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Updated: Aug 9, 2026
Hot Biological Catalysis: Isothermal Titration Calorimetry to Characterize Enzymatic Reactions
Published on: April 4, 2014
Enzyme kinetics of hevamine, a chitinase from the rubber tree Hevea brasiliensis
E Bokma1, T Barends, A C Terwissch van Scheltingab
1Department of Biochemistry, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands. e.bokma@chem.rug.nl
Abstract:
The enzyme kinetics of hevamine, a chitinase from the rubber tree Hevea brasiliensis, were studied in detail with a new enzyme assay. In this assay, the enzyme reaction products were derivatized by reductive coupling to a chromophore. Products were separated by HPLC and the amount of product was calculated by peak integration. Penta-N-acetylglucosamine (penta-nag) and hexa-N-acetylglucosamine (hexa-nag) were used as substrates. Hexa-nag was more efficiently converted than penta-nag, which is an indication that hevamine has at least six sugar binding sites in the active site. Tetra-N-acetylglucosamine (tetra-nag) and allosamidin were tested as inhibitors. Allosamidin was found to be a competitive inhibitor with a K(i) of 3.1 microM. Under the conditions tested, tetra-nag did not inhibit hevamine.
