Identification of a 17 S asymmetric butyrylcholinesterase in chick muscle by monoclonal antibodies.
A 20 S asymmetric (non-globular) form of acetylcholinesterase (AChE, E.C. 3.1.1.7) has been purified from 1-day chick muscle. This form is a hybrid molecule containing both AChE and butyrylcholinesterase (BuChE, E.C. 3.1.1.8) catalytic subunits, linked through a collagenous tail. However, the 20 S hybrid AChE/BuChE could not account for the total enzyme activities of AChE and BuChE in a high-salt/Triton X-100 extract of 1-day chick muscle. By applying AChE- and BuChE-specific monoclonal antibodies for immunoadsorption, homogeneous asymmetric AChE and BuChE forms were also identified in that extract. The homogeneous BuChE accounts for 20% of the total activity of the asymmetric BuChE present and sediments at 17 S. About 6% of the asymmetric AChE present is, likewise, in a homogeneous, instead of the hybrid, form. The 17 S asymmetric BuChE does not react with monoclonal antibodies specific for the collagenous tail of the hybrid 20 S AChE/BuChE molecule, suggesting that the collagenous subunit differs between these two forms.
Tsim
K W
KW
MRC Molecular Neurobiology Unit, Medical Research Council Centre, Cambridge, U.K.
Randall
W R
WR
Barnard
E A
EA
D000110:Acetylcholinesterase / Q000032:analysis* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D002091:Butyrylcholinesterase / Q000032:analysis* / Q000276:immunology; D002645:Chickens; D002802:Cholinesterases / Q000032:analysis*; D003094:Collagen / Q000032:analysis; D008968:Molecular Conformation; D009132:Muscles / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology
D000911:Antibodies, Monoclonal; D003094:Collagen; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D002802:Cholinesterases