Saito T, Kumazaki T, Ochiai H
Department of Biology, Faculty of Science, Hokkaido University, Japan.
J Biol Chem. 1994 Nov 18;269(46):28798-802.
The 64-kDa membrane-bound glycoprotein of the cellular slime mold Polysphondylium pallidum (referred to as gp64), seems to be implicated in cell-cell adhesion. Previously we have isolated a full-length gp64 cDNA, determined its nucleotide sequence, and found that all cysteine residues in the protein are involved in the formation of disulfide bonds. The disulfide arrangement of the 36 cysteines in gp64 was established by analysis of proteolytically cleaved protein and sequence analysis of cystine-containing fragments. Since gp64 has 36 Cys residues, 18 disulfide bonds must exist and the positions of 15 of them were determined. The 15 disulfide bonds in gp64 constitute five characteristic, so-called Sushi domains. In a Sushi domain, the first Cys in a sequence is connected to the third one and the second Cys to the fourth one. This is the first report describing the presence of Sushi domains in a cellular slime mold protein. From these data, gp64 appears to be distinct from all other previously described cell-adhesion proteins.
细胞黏菌苍白聚孢霉的64 kDa膜结合糖蛋白（称为gp64）似乎与细胞间黏附有关。此前我们已分离出全长gp64 cDNA，确定了其核苷酸序列，并发现该蛋白中的所有半胱氨酸残基都参与了二硫键的形成。通过对蛋白酶裂解产物的分析和含胱氨酸片段的序列分析，确定了gp64中36个半胱氨酸的二硫键排列方式。由于gp64有36个半胱氨酸残基，必然存在18个二硫键，其中15个的位置已确定。gp64中的15个二硫键构成了五个特征性的所谓寿司结构域。在一个寿司结构域中，序列中的第一个半胱氨酸与第三个相连，第二个半胱氨酸与第四个相连。这是首次报道在细胞黏菌蛋白中存在寿司结构域。从这些数据来看，gp64似乎与之前描述的所有其他细胞黏附蛋白都不同。
