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Updated: Jun 10, 2026

Identification of Kinase-substrate Pairs Using High Throughput Screening
Published on: August 29, 2015
AMPK beta subunits display isoform specific affinities for carbohydrates
Ann Koay1, Ben Woodcroft, Emma J Petrie
1Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.
Abstract:
AMP-activated protein kinase (AMPK) is a heterotrimer of catalytic (alpha) and regulatory (beta and gamma) subunits with at least two isoforms for each subunit. AMPK beta1 is widely expressed whilst AMPK beta2 is highly expressed in muscle and both beta isoforms contain a mid-molecule carbohydrate-binding module (beta-CBM). Here we show that beta2-CBM has evolved to contain a Thr insertion and increased affinity for glycogen mimetics with a preference for oligosaccharides containing a single alpha-1,6 branched residue. Deletion of Thr-101 reduces affinity for single alpha-1,6 branched oligosaccharides by 3-fold, while insertion of this residue into the equivalent position in the beta1-CBM sequence increases affinity by 3-fold, confirming the functional importance of this residue.
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