Author/Editor		Massa, C; Clausen, MH; Stojan, J; Lamba, D; Campa, C
Title		Study of the mode of action of a polygalacturonase from the phytopathogen Burkholderia cepacia
Type		članek
Source		Biochem J
Vol. and No.		Letnik 407, št. 2
Publication year		2007
Volume		str. 207-17
Language		eng
Abstract		We have recently isolated and heterologously expressed an endo-polygalacturonase from the phytopathogen Burkholderia cepacia (BcPeh28A). Endo-polygalacturonases belong to the glycoside hydrolase family 28 and are responsible for the hydrolysis of non-esterified region of pectins. The mode of action of BcPeh28A on different substrates has been investigated and its enzymatic mechanism elucidated. The hydrolysis of polygalacturonate indicates that BcPeh28A is a non-processive enzyme that releases oligomers with chain length ranging from 2 to 8. By inspection of products progression curves, a kinetic model has been generated and extensively tested. It has been used to derive the kinetic parameters that describe the time course of the formation of six predominant products. Moreover, the investigation of the enzymatic activity on shorter substrates that differ in their overall length and methylation patterns sheds light on the architecture of BcPeh28A active site. Specifically the tolerance of individual sites towards methylated saccharide units was rationalized, based on hydrolysis of hexagalacturonides with different methylation patterns.
Descriptors		BURKHOLDERIA CEPACIA POLYGALACTURONASE KINETICS BINDING SITES METHYLATION