Entamoeba histolytica: Soluble and membrane-associated neutral sphingomyelinase-C and other unidentified esterase activity

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• 作者：Javier Vargas-Villarreal ; Rebeca Palacios-Corona ; Carlos Herná ; ndez-Luna ; Benito David Mata-Cá ; rdenas ; Victor M. Torres de la Cruz ; Elva I. Corté ; s-Gutié ; rrez ; Francisco Gonzá ; lez-
• 关键词：Amoebae ; Entamoeba histolytica ; Sphingomyelinase-C EC 3.1.4.12 ; Sphingomyelinase-D EC 3.1.4.41 ; Phosphorylcholine phosphatase EC 3.1.3.75 ; Cytolysins ; Lipid metabolism
• 刊名：Experimental Parasitology
• 出版年：2010
• 出版时间：August 2010
• 年：2010
• 卷：125
• 期：4
• 页码：394-399
• 全文大小：298 K

文摘

Sphingomyelinase (SMase) activity was measured in Entamoeba histolytica particulate and soluble subcellular fractions. The effects on SMase of incubation time, total protein concentration, pH, and several divalent cations were determined. SMase-C and other unidentified esterase activity were detected in soluble and particulate fractions. SMase-C was 94.5–96.0 % higher than the unidentified esterase activity. Soluble and insoluble SMase-C specific activities increased with protein dose and incubation time. Soluble and insoluble SMase-C activities were maximum at pH 7.5 and were dependent on Mg²⁺, Mn²⁺, or Co²⁺, and inhibited by Zn²⁺, Hg²⁺, Ca²⁺, and EDTA. SMase-C was active in the pH range of 3–10 and its maximum activity was at pH 7.5. The soluble and insoluble SMases have remarkably similar physicochemical properties, strongly suggesting that E. histolytica has just one isoform of neutral SMase-C that had not been described before and might be essential for E. histolytica metabolism or virulence.