| Autor: |
Raba, Raivo, Aaviksaar, Aavo, Raba, Man, Siigur, Jün |
| Předmět: |
|
| Zdroj: |
European Journal of Biochemistry; 5/2/79, Vol. 96 Issue 1, p151-158, 8p |
| Abstrakt: |
Acetylcholinesterase from cobra (Naja naja oxiana) venom has been purified by affinity chromatography to an homogeneous state, as ascertained by sodium dodecylsulfate/polyacrylamide gel electrophoresis and sedimentation analysis. The specific activity of the preparation was 5000 IU/mg with acetylcholine as substrate. Unlike acetylcholinesterases from insoluble cell structures, the native molecule of the cobra venom enzyme consists of a single polypeptide chain of molecular weight 67000 ± 2000. At high enzyme concentrations (> 0.2 mg/ml, > 1 μM) and ionic strength 0.1 M, it reversibly tends to form higher-molecular-weight 7.1-S aggregates. Despite the apparent structural simplicity of the venom acetylcholinesterase, the disc electrophoresis and isoelectric focusing experiments revealed that the enzyme exists in a number of forms with a common molecular weight but with different isoelectric points. Neuraminidase treatment did not reduce the number of the forms. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
