title: Design, purification and assessment of GRP78 binding peptide-linked Subunit A of Subtilase cytotoxic for targeting cancer cells.
abstract: Targeted therapies for cancer, especially the malignant cancer, are always restricted by the deficiency of tumor-specific drug delivery methods. Subtilase cytotoxic is a virulent cytotoxin, and the subunit A (SubA) of it is able to destroy the structure of glucose-regulated protein 78 (GRP78) to induce cell apoptosis, and to be expected as anti-cancer drugs, however, the ubiquitous receptor of subunit B of Subtilase cytotoxic (SubB) restricts its application on cancer therapy.
  
  
  
  The present study constructed and expressed a fusion protein of GBP-SubA in E. coli Rosetta (DE3) system, in which the subunit B of Subtilase cytotoxic was replaced by GRP78 binding peptide (GBP). The fusion protein was expressed in inclusion body form. Subsequently, the denaturation/renaturation process and Ni-column purification were performed. Our data indicated the purified GBP-SubA could bind GRP78 existed on cancer cell surface specifically, internalize into cells to inactivate intracellular GRP78 and induce apoptosis. Moreover, the apoptosis induction effect of GBP-SubA was enhanced obviously along with the increased cancer cell surface GBP78.
  
  
  
  It indicates that the recombinant GBP-SubA possesses the dual functions of GBP and SubA to induce cancer cell apoptosis specifically, revealing that GBP-SubA holds important implications for developing as an anti-cancer peptide drug. A schematic representation of the construction and function of GBP-SubA.
authors: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan, 030006, China.|School of Life Science, Shanxi University, Taiyuan, 030006, China.
authors: Lichao
authors: L
authors: Zhang
authors: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan, 030006, China.
authors: Zongwei
authors: Z
authors: Li
authors: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan, 030006, China.
authors: Tonglin
authors: T
authors: Shi
authors: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan, 030006, China.
authors: Xiaoqin
authors: X
authors: La
authors: School of Life Science, Shanxi University, Taiyuan, 030006, China. lhq922@hotmail.com.
authors: Hanqing
authors: H
authors: Li
authors: Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan, 030006, China. lzy@sxu.edu.cn.|College of Life Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China. lzy@sxu.edu.cn.
authors: Zhuoyu
authors: Z
authors: Li
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D003603:Cytotoxins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D000091342:Endoplasmic Reticulum Chaperone BiP; D029968:Escherichia coli Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000493:pharmacokinetics; D006360:Heat-Shock Proteins / Q000235:genetics / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D009374:Neoplasms, Experimental / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000494:pharmacology; D013381:Subtilisins / Q000008:administration & dosage* / Q000235:genetics / Q000493:pharmacokinetics; D016896:Treatment Outcome
chemical_list: D003603:Cytotoxins; D000091342:Endoplasmic Reticulum Chaperone BiP; D029968:Escherichia coli Proteins; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; D013381:Subtilisins; C527234:subtilase cytotoxin, E coli
keywords: Apoptosis; Cancer; GRP78 binding peptide; Glucose-regulated protein 78; Subunit A of Subtilase cytotoxic