Amphiphilic and hydrophilic forms of acetyl- and butyrylcholinesterase in human brain

✍ Scribed by J. Sáez-Valero; P. L. Tornel; E. Muñoz-Delgado; C. J. Vidal

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 1007 KB
• Volume: 35
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490350610

✦ Synopsis

Human brain acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were sequentially extracted, first with a Tris-saline buffer (S,) and then with 1% (wlv) Triton X-100 (S,). About 20 and 30% of the AChE and BuChE activities were recovered in S, and most of the remaining enzymes in S,. Main molecular forms of about 10.5 S and 12.0 S, G, forms of AChE and BuChE, and smaller amounts of 4.5 S and 5.5 S forms, G, species of AChE and BuChE, were measured in S,. Application of Triton X-114 phase partitioning and affinity chromatography on phenyl-agarose to S, revealed that 25% of the AChE and none of the BuChE molecuIes displayed amphiphilic properties. Analysis of the enzyme activity retained by the phenyl-agarose showed that G, AChE constituted the bulk of the amphiphilic molecules released without detergent. Main G4 forms of AChE and BuChE were found in the S, extract. Eighty and 45% of the AChE and BuChE activities in S, were measured in the detergent-rich phase by Triton X-114 phase partitioning. Thus, most of the AChE and about half of the BuChE molecules in S, displayed amphiphilic properties. The main peak of BuChE, a 12.0 S form in gradients made with Triton X-100, splits into two peaks of 9.5 S and 12.5 S in Brij 96containing gradients. This suggests that hydrophilic G4 BuChE forms are predominant in S, and that hydrophilic and amphiphilic isoforms coexist in S,.