一株深水稻固氮鱼腥藻的碱性磷酸酶活性。

Alkaline phosphatase activities of anAnabaena sp. from deep-water rice.

机构信息

the Algal Research Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, 221 005, Varanasi, India.

出版信息

World J Microbiol Biotechnol. 1992 Nov;8(6):585-8. doi: 10.1007/BF01238793.

Abstract

Anabaena sp. grew with mono- and di-ester phosphate compounds as sources of phosphate, indicating the presence of phosphomonoesterase (PMEase) and phosphodiesterase (PDEase) activities. Cell-bound PMEase and PDEase activities were detected during growth in 0.5 and 10 mg PO4l(-1) only when the cellular phosphate concentration fell to 0.46% of cell protein and the activities increased as cellular phosphate content decreased. The Km values for these enzymes were 0.3MM forp-nitrophenyl phosphate and 0.2MM for bis-p-nitrophenyl phosphate, respectively. Only PMEase activity was found extracellularly. The pH optima for PMEase and PDEase were 10.2 and 10.4, respectively, and the temperature optima at pH 10.2 were 37°C and 40°C, respectively. Ca(2+) increased the enzyme activities while Zn(2+) caused marked inhibition. The inorganic phosphate repressed the cellular PMEase activity after a lag of 4 h.

摘要

鱼腥藻能利用单酯和二酯磷酸盐作为磷源生长，这表明其存在磷酸单酯酶 (PMEase) 和磷酸二酯酶 (PDEase) 活性。只有当细胞内磷酸盐浓度降至细胞蛋白的 0.46%，且细胞内磷酸盐含量下降时，在 0.5 和 10 mg PO4l(-1) 条件下生长时，才会检测到细胞结合的 PMEase 和 PDEase 活性。这些酶的 Km 值分别为 0.3MM 对硝基苯磷酸盐和 0.2MM 双对硝基苯磷酸盐。仅发现细胞外存在 PMEase 活性。PMEase 和 PDEase 的最适 pH 值分别为 10.2 和 10.4，最适温度分别为 37°C 和 40°C。在 pH 值为 10.2 时，Ca(2+) 增加了酶的活性，而 Zn(2+) 则显著抑制了酶的活性。无机磷酸盐在滞后 4 小时后抑制细胞内的 PMEase 活性。