Recombinant human brain myelin basic protein and its antibody preparation

Ji LIU; Ruohan WANG; Yu LIU; Junjie CHEN

ABSTRACT

BACKGROUND:

Central nervous system (CNS) myelin is made up of 70% lipids and 30% proteins with human brain myelin basic protein (hMBP) constituting 1/3 of the proteins. MBP is a family of proteinswith four isoforms only in human brain.

OBJECTIVE:

To investigate the expression of MBP and its immunological function.

DESIGN:

Single sample study.

SETTING:

Department of Biochemistry and Molecule Biology, Huaxi College of Priclinical Medicine and Forensic Medicine, Sichuan University. MATERIALS This experiment was conducted at Department of Bio chemistry and Molecule Biology, Huaxi College of Priclinical Medicine and Forensic Medicine, Sichuan University from August 2003 to March 2004. Relative molecular weight was 215000 hMBP cDNA clone pGEMP,prokaryotic expression recombinant vector pGEX-5T, T4 DNA Ligase,calf intestine alkaline phosphates, X-gal, IPTG, 123 Ladder (BRL), nitrocellu lose ,4-chloro-1-Naphthol;MBP and Anti- MBP ELISA kit.

INTERVENTIONS:

①hBMP gene cDNA clone segment was digested with EcoR1 and BamH1; ②Construction and transformation of the recombinant expression vector p5TMP; ③ The growth and induced expression of the recombinant expression vector transformed bacteria; ④ Preparation of the antibody of recombinant hMBP. MAIN OUTCOME

MEASURES:

① Detection and identification of the expressed protein product; ② Detection and identification of hMBP anti body.

RESULTS:

① Screening and identification of recombinant MBP The 4 999 bp pGEX-5T DNA and 557 bp MBP inserted fragment were obtained, indicating that the white colonies contained recombinant expression plasmid of exogenous DNA; ② A dense band disappeared from the control plasmid while a new special polypeptide band with apparent molecular weight 42 000 was detected in recombinant cell lysate; ③After 5 subcutaneous injections, antibody was obtained at 116 titer. The specificity of the antibody to MBP was confirmed.

CONCLUSION:

Compared with the original expression vector, the new constructed expression vector containing 215 000 MBP exons Ⅰ-Ⅶ coding sequence was not only without the coding area defects of 34 bp in 5' sequence but also expressed more highly in prokaryote obviously. In addition, the recombinant MBP antibody prepared successfully.