title: Silk sericin-insulin bioconjugates: synthesis, characterization and biological activity.
abstract: When silk fiber derived from Bombyx mori was subjected to degumming treatments twice in water and subsequent degraded processing in slightly alkaline aqueous solution under high-temperature and high-pressure, the water-soluble silk sericin peptides (SS) with different molecular mass from 10 to 70 kDa were obtained. The sericin peptides could be conjugated covalently with insulin alone with cross-linking reagent glutaraldehyde. The physicochemical properties of the silk sericin-insulin (SS-Ins) conjugates were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The biological activities of SS-Ins bioconjugates were investigated in vitro and in vivo. The results in human serum in vitro indicated that the half-life of the synthesized SS-Ins derivatives was 2.3 and 2.7 times more than that of bovine serum albumin-insulin (BSA-Ins) conjugates and intact insulin, respectively. The pharmacological activity of SS-Ins bioconjugates lengthened to 21 h in mice in vivo, which was over 4 times longer than that of the native insulin. The immunogenicity of silk sericin and the antigenicity of SS-Ins derivatives were not observed in both rabbits and mice. The bioconjugation of insulin with silk sericin protein evidently improved both physicochemical and biological stability of the polypeptide.
authors.affiliation: Silk Biotechnology Laboratory, School of Life Science, Soochow University, Dushuhu Higher Education Down, Suzhou 215123, PR China. yqzhang@public1.sz.js.cn
authors.forename: Yu-Qing
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.forename: Yun-Yue
authors.initials: YY
authors.lastname: Xia
authors.forename: Wei-De
authors.initials: WD
authors.lastname: Shen
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Mao
authors.forename: Ren-Yu
authors.initials: RY
authors.lastname: Xue
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D012831:Bombyx; D002626:Chemistry, Pharmaceutical; D003432:Cross-Linking Reagents / Q000737:chemistry; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D004355:Drug Stability; D005976:Glutaral / Q000737:chemistry; D007004:Hypoglycemic Agents / Q000138:chemical synthesis* / Q000276:immunology / Q000494:pharmacology; D066298:In Vitro Techniques; D019476:Insect Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D007328:Insulin / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000276:immunology / Q000494:pharmacology; D008297:Male; D051379:Mice; D008970:Molecular Weight; D011817:Rabbits; D047030:Sericins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D012710:Serum Albumin, Bovine / Q000737:chemistry; D047011:Silk / Q000737:chemistry*
chemical_list: D001786:Blood Glucose; D003432:Cross-Linking Reagents; D007004:Hypoglycemic Agents; D019476:Insect Proteins; D007328:Insulin; D047030:Sericins; D047011:Silk; D012710:Serum Albumin, Bovine; D005976:Glutaral