Tsunemoto Kazunobu, Osatomi Kiyoshi, Nozaki Yukinori, Hara Kenji, Ishihara Tadashi
Graduate School of Science and Technology, Nagasaki University, Bunkyo, Nagasaki, Nagasaki 852-8521, Japan.
Comp Biochem Physiol B Biochem Mol Biol. 2004 Jan;137(1):107-14. doi: 10.1016/j.cbpc.2003.10.012.
Purified cathepsin L from carp, Cyprinus carpio, consists of a 28 kDa single-chain form that is different from the 24 and 5 kDa mammalian two-chain form. We cloned cathepsin L from carp hepatopancreas. The sequence consisted of a 1490 bp cDNA and a 1014 bp open reading frame, encoding a deduced protein of 337 amino acids that is likely processed to an active enzyme (single-chain form) with 222 amino acids. Its similarity to other types of vertebrate cathepsin L is less than 69%. Mammalian cathepsin L is further processed to a two-chain form, but possibly this is not the case with carp cathepsin L: the P1 site where cleavage occurred in the two-chain form of mammalian cathepsin L contains a serine, while carp cathepsin L processes a valine. Therefore, carp cathepsin L may have a different mechanism of action from mammalian cathepsin L.
从鲤鱼（Cyprinus carpio）中纯化得到的组织蛋白酶L由一种28 kDa的单链形式组成，这与24 kDa和5 kDa的哺乳动物双链形式不同。我们从鲤鱼肝胰脏中克隆了组织蛋白酶L。该序列由一个1490 bp的cDNA和一个1014 bp的开放阅读框组成，编码一个推测的337个氨基酸的蛋白质，该蛋白质可能被加工成具有222个氨基酸的活性酶（单链形式）。它与其他类型的脊椎动物组织蛋白酶L的相似度小于69%。哺乳动物组织蛋白酶L会进一步加工成双链形式，但鲤鱼组织蛋白酶L可能并非如此：在哺乳动物组织蛋白酶L的双链形式中发生切割的P1位点含有一个丝氨酸，而鲤鱼组织蛋白酶L在该位点是缬氨酸。因此，鲤鱼组织蛋白酶L的作用机制可能与哺乳动物组织蛋白酶L不同。
