title: Investigation of the effect of lannate on kinetic parameters of acetylcholinesterase: slightly concave mixed-type of inhibition system.
abstract: The effect of lannate on kinetic parameters of camel retina acetylcholinesterase is investigated in the present study. The Ks for the hydrolysis of acetylthiocholine iodide was found to be 0.086 mM in the control system; a value that increased in the lannate treated systems. The Vmax was 0.853 mumole/min/mg protein for the control system while it decreased in the lannate treated systems. Dixon as well as Lineweaver-Burk plots and their secondary replots indicated that the nature of the inhibition is of the slightly concave mixed type, which is considered to be a 'semi-pure competitive' and 'semi-partial as well as semi-pure non-competitive' mixture. The values of Ki(slope) and KI(intercept) were estimated as 0.143 microM and 0.179 microM respectively. The KI was greater than Ki indicating that lannate has a greater affinity of binding for the peripheral site than the active site of the camel retina AChE.
authors.affiliation: Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: M A
authors.initials: MA
authors.lastname: Kamal
mesh_terms: D000110:Acetylcholinesterase / Q000187:drug effects* / Q000378:metabolism*; D000122:Acetylthiocholine / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002162:Camelus; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D006868:Hydrolysis; D007700:Kinetics; D008724:Methomyl / Q000494:pharmacology*; D012160:Retina / Q000201:enzymology
chemical_list: D002800:Cholinesterase Inhibitors; D008724:Methomyl; D000122:Acetylthiocholine; D000110:Acetylcholinesterase