Freitas-Mesquita Anita Leocadio, Meyer-Fernandes José Roberto
Institute of Medical Biochemistry, Federal University of Rio de Janeiro (UFRJ), CCS, Bloco H, University City, Fundão Island, Rio de Janeiro, RJ 21941-590, Brazil.
Int J Mol Sci. 2014 Feb 6;15(2):2289-304. doi: 10.3390/ijms15022289.
Ectophosphatases are surface membrane-bound proteins whose active sites face the extracellular medium. These enzymes have been reported in several microorganisms including a large number of medically relevant fungal species. An effective technique for identifying ectophosphatases is performing phosphatase activity assays using living intact cells. Biochemical characterization of these activities has shown their differential modulation by classical phosphatase inhibitors, divalent metals and pH range. The physiological roles of ectophosphatases are not well established; however, it has been suggested that these enzymes play important roles in nutrition, proliferation, differentiation, adhesion, virulence and infection. Adhesion to host cells is the first step in establishing a fungal infection and ectophosphatases may be one of the first parasite proteins that come into contact with the host cells. Several results indicate that ectophosphatase activities increase the capacity of fungi to adhere to the host cells. In this context, the present review provides an overview of recent discoveries related to the occurrence and possible roles of ectophosphatase activities in fungal cells.
胞外磷酸酶是表面膜结合蛋白，其活性位点面向细胞外介质。这些酶已在多种微生物中被报道，包括大量与医学相关的真菌物种。一种鉴定胞外磷酸酶的有效技术是使用完整活细胞进行磷酸酶活性测定。这些活性的生化特征表明，它们受到经典磷酸酶抑制剂、二价金属和pH范围的差异调节。胞外磷酸酶的生理作用尚未完全明确；然而，有人提出这些酶在营养、增殖、分化、黏附、毒力和感染中发挥重要作用。黏附于宿主细胞是建立真菌感染的第一步，而胞外磷酸酶可能是最早与宿主细胞接触的寄生虫蛋白之一。多项研究结果表明，胞外磷酸酶活性增强了真菌黏附宿主细胞的能力。在此背景下，本综述概述了与真菌细胞中胞外磷酸酶活性的存在及其可能作用相关的最新发现。
