Ding Y H, Javaherian K, Lo K M, Chopra R, Boehm T, Lanciotti J, Harris B A, Li Y, Shapiro R, Hohenester E, Timpl R, Folkman J, Wiley D C
Department of Cellular and Molecular Biology, Howard Hughes Medical Institute, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA.
Proc Natl Acad Sci U S A. 1998 Sep 1;95(18):10443-8. doi: 10.1073/pnas.95.18.10443.
The crystal structure of human endostatin reveals a zinc-binding site. Atomic absorption spectroscopy indicates that zinc is a constituent of both human and murine endostatin in solution. The human endostatin zinc site is formed by three histidines at the N terminus, residues 1, 3, and, 11, and an aspartic acid at residue 76. The N-terminal loop ordered around the zinc makes a dimeric contact in human endostatin crystals. The location of the zinc site at the amino terminus, immediately adjacent to the precursor cleavage site, suggests the possibility that the zinc may be involved in activation of the antiangiogenic activity following cleavage from the inactive collagen XVIII precursor or in the cleavage process itself.
人内皮抑素的晶体结构揭示了一个锌结合位点。原子吸收光谱表明，锌是溶液中人和鼠内皮抑素的组成成分。人内皮抑素的锌位点由N端的三个组氨酸（第1、3和11位残基）以及第76位残基处的一个天冬氨酸形成。围绕锌排列的N端环在人内皮抑素晶体中形成二聚体接触。锌位点位于氨基末端，紧邻前体切割位点，这表明锌可能参与从无活性的胶原蛋白XVIII前体切割后抗血管生成活性的激活，或者参与切割过程本身。
