人Cathepsin B / CTSB蛋白, His Tag

Human Cathepsin B / CTSB Protein, His Tag (MALS verified)

分子别名（Synonym）

CTSB,CPSB,APPS

表达区间及表达系统（Source）

Human Cathepsin B, His Tag (CTB-H5222) is expressed from human 293 cells (HEK293). It contains AA Arg 18 - Ile 339 (Accession # P07858-1 (L26V)).

Predicted N-terminus: Arg 18 & Leu 80

蛋白结构（Molecular Characterization）

This protein carries a polyhistidine tag at the C-terminus. The Human Cathepsin B will be further processed into mature form (Leu 80-Ile 339). The protein has a calculated MW of 36.7 kDa (pro-form) and 29.5 kDa (mature-form). The protein migrates as 30-32 kDa and 38-43 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) due to glycosylation.

内毒素（Endotoxin）

Less than 1.0 EU per μg by the LAL method / rFC method.

纯度（Purity）

>95% as determined by SDS-PAGE.

>90% as determined by SEC-MALS.

制剂（Formulation）

Lyophilized from 0.22 μm filtered solution in 50 mM Tris, 150 mM NaCl, pH8.0 with trehalose as protectant.

Contact us for customized product form or formulation.

重构方法（Reconstitution）

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

存储（Storage）

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

This product is stable after storage at:

-20°C to -70°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

背景介绍

组织蛋白酶B（CTSB）亦称APP分泌酶（APPS）及CPSB，属肽酶C1家族酶蛋白。该酶以前酶原形式合成，经信号肽切除后，无活性的酶原经修饰（包括前结构域切除）转化为活性酶。其催化活性包括：广谱水解多肽键；特异性切割小分子底物中的-Arg-Arg-|-Xaa键（此特性区别于组织蛋白酶L）；除内肽酶活性外，还具有肽酰二肽酶活性，可释放C端二肽。作为巯基蛋白酶，CTSB/CPSB参与细胞内蛋白质降解与代谢更新，并在肿瘤侵袭转移中发挥重要作用。该酶过表达与食管腺癌等多种肿瘤的发生发展密切相关。