Mann K, Deutzmann R, Aumailley M, Timpl R, Raimondi L, Yamada Y, Pan T C, Conway D, Chu M L
Max-Planck-Institut für Biochemie, Martinsried, FRG.
EMBO J. 1989 Jan;8(1):65-72. doi: 10.1002/j.1460-2075.1989.tb03349.x.
The whole amino acid sequence of nidogen was deduced from cDNA clones isolated from expression libraries and confirmed to approximately 50% by Edman degradation of peptides. The protein consists of some 1217 amino acid residues and a 28-residue signal peptide. The data support a previously proposed dumb-bell model of nidogen by demonstrating a large N-terminal globular domain (641 residues), five EGF-like repeats constituting the rod-like domain (248 residues) and a smaller C-terminal globule (328 residues). Two more EGF-like repeats interrupt the N-terminal and terminate the C-terminal sequences. Weak sequence homologies (25%) were detected between some regions of nidogen, the LDL receptor, thyroglobulin and the EGF precursor. Nidogen contains two consensus sequences for tyrosine sulfation and for asparagine beta-hydroxylation, two N-linked carbohydrate acceptor sites and, within one of the EGF-like repeats an Arg-Gly-Asp sequence. The latter was shown to be functional in cell attachment to nidogen. Binding sites for laminin and collagen IV are present on the C-terminal globule but not yet precisely localized.
通过从表达文库中分离出的cDNA克隆推导得出了巢蛋白的完整氨基酸序列，并通过肽段的埃德曼降解法确认了约50%的序列。该蛋白质由约1217个氨基酸残基和一个28个残基的信号肽组成。数据通过展示一个大的N端球状结构域（641个残基）、构成杆状结构域的五个表皮生长因子（EGF）样重复序列（248个残基）和一个较小的C端小球（328个残基），支持了先前提出的巢蛋白哑铃模型。另外两个EGF样重复序列打断了N端序列并终止了C端序列。在巢蛋白的某些区域、低密度脂蛋白（LDL）受体、甲状腺球蛋白和EGF前体之间检测到了较弱的序列同源性（25%）。巢蛋白含有两个酪氨酸硫酸化和天冬酰胺β-羟化的共有序列、两个N-连接糖基化受体位点，并且在其中一个EGF样重复序列内有一个精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp）序列。后者已被证明在细胞与巢蛋白的附着中起作用。层粘连蛋白和IV型胶原的结合位点存在于C端小球上，但尚未精确定位。
