8yg2
From Proteopedia
Crystal structure of amyloidogenic peptide Piv-NFGAIL-NH2 from Islet Amyloid Polypeptide
Structural highlights
FunctionIAPP_HUMAN Selectively inhibits insulin-stimulated glucose utilization and glycogen deposition in muscle, while not affecting adipocyte glucose metabolism. Publication Abstract from PubMedAmine modification through nucleophilic attack of the amine functionality is a very common chemical transformation. Under biorelevant conditions using acidic-to-neutral pH buffer, however, the nucleophilic reaction of alkyl amines (pKa approximately 10) is not facile due to the generation of ammonium ions lacking nucleophilicity. Here, we disclose a unique molecular transformation system, catalysis driven by amyloid-substrate complex (CASL), that promotes amine modifications in acidic buffer. Ammonium ions attached to molecules with amyloid-binding capability were activated through deprotonation due to the close proximity to the amyloid catalyst formed by Ac-Asn-Phe-Gly-Ala-Ile-Leu-NH(2) (NL6), derived from islet amyloid polypeptide (IAPP). Under the CASL conditions, alkyl amines underwent various modifications, i.e., acylation, arylation, cyclization, and alkylation, in acidic buffer. Crystallographic analysis and chemical modification studies of the amyloid catalysts suggested that the carbonyl oxygen of the Phe-Gly amide bond of NL6 plays a key role in activating the substrate amine by forming a hydrogen bond. Using CASL, selective conversion of substrates possessing equivalently reactive amine functionalities was achieved in catalytic reactions using amyloids. CASL provides a unique method for applying nucleophilic conversion reactions of amines in diverse fields of chemistry and biology. Catalysis driven by an amyloid-substrate complex.,Sawazaki T, Sasaki D, Sohma Y Proc Natl Acad Sci U S A. 2024 May 7;121(19):e2314704121. doi: , 10.1073/pnas.2314704121. Epub 2024 May 1. PMID:38691589[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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