Chen J M, Dando P M, Stevens R A, Fortunato M, Barrett A J
MRC Peptidase Laboratory, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK.
Biochem J. 1998 Oct 1;335 ( Pt 1)(Pt 1):111-7. doi: 10.1042/bj3350111.
Legumain, a recently discovered mammalian cysteine endopeptidase, was found in all mouse tissues examined, but was particularly abundant in kidney and placenta. The distribution in subcellular fractions of mouse and rat kidney showed a lysosomal localization, and activity was detectable only after the organelles were disrupted. Nevertheless, ratios of legumain activity to that of cathepsin B differed considerably between mouse tissues. cDNA encoding mouse legumain was cloned and sequenced, the deduced amino acid sequence proving to be 83% identical to that of the human protein [Chen, Dando, Rawlings, Brown, Young, Stevens, Hewitt, Watts and Barrett (1997) J. Biol. Chem. 272, 8090-8098]. Recombinant mouse legumain was expressed in human embryonic kidney 293 cells by use of a vector containing a cytomegalovirus promoter. The recombinant enzyme was partially purified and found to be an asparagine-specific endopeptidase closely similar to naturally occurring pig kidney legumain.
豆荚蛋白酶是最近发现的一种哺乳动物半胱氨酸内肽酶，在所检测的所有小鼠组织中均有发现，但在肾脏和胎盘中含量尤为丰富。小鼠和大鼠肾脏亚细胞组分中的分布显示其定位于溶酶体，且只有在细胞器被破坏后才能检测到活性。然而，小鼠组织中豆荚蛋白酶活性与组织蛋白酶B活性的比值差异很大。编码小鼠豆荚蛋白酶的cDNA被克隆并测序，推导的氨基酸序列与人类蛋白的氨基酸序列有83%的同源性[Chen, Dando, Rawlings, Brown, Young, Stevens, Hewitt, Watts和Barrett(1997) J. Biol. Chem. 272, 8090 - 8098]。重组小鼠豆荚蛋白酶通过使用含有巨细胞病毒启动子的载体在人胚肾293细胞中表达。该重组酶经过部分纯化，发现是一种天冬酰胺特异性内肽酶，与天然存在的猪肾豆荚蛋白酶非常相似。
