Cloning, Soluble Expression, and Production of Recombinant Antihypertensive Peptide Multimer (AHPM-2) in Escherichia coli for Bioactivity Identification

Shengqi      Rao; Zhenzhen      Xu; Yujie      Su; Junhua      Li; Jun      Sun; Yanjun      Yang

Abstract

Recombinant antihypertensive peptide multimer (AHPM-2, 8kDa/68AA), a new designed polypeptide with potential antihypertensive effect in vivo, is composed of 15 low-molecular-weight antihypertensive peptides tandemly linked up according to the restriction sites of gastrointestinal proteases. After gene optimization, the DNA fragment encoding AHPM-2 was chemically synthesized, cloned into the pET32a, and successfully expressed in E.coli, above 90% in a soluble form. After chromatographic purification, the expressed fusion protein Trx-AHPM-2 was subject to the simulated gastrointestinal digestion, and the hydrolysate showed potent ACE inhibitory activity with an IC50 value of 4.5±0.3 ìg ml-1. The active fragments from the AHPM-2 were identified by UPLC-MS/MS. This method will be useful in obtaining an appreciable quantity of recombinant AHP at low cost, and the intact AHPM-2 is expected to be developed into functional food for preventing hypertension as well as for therapeutic.

Keywords: Antihypertensive peptide, antihypertensive peptide multimer, design, expression, Escherichia coliAntihypertensive peptide, antihypertensive peptide multimer, design, expression, Escherichia coli