Origin of polyproline-rich peptides in human butyrylcholinesterase tetramers. (25th November 2016)

• Record Type: Journal Article
• Authors: Peng, Hong; Schopfer, Lawrence M.; Lockridge, Oksana
• Is Part Of: Chemico-biological interactions. Volume 259:Part B(2016)
• Page Start: 63
• Page End: 69
• Publication Date: 2016-11-25
• Subjects: Polyproline -- Mass spectrometry -- Lamellipodin -- Butyrylcholinesterase -- Tetramerization domain; BChE butyrylcholinesterase -- HuBChE human butyrylcholinesterase -- AChE acetylcholinesterase -- LC-MS/MS liquid chromatography tandem mass spectrometry -- MALDI-TOF matrix-assisted laser- ionization time-of-flight -- NCBI National Center for Biotechnology Information -- BLASTp Basic Local Alignment Search Tool for proteins from NCBI; Biochemistry -- Periodicals; Toxicological chemistry -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biochimie -- Périodiques; Toxicologie biochimique -- Périodiques; 572
• DOI: 10.1016/j.cbi.2016.02.007
• Languages: English
• ISSNs: 0009-2797

Abstract

Abstract: The human butyrylcholinesterase (HuBChE) tetramer is composed of 4 identical subunits and a noncovalently bound polyproline-rich peptide. In a previous report we identified lamellipodin as the source of the polyproline-rich peptides in HuBChE tetramers purified from plasma. Our current goal was to identify proteins in addition to lamellipodin that donate polyproline-rich peptides to plasma HuBChE tetramers. Peptides were released from 1 mg of pure plasma-derived HuBChE tetramers by boiling. Mass spectrometry identified 74 polyproline-rich peptides. MALDI-TOF mass spectra and spectral counting of the LC-MS/MS data supported the conclusion that lamellipodin accounted for 70% of the polyproline-rich peptides. Additional precursor proteins were matched through BLASTp searches, suggesting but not proving, that 20 proteins including UDP- N -acetyl glucosamine transferase ALG13 homolog, leiomodin 2, and zinc finger homeobox protein 2 are sources of polyproline-rich peptides found in HuBChE tetramers. Eighteen polyproline-rich peptides had no match in the human protein database. In conclusion, HuBChE assembles into tetramers through interaction of its C-terminal domain with polyproline peptides derived from a variety of proteins. Highlights: Assembly of human BChE into tetramers requires polyproline peptides. 70% of the polyproline peptides in plasma BChE derive from lamellipodin. Other precursor proteins donate 30% of the polyproline-rich peptides.