Molecular form of human lymphocyte membrane-bound acetylcholinesterase.
The membrane-bound acetylcholinesterase (AchE) from human peripheral blood lymphocyte gives only one symmetrical peak on sucrose density gradient centrifugation in the presence of Triton X-100 detergent, with the calculated sedimentation coefficient of 6.5 S. However, this dimeric form of AchE was converted to a monomeric 3.8 S form when treated with 2-mercaptoethanol and iodoacetic acid. The results are consistent with studies which have shown by sodium dodecyl sulfate gel electrophoresis that the enzyme is built up of two identical monomers inter-linked by disulfide bond(s). Under reducing conditions, revealed a single species of 70,000 molecular weight, whereas under non-reducing conditions, another species of 140,000 molecular weight of the AchE was found. Polyacrylamide gel electrophoresis indicated a single band with AchE activity in the presence of Triton X-100. In contrast, in the absence of the same detergent multiple band pattern could be observed. These results suggest that membrane-bound AchE enzyme is present in homogenous dimeric form on human lymphocyte membrane.
Bartha
E
E
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Rakonczay
Z
Z
Kása
P
P
Hollán
S
S
Gyévai
A
A
D000110:Acetylcholinesterase / Q000097:blood* / Q000302:isolation & purification; D002462:Cell Membrane / Q000201:enzymology; D002846:Chromatography, Affinity; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008214:Lymphocytes / Q000201:enzymology*; D046911:Macromolecular Substances; D008970:Molecular Weight; D017830:Octoxynol; D011092:Polyethylene Glycols
D003902:Detergents; D046911:Macromolecular Substances; D011092:Polyethylene Glycols; D017830:Octoxynol; D000110:Acetylcholinesterase