About this Biochemistry, Genetics and Molecular Biology article

Biosynthesis of (1→3)‐β‐d‐glucan (callose) by detergent extracts of a microsomal fraction from Arabidopsis thaliana by Joséphine L.K. Him; Ludovic Pelosi; Henri Chanzy; Jean‐Luc Putaux; Vincent Bulone is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

The aim of this work was to develop a biochemical approach to study (1→3)‐β‐d‐glucan (callose) biosynthesis using suspension cultures of __Arabidopsis thaliana__. Optimal conditions for __in vitro__ synthesis of callose corresponded to an assay mixture containing 50 mm Mops buffer, pH 6.8, 1 mm UDP‐glucose, 8 mm Ca^2+^ and 20 mm cellobiose. The enzyme was Ca^2+^‐dependent, and addition of Mg^2+^ to the reaction mixture did not favour cellulose biosynthesis. Enzyme kinetics suggested the existence of positive homotropic cooperativity of (1→3)‐β‐d‐glucan synthase for the substrate UDP‐glucose, in agreement with the hypothesis that callose synthase consists of a multimeric complex containing several catalytic subunits. Detergents belonging to different families were tested for their ability to extract and preserve membrane‐bound (1→3)‐β‐d‐glucan synthase activity. Cryo‐transmission electron microscopy experiments showed that __n__‐octyl‐β‐d‐glucopyranoside allowed the production of micelle‐like structures, whereas vesicles were obtained with Chaps and Zwittergent 3‐12. The morphology and size of the (1→3)‐β‐d‐glucans synthesized __in vitro__ by fractions obtained with different deterg

Author

Joséphine L.K. Him; Ludovic Pelosi; Henri Chanzy; Jean‐Luc Putaux; Vincent Bulone

Publisher

John Wiley and Sons; Springer; Wiley (Blackwell Publishing); Springer-Verlag; Blackwell Publishing Inc.; Springer Verlag; Wiley; Springer Science and Business Media LLC (ISSN 1432-1327)

Published

2001

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Life Sciences)