Tetramer organizing polyproline-rich peptides identified by mass spectrometry after release of the peptides from Hupresin-purified butyrylcholinesterase tetramers isolated from milk of domestic pig (Sus scrofa).

ABSTRACT: Milk of the domestic pig has 10 times more butyrylcholinesterase (BChE) per mL than porcine serum. We purified BChE from porcine milk by affinity chromatography on Hupresin-Sepharose. The pure porcine BChE (PoBChE) was a tetramer with a molecular weight of 340,000, similar to that of human BChE tetramers. The C-terminal 40 residues of PoBChE constitute the tetramerization domain. The glue that holds the 4 BChE subunits together is a polyproline-rich peptide. Mass spectrometry analysis of trypsin-digested PoBChE identified a variety of polyproline-rich peptides originating from 12 different proteins. The donor proteins exist in the nucleus or cytoplasm of cells and contribute their polyproline-rich peptides after a cell is degraded. The secreted PoBChE scavenges the polyproline-rich peptide

SUBMITTER: Saxena A 

PROVIDER: S-EPMC6157292 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature