Substrate and product hydrolysis specificity in family 11 glycoside hydrolases: an analysis of Penicillium funiculosum and Penicillium griseofulvum xylanases.
Two genes encoding family 11 endo-(1,4)-beta-xylanases from Penicillium griseofulvum (PgXynA) and Penicillium funiculosum (PfXynC) were heterologously expressed in Escherichia coli as glutathione S-transferase fusion proteins, and the recombinant enzymes were purified after affinity chromatography and proteolysis. PgXynA and PfXynC were identical to their native counterparts in terms of molecular mass, pI, N-terminal sequence, optimum pH, and enzymatic activity towards arabinoxylan. Further investigation of the rate and pattern of hydrolysis of PgXynA and PfXynC on wheat soluble arabinoxylan showed the predominant production of xylotriose and xylobiose as end products. The initial rate data from the hydrolysis of short xylo-oligosaccharides indicated that the catalytic efficiency increased with increasing chain length (n) of oligomer up to n = 6, suggesting that the specificity region of both Penicillium xylanases spans about six xylose units. In contrast to PfXynC, PgXynA was found insensitive to the wheat xylanase inhibitor protein XIP-I.
Berrin
Jean-Guy
JG
Biosciences FRE-3005-CNRS, Université Paul Cézanne Aix Marseille III, Av. Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
Ajandouz
El Hassan
el H
Georis
Jacques
J
Arnaut
Filip
F
Juge
Nathalie
N
D043364:Endo-1,4-beta Xylanases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D007700:Kinetics; D010407:Penicillium / Q000201:enzymology*; D013379:Substrate Specificity / Q000502:physiology
D006026:Glycoside Hydrolases; D043364:Endo-1,4-beta Xylanases