Proteolysis at the secretase and amyloidogenic cleavage sites of theβ-amyloid precursor protein by acetylcholinesterase and butyrylcholinesterase using model peptide substrates

Autor: Serres, M., Sherman, D., Chestnut, W., Merrill, B. M., Viveros, O. H., Diliberto, E. J.
Zdroj: Cellular and Molecular Neurobiology; June 1993, Vol. 13 Issue: 3 p279-287, 9p
Abstrakt: 1.It was recently proposed that acetylcholinesterase (AChE), in addition to its esteratic activity, has proteolytic activity such that it may cleave theß-amyloid precursor (ß-APP) within theß-amyloid sequence. The purpose of this paper was to examine further whether AChE or butyrylcholinesterase (BuChE) had associated proteinase activity that was involved in the metabolism ofß-APP.2.The ability of various preparations of AChE and BuChE to hydrolyze two synthetic fragments ofß-APP695 as model substrates containing the normal and aberrant cleavage sites was studied.3.Digestion of these synthetic substrates with commercial preparations ofElectrophorus electricus AChE indicated the presence of a trypsin-like proteolytic activity cleaving each peptide at the carboxy-terminal side of an internal lysine residue.4.Purification of the trypsin-like proteinase activity by aminobenzamidine affinity chromatography yielded a preparation that was devoid of AChE activity but retained all of the proteinase activity.5.Amino-terminal sequence analysis of this preparation showed that the first 13 amino acid residues were identical toß-pancreatic trypsin.6.These data indicate that the proteinase activity found in these commercial preparations of AChE is due to contamination with trypsin.
Databáze: Supplemental Index
Externí odkaz: