The effect of the experimental antitumor agent caracemide on brain choline acetyltransferase

✍ Scribed by B. T. Ho; L. W. Tansey; R. Feiffer; R. A. Newman; D. Farquhar; W. S. Field; I. H. Krakoff

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 291 KB
• Volume: 19
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490190116

✦ Synopsis

Caracemide was found to inhibit choline acetyltransferase (CAT) from rat brain. A concentration of 0.5 mM caracemide inhibited the enzyme by 93%, whereas a degradation product from caracemide, N-(methylcarbamoyloxy)acetamide, produced only a 50% inhibition. Two other degradation products, N-(methyl-carbamoy1oxy)-"-methylurea and N-hydroxy-N'-methylurea, lacked any inhibitory activity. With bovine brain CAT, caracemide showed noncompetitive inhibition with the substrate choline, K, 337 pM, Ki 240 pM, V,,, 2.83 nmol acetylcholine formed/ minlmg protein and mixed inhibition with the substrate acetyl-CoA, K, 21 pM, Ki 146 pM, V , , 3.85 nmol acetylcholine formed/min/mg protein.