ALGINATE LYASE FROM PSEUDOMONAS-AERUGINOSA CF1 M1 PREFERS THE HEXAMERIC OLIGOMANNURONATE AS SUBSTRATE/

In order to investigate the catalytic properties of alginate lyase fro m Pseudomonas aeruginosa CF1/M1, a clinical isolate, regarding the cap acity to perform beta-elimination on oligomannuronates of defined leng th (2-9), the alginate lyase was purified periplasmic extracts. A puri fication method for unsaturated and saturated oligomannuronates applyi ng anionic exchange chromatography on a FPLC apparatus was established . The alginate lyase showed the highest activity, when hexamers were p rovided as substrate. This indicated that the alginate lyase best acco mmodates a chain of six alginate residues in the active center. As a m inimum chain length, the pentameric oligomannuronate was still accepte d as substrate. Mannuronate oligomers shorter than the pentamer were n ot accepted as substrate for alginate lyase. Furthermore, oligomer pat tern analysis of polymannuronate which was subjected to p-elimination by alginate lyase revealed that the trimer is the most abundant oligom er. These data indicated that p-elimination and cleavage occurred at m annuronic acid residue no. 3 of the accommodated hexameric alginate ch ain. (C) 1998 Federation of European Microbiological Societies. Publis hed by Elsevier Science B.V. All rights reserved.