Disulfide bonds of acetylcholinesterase

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6985966

MacPhee-Quigley, K; Vedvick, T; Taylor, P; Taylor, S

The positions of the inter- and intrasubunit disulfide bridges were established for the 11S form of acetylcholinesterase (AChE) isolated from Torpedo californica. A major form of AChE localized within the basal lamina of the synapse is a dimensionally asymmetric molecule which contains either two (13S) or three (17S) sets of catalytic subunits linked to collagenous and non-collagenous structural subunits. Limited proteolysis yields a tetramer of catalytic subunits which sediments at 11S. Each catalytic subunit contains 8 cysteine residues. Initially, these Cys residues were identified following trypsin digestion of the reduced protein alkylated with (/sup 14/C)-iodoacetate. Peptides were resolved by gel filtration followed by reverse phase HPLC. To determine the disulfide bonding profile, native non-reduced 11S AChE was treated with a fluorescent, sulfhydryl-specific reagent, monobromobimane, prior to proteolytic digestion. One fluorescent Cys peptide was identified indicating that a single sulfhydryl residue was present in its reduced form. Three pairs of disulfide bonded peptides were identified, sequenced, and localized in the polypeptide chain. The Cys residue that is located in the C-terminal tryptic peptide was disulfide bonded to an identical peptide and thus forms the intersubunit crosslink. Finally, the cysteine positions have been compared with the sequence of the homologous protein, thyroglobulin. Both likely share a common pattern of folding.

• Research Organization: Univ. of California, San Diego, La Jolla
• OSTI ID: 6985966
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
AQUATIC ORGANISMS
CARBON 14 COMPOUNDS
CARBOXYLESTERASES
CARBOXYLIC ACIDS
CHEMICAL BONDS
CHEMICAL REACTIONS
CHOLINESTERASE
CHROMATOGRAPHY
CROSS-LINKING
CYSTEINE
DISULFIDES
ENZYMES
ESTERASES
FISHES
HYDROLASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MOLECULAR STRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDES
POLYMERIZATION
PROTEINS
SEPARATION PROCESSES
THIOLS
TRACER TECHNIQUES
VERTEBRATES