Cloning and characterization of trypsin- and chymotrypsin-like proteases from the midgut of the sand fly vector Phlebotomus papatasi
Cloning and characterization of trypsin- and chymotrypsin-like proteases from the midgut of the sand fly vector Phlebotomus papatasi
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DOI：
10.1016/s0965-1748(02)00187-x
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发表时间：
2003-02-01
影响因子：
3.8
通讯作者：
Valenzuela, JG
中科院分区：
文献类型：
--
作者：
Ramalho-Ortigao, JM;Kamhawi, S;Valenzuela, JG
胰蛋白酶和胰凝乳蛋白酶丝氨酸蛋白酶是双翅目昆虫中肠的主要消化蛋白酶，也参与了媒介-寄生虫关系的许多方面。在白蛉中，这些蛋白酶已被证明是利什曼原虫在中肠内生长和发育的潜在障碍。在这里，我们描述的序列和部分特性的Phlebotomus papatasi中肠丝氨酸蛋白酶：两个糜蛋白酶样（Ppchym 1和Ppchym 2）和四个胰蛋白酶样（Pptryp 1-Pptryp 4）。所有六种酶都显示出每种类型的典型结构特征，包括组氨酸、天冬氨酸和丝氨酸（H/D/S）催化三联体、六个保守的半胱氨酸残基和其他参与底物特异性的氨基酸残基。它们还显示出与来自其他昆虫载体的对应物（例如冈比亚按蚊和埃及伊蚊）的高度同源性（40 - 60%相同残基）。这六种蛋白酶的mRNA表达谱差异很大：两种胰蛋白酶样蛋白酶（Pptryp 1和Pptryp 2）下调，一种（Pptryp 4）在血液喂养后上调。这两种胰凝乳蛋白酶样酶显示出与来自Ae的早期和晚期胰蛋白酶相似的表达行为。埃及人。出版社：Elsevier Science Ltd
Trypsin and chymotrypsin serine proteases are the main digestive proteases in Diptera midguts and are also involved in many aspects of the vector-parasite relationship. In sand flies, these proteases have been shown to be a potential barrier to Leishmania growth and development within the midgut. Here we describe the sequence and partial characterization of six Phlebotomus papatasi midgut serine proteases: two chymotrypsin-like (Ppchym1 and Ppchym2) and four trypsin-like (Pptryp1-Pptryp4). All six enzymes show structural features typical to each type, including the histidine, aspartic acid, and serine (H/D/S) catalytic triad, six conserved cysteine residues, and other amino acid residues involved in substrate specificity. They also show a high degree of homology (4060% identical residues) with their counterparts from other insect vectors, such as Anopheles gambiae and Aedes aegypti. The mRNA expression profiles of these six proteases vary considerably: two trypsin-like proteases (Pptryp1 and Pptryp2) are downregulated and one (Pptryp4) upregulated upon blood feeding. The two chymotrypsin-like enzymes display expression behavior similar to that of the early and late trypsins from Ae. aegypti. Published by Elsevier Science Ltd.