Kamiguti A S, Zuzel M, Theakston R D
Department of Haematology, Royal Liverpool University Hospital, University of Liverpool, UK.
Braz J Med Biol Res. 1998 Jul;31(7):853-62. doi: 10.1590/s0100-879x1998000700001.
Metalloproteinases and disintegrins are important components of most viperid and crotalid venoms. Large metalloproteinases referred to as MDC enzymes are composed of an N-terminal Metalloproteinase domain, a Disintegrin-like domain and a Cys-rich C-terminus. In contrast, disintegrins are small non-enzymatic RGD-containing cysteine-rich polypeptides. However, the disintegrin region of MDC enzymes bears a high degree of structural homology to that of the disintegrins, although it lacks the RGD motif. Despite these differences, both components share the property of being able to recognize integrin cell surface receptors and thereby to inhibit integrin-dependent cell reactions. Recently, several membrane-bound MDC enzymes, closely related to soluble venom MDC enzymes, have been described in mammalian cells. This group of membrane-anchored mammalian enzymes is also called the ADAM family of proteins due to the structure revealing A Disintegrin And Metalloproteinase domains. ADAMs are involved in the shedding of molecules from the cell surface, a property which is also shared by some venom MDC enzymes.
金属蛋白酶和解整合素是大多数蝰蛇科和响尾蛇科毒液的重要组成部分。被称为MDC酶的大型金属蛋白酶由一个N端金属蛋白酶结构域、一个类解整合素结构域和一个富含半胱氨酸的C端组成。相比之下，解整合素是一种不含酶的、富含半胱氨酸且含有RGD的小多肽。然而，MDC酶的解整合素区域与解整合素的该区域具有高度的结构同源性，尽管它缺乏RGD基序。尽管存在这些差异，但这两种成分都具有能够识别整合素细胞表面受体并由此抑制整合素依赖性细胞反应的特性。最近，在哺乳动物细胞中发现了几种与可溶性毒液MDC酶密切相关的膜结合MDC酶。由于其结构显示出解整合素和金属蛋白酶结构域，这一类膜锚定的哺乳动物酶也被称为ADAM蛋白家族。ADAM参与细胞表面分子的脱落，这也是一些毒液MDC酶所共有的特性。
