An α2,3-Sialyltransferase from Photobacterium phosphoreum with Broad Substrate Scope: Controlling Hydrolytic Activity by Directed Evolution.

ABSTRACT: Defined sialoglycoconjugates are important molecular probes for studying the role of sialylated glycans in biological systems. We show that the α2,3-sialyltransferase from Photobacterium phosphoreum JT-ISH-467 (2,3SiaT_pph ) tolerates a very broad substrate scope for modifications in the sialic acid part, including bulky amide variation, C5/C9 substitution, and C5 stereoinversion. To reduce the enzyme's hydrolytic activity, which erodes the product yield, an extensive structure-guided mutagenesis study identified three variants that show up to five times higher catalytic efficiency for sialyltransfer, up to ten times lower efficiency for substrate hydrolysis, and drastically reduced product hydrolysis. Variant 2,3SiaT_pph (A151D) displayed the best performance overall i

SUBMITTER: Mertsch A 

PROVIDER: S-EPMC7540698 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature