Pillai S
Biochem J. 1981 Mar 1;193(3):825-8. doi: 10.1042/bj1930825.
A dimeric glycoprotein, glucose oxidase, was allowed to react with lysine-specific cross-linkers, both when immobilized on a succinoylated lectin matrix at a critically low density and also at a high density in solution. Analysis of the cross-linked complexes thus obtained led to the following inferences with regard to the structure of this protein. (1) Of the 15 lysine residues on each glucose oxidase protomer, none is available on the non-interfacial surfaces. (2) Assuming that this protein possesses C2 symmetry with isologous bonding between subunits, it may be inferred that on each promoter there are at least two lysine clusters along or close to the interprotomeric interface. (3) These "interfacial' lysine residues on each protomer are so oriented that the epsilon-amino groups of lysine residues a and b on protomer 1 "face', and are very close to, the epsilon-amino groups of lysine residues b' and a' respectively on protomer 2. General inferences on the geometry of dimeric proteins derivable from an analysis of the cross-linked complexes obtained (as well as those not seen) by using this low-density matrix cross-linking approach were enumerated. Modified lectin matrices may prove useful in studying the three-dimensional structure of glycoproteins, particularly non-crystallizable oligomers.
一种二聚体糖蛋白——葡萄糖氧化酶，在以极低密度固定在琥珀酰化凝集素基质上时以及在溶液中以高密度时，都与赖氨酸特异性交联剂发生反应。对由此获得的交联复合物的分析得出了关于该蛋白质结构的以下推论。（1）每个葡萄糖氧化酶原聚体上的15个赖氨酸残基中，没有一个位于非界面表面。（2）假设该蛋白质具有C2对称性且亚基之间存在同源键合，可以推断在每个原聚体上，沿着原聚体间界面或靠近该界面至少有两个赖氨酸簇。（3）每个原聚体上这些“界面”赖氨酸残基的取向使得原聚体1上赖氨酸残基a和b的ε-氨基分别“面对”原聚体2上赖氨酸残基b'和a'的ε-氨基，并且与之非常接近。列举了通过使用这种低密度基质交联方法对所获得（以及未观察到）的交联复合物进行分析可得出的关于二聚体蛋白质几何结构的一般推论。修饰的凝集素基质可能被证明在研究糖蛋白，特别是不可结晶的寡聚体的三维结构方面是有用的。
