Zhao, X.P., Zhang, J.Y., Yang, S.Z., Liu, K.W., & Yu, D. 2001 [Functional groups of alkaline phosphatase from Ericerus pela.]. Acta Entomologica Sinica 44(3) 257-262.

Notes: Alkaline phosphatase was purified from female E. pela adults through homogenization, n-butanol extraction, ammonium sulfate fractionation and Sephadex G-150 column gel filtration. The purification attained 16.83-fold of the enzyme with specific activity at 136.65 U/mg. The optimum pH value and temperature for the enzyme were 8.5 and 37°C, respectively. The Km was 2.08 mmol/litre, with disodium phenyl phosphate as its substrate. The enzyme was selectively modified by phenylmethylsulfonyl-fluoride (PMSF), N-bromosuccinimide (NBS), dithiothreitol (DTT), trinitrobenzenesulfonic acid (TNBS), PCMB, SUAN, bromoacetic acid and iodoacetic acid. The reactions of alkaline phosphatase to PMSF, NBS, TNBS, SUAN and DDT resulted in the reduction of enzyme activity, showing the dose-response curves within certain dosages of the modifiers. Bromoacetic acid, iodoacetic acid and p-chloromercuribenzoate had little inhibitory effect on alkaline phosphatase activity. It is suggested that Ser, Lys and Trp residues should be considered as indespensible functional groups of alkaline phosphatase and the partial disulfide bonds as essential for the function of the enzymes.