ISSN:
1573-6830
Keywords:
Alzheimer's disease
;
β-amyloid precursor protein
;
acetylcholinesterase
;
β/A4 peptide
;
secretase
;
amyloidosis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary 1. It was recently proposed that acetylcholinesterase (AChE), in addition to its esteratic activity, has proteolytic activity such that it may cleave theβ-amyloid precursor (β-APP) within theβ-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 ofβ-APP. 2. The ability of various preparations of AChE and BuChE to hydrolyze two synthetic fragments ofβ-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 toβ-pancreatic trypsin. 6. These data indicate that the proteinase activity found in these commercial preparations of AChE is due to contamination with trypsin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00733756
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