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Amphiphilic Detergent‐Soluble Acetylcholinesterase from Torpedo marmorata: Characterization and Conversion by Proteolysis to a Hydrophilic Form
Author(s) -
Stieger S.,
Brodbeck U.
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb07111.x
Subject(s) - torpedo , proteolysis , acetylcholinesterase , amphiphile , chemistry , biochemistry , characterization (materials science) , chromatography , organic chemistry , enzyme , materials science , copolymer , nanotechnology , receptor , acetylcholine receptor , polymer
The membrane‐bound acetylcholinesterase (AChE) from the electric organ of Torpedo marmorata was solubilized by Triton X‐100 or by treatment with proteinase K and purified to apparent homogeneity by affinity chromatography. Although the two forms differed only slightly in their subunit molecular weight (66,000 and 65,000 daltons, respectively), considerable differences existed between native and digested detergent‐soluble AChE. The native enzyme sedimented at 6.5 S in the presence of Triton X‐100 and formed aggregates in the absence of detergent. The digested enzyme sedimented at 7.5 S in the absence and in the presence of detergent. In contrast to the detergent‐solubilized AChE, the proteolytically derived form neither bound detergent nor required amphiphilic molecules for the expression of catalytic activity. This led to the conclusion that limited digestion of detergent‐soluble AChE results in the removal of a small hydrophobic peptide which in vivo is responsible for anchoring the protein to the lipid bilayer.