title: Glu659Leu substitution of recombinant HIV fusion inhibitor C52L induces soluble expression in Escherichia coli with equivalent anti-HIV potency.
abstract: The C-peptides used to prevent HIV infection, such as T20 and C34, are chemically synthesized, making them costly drugs. The sensitivity of peptides to protease also restricts their clinical application. We showed previously that C52L, a recombinant peptide produced in bacteria, is a potent anti-HIV C-peptide, although most of the peptide accumulates in inclusion bodies. Here we applied leucine and glutamine scanning mutagenesis to the heptad-repeat of C52L to produce an optimized variant of C52L that is potent and soluble when expressed in bacteria. We present that the substitution of Asn656 and Glu659 with leucine (peptide L14 and L15, respectively) can increase the helical content of this peptide. These substitutions also result in soluble expression. We measured the inhibitory activities of these mutant peptides against laboratory-adapted HIV-1 strains and found that L15 and its parental peptide C52L have equivalent anti-HIV activities. Moreover, L15 was found to be more stable to proteinase K digestion than C52L. Thus, we show that the L15 peptide can be expressed in a soluble state and exhibits potent anti-HIV activity. This peptide may be further developed as an anti-HIV therapeutic and/or microbicide for the prevention of HIV sexual transmission.
authors.affiliation: College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Shufeng
authors.initials: S
authors.lastname: Shang
authors.forename: Suiyi
authors.initials: S
authors.lastname: Tan
authors.forename: Kangbai
authors.initials: K
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Huina
authors.initials: H
authors.lastname: Lin
authors.forename: Shuwen
authors.initials: S
authors.lastname: Liu
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Deng
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002096:C-Peptide / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D023581:HIV Fusion Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015658:HIV Infections / Q000188:drug therapy; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007930:Leucine / Q000235:genetics; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D012995:Solubility
chemical_list: D002096:C-Peptide; D023581:HIV Fusion Inhibitors; D011994:Recombinant Proteins; D007930:Leucine