Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acetylcholinesterase (AChE) is an integral erythrocyte membrane protein. A role for the enzyme in the developing human erythron is being explored. Assays of AchE by the standard Ellman technique overestimate the amount of enzyme by failing to account for the contribution of hemoglobin to the optical density of the reaction mixture. Furthermore, reliance on substrate selection alone for specificity is unsatisfactory. Incorporation of inhibitors of "true" AchE and of pseudocholinesterase confer greater ability to distinguish one enzyme from the other. In our experience, the inhibitor constant (Kl) for edrophonium, which is highly specific for AChE, is approximately 5 x 10(-5) M against adult human erythrocytes that contain significantly more total cholinesterase activity than do erythrocytes from umbilical cord blood. This consists of both "true" and "pseudo" enzyme, the former predominating and accounting for 0.75-1.65 (mean 1.02, median 0.87) femtomoles of substrate hydrolysed per min per cell in adult blood, with values of 0.15-1.04 (mean 0.71, median 0.73) obtained on cord blood. Moreover, the enzyme activity in neonatal erythrocytes has a rather different inhibitor profile from that of adult cells. AChE was also demonstrated in fresh (ALL) and cultured (K562 and HL60) human leukemic cells, as well as in primitive granulocyte-macrophage and erythroid cells cloned from normal human bone marrow. In the erythroid colonies the enzyme activity was 0-3.76 (mean 1.20, median 0.76) femtomoles per min per cell, apparently the first successful measurement of AChE in such cells.
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PMID:Acetylcholinesterase in the human erythron. II. Biochemical assay. 316 38

The Cartwright (Yt) blood group antigens have previously been shown likely to reside on a phosphatidylinositol-linked erythrocyte membrane protein. In this study, an unusual individual whose red blood cells (RBCs) were of the previously unreported Yt(a-b-) phenotype were used, along with normal Yt(a+) cells, to investigate serologically and biochemically the relationship of the Yta antigen to known phosphatidylinositol-linked erythrocyte proteins. Yt(a-b-) RBCs expressed normal amounts of various phosphatidyl-inositol-linked proteins except acetylcholinesterase. Further, human anti-Yta reacted with acetylcholinesterase in immunoprecipitation and immunoblotting studies. Thus, acetylcholinesterase is now identified as the protein bearing the Yt blood group antigens.
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PMID:Human erythrocyte acetylcholinesterase bears the Yta blood group antigen and is reduced or absent in the Yt(a-b-) phenotype. 842 72