| Literature DB >> 19038284 |
K S Shashidhara1, Sushama M Gaikwad.
Abstract
Energetics of the catalysis of Class II alpha-mannosidase (E.C.3.2.1.24) from Aspergillus fischeri was studied. The enzyme showed Kcat/Km for Man (alpha1-3) Man, Man (alpha1-2) Man and Man (alpha1-6) Man as 7488, 5376 and 3690 M(-1) min(-1), respectively. The activation energy, Ea was 15.14, 47.43 and 71.21 kJ/mol for alpha1-3, alpha1-2 and alpha1-6 linked mannobioses, respectively, reflecting the energy barrier in the hydrolysis of latter two substrates. The enzyme showed Kcat/Km as 3.56x10(5) and 4.61x10(5) M(-1) min(-1) and Ea as 38.7 and 8.92 kJ/mol, towards pNPalphaMan and 4-MeUmbalphaMan, respectively. Binding of Swainsonine to the enzyme is stronger than that of 1-deoxymannojirimycin.Entities:
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Year: 2008 PMID: 19038284 DOI: 10.1016/j.ijbiomac.2008.10.012
Source DB: PubMed Journal: Int J Biol Macromol ISSN: 0141-8130 Impact factor: 6.953