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KnowVolution Campaign of an Aryl Sulfotransferase Increases Activity toward Cellobiose
Author(s) -
Islam Shohana,
Laaf Dominic,
Infanzón Belén,
Pelantová Helena,
Davari Mehdi D.,
Jakob Felix,
Křen Vladimír,
Elling Lothar,
Schwaneberg Ulrich
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201803729
Subject(s) - cellobiose , sulfation , chemistry , aryl , stereochemistry , biocatalysis , chemoselectivity , linker , cellulose , biochemistry , combinatorial chemistry , organic chemistry , catalysis , reaction mechanism , alkyl , computer science , operating system , cellulase
Sulfated polysaccharides such as cellulose can mimic the functionalities of pathophysiologically important glycosaminoglycans. Enzymatic sulfation offers a green chemistry route to selective (mono)sulfation of oligosaccharides (e.g., cellobiose as a building block of cellulose) in aqueous solution, at ambient temperature, and high chemoselectivity. Here, we report the first KnowVolution campaign for the aryl sulfotransferase B (ASTB) from Desulfitobacterium hafniense to advance ASTB toward a synthetically attractive biocatalyst. The generated final recombination variant (ASTB‐M5) carries two amino acid substitutions (Leu446Pro and Val579Lys) leading to an up to 7.6‐fold increase in specific activity (6.15 U mg −1 ) that was obtained with one round of KnowVolution. Mass spectrometry analysis confirmed a monosulfated product of cellobiose and structure elucidation by NMR confirmed the sulfation at the positions C‐3 or C‐4 of GlcNAc‐linker‐ t Boc as opposed to the preferred C‐6 by chemical means. Computational analysis suggested an important role of Leu446Pro in substrate‐binding and recognized Val579Lys as a distal substitution.