Lin C W, Chiou S H
Laboratory of Crystallin Research, National Taiwan University, Taipei.
Biochem Int. 1992 Jun;27(1):173-8.
S-crystallin is a major lens protein present in the octopus and squid of Cephalopods. To facilitate the cloning of the protein, cDNA was constructed from the poly(A)+RNA of octopus lenses, and amplification by polymerase chain reaction (PCR) was carried out with two primers designed according to the 5'- and 3'-coding regions of S-crystallin gene. Sequencing two of 15 positive clones obtained shows 37-44% similarity in nucleotide and 23-30% similarity in amino acid sequences as compared with mammalian glutathione S-transferases (GST), revealing that S-crystallins exist as a multigene family and probably derived from GST by gene duplication and subsequent mutational base replacements.
S-晶体蛋白是头足类动物章鱼和鱿鱼晶状体中的一种主要晶状体蛋白。为便于该蛋白的克隆，从章鱼晶状体的聚腺苷酸加尾RNA构建了互补DNA（cDNA），并使用根据S-晶体蛋白基因的5'-和3'-编码区设计的两种引物通过聚合酶链反应（PCR）进行扩增。对获得的15个阳性克隆中的两个进行测序，结果显示，与哺乳动物谷胱甘肽S-转移酶（GST）相比，其核苷酸相似性为37%-44%，氨基酸序列相似性为23%-30%，这表明S-晶体蛋白以多基因家族形式存在，可能是通过基因复制和随后的突变碱基替换从GST衍生而来。
