title: Diethylpyrocarbonate modification reveals HisB5 as an important modulator of insulin amyloid formation.
abstract: More than 30 amyloid proteins are reported to be associated with amyloidosis diseases. Studies have implicated histidine may be critically involved in amyloid formation. Here, we used diethylpyrocarbonate (DEPC) modification to obtain a His(B5) mono-ethyloxyformylated insulin (DMI-B(5)). The secondary structure, amyloidogenicity, metal ion interaction, and cytotoxicity of DMI-B(5) and insulin were compared. DMI-B(5) was less prone to aggregation in acidic condition but easier to aggregate at neutral pH. DEPC modification resulted in attenuated inhibitory effect of Zn(2+) on aggregation, whereas DMI-B(5) fibrils induced more severe erythrocytes haemolysis compared to insulin fibrils. This study not only provides a fast new approach for studying the impact of imidazole ring in amyloid formation, but also reveals the critical modulating role of histidine imidazole ring on the amyloidogenicity of insulin.
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Lianqi
authors.initials: L
authors.lastname: Huang
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Gong
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China Wuhan Institute of Biotechnology, Wuhan, Hubei 430075, P.R. China kunhuang2008@hotmail.com.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D058227:Amyloidogenic Proteins / Q000138:chemical synthesis / Q000378:metabolism*; D000686:Amyloidosis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000818:Animals; D004047:Diethyl Pyrocarbonate / Q000737:chemistry* / Q000378:metabolism; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism; D006461:Hemolysis; D007328:Insulin / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000378:metabolism*; D007700:Kinetics; D066263:Protein Aggregation, Pathological / Q000378:metabolism* / Q000473:pathology; D017433:Protein Structure, Secondary; D034421:Sus scrofa
chemical_list: D058227:Amyloidogenic Proteins; D007328:Insulin; D004047:Diethyl Pyrocarbonate
keywords: DMI-B5; amyloidogenicity; haemolysis; metal ions; porcine insulin