclodextrins - pharmacology; dextrins; enzyme activity; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Glycoside Hydrolases - antagonists & inhibitors; Glycoside Hydrolases - metabolism; Hydrolases; inhibition; interactions; Kinetics; Klebsiella pneumoniae; Klebsiella pneumoniae - enzymology; pullulanase; Spectrophotometry, Ultraviolet
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a124010

The interaction between pullulanase from Klebsiella pneumoniae and alpha-, beta-, and gamma-cyclodextrins and 6-O-alpha-glucosyl-alpha-cyclodextrin and 6-O-alpha-glucosyl-beta-cyclodextrin was examined by means of inhibition studies of the enzyme activity, UV difference spectroscopy, and flow calorimetry. All the above cyclodextrins were found to be competitive inhibitors, but beta-cyclodextrin and 6-O-alpha-glucosyl-beta-cyclodextrin showed strong inhibition, the inhibitor constants being two orders of magnitude less than those of alpha- and gamma-cyclodextrins. The difference spectra of beta-cyclodextrin were slightly but significantly different from those of the other cyclodextrins, showing blue shift of a few nanometers. Moreover, only beta-cyclodextrin has a positive entropy change upon binding with the enzyme; all the other cyclodextrins have negative values. These results show that the binding mode of beta-cyclodextrin is subtly different from those of alpha- and gamma-cyclodextrins.