Abstract

A novel prokaryotic expression vector pGEX-6T was designed for high-level expression of recombinant fusion protein with a histidine-hexapeptide and glutathione- S-transferase at its N-terminus and the recombinant human preproinsulin at its C-terminus. Efficiency of expression was investigated in the Escherichia coli strain CAG456. The synthesized protein was sequestered in an insoluble form in inclusion bodies and was purified to homogeneity by one-step affinity chromatography based on the specific complex formation of the histidine-hexapeptide and a chelating matrix which was charged with Ni 2+ ions. The antigenic nature of the purified recombinant preproinsulin fusion protein was evaluated by ELISA screening for insulin autoantibodies in selected sera from patients with recent-onset type 1 (insulin-dependent) diabetes mellitus classified by the existence of additional autoantibodies reactive against glutamic acid decarboxylase. 14% of the tested sera ( n=43) conttained insulin autoantibodies which strongly recognized the recombinant human preproinsulin. Comparable measurements with both recombinant human preproinsulin and mature insulin suggested that the observed autoantigenicity of preproinsulin was mediated by the C-peptide or/and signal peptide.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.