title: An essential lysine residue of green crab (Scylla Serrata) alkaline phosphatase.
abstract: The values of pKa (10.38) and Hion (10.92 Kcal/mol) have been determined for the ionizing groups controlling activity of green crab alkaline phosphatase. The results suggest that -NH2 of lysine residue responsible for the ionization with pKc = 10.38 and delta H(o)ion = 10.92 Kcal/mol is in the active site of the enzyme. Modification of lysine residues of the enzyme by an excess of 2,4,6-trinitrobenzenesulfonic acid leads to complete inactivation. The two results coincide with each other. Quantitative assessment of the data indicates that among the reactive -NH2 groups modified only one is essential for the activity of the enzyme.
authors.affiliation: Department of Biological Science and Biotechnology, Tsinghua University, Beijing, People's Republic of China.
authors.forename: Q X
authors.initials: QX
authors.lastname: Chen
authors.forename: H M
authors.initials: HM
authors.lastname: Zhou
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D003386:Brachyura / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008239:Lysine / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D014302:Trinitrobenzenesulfonic Acid; D000469:Alkaline Phosphatase; D008239:Lysine