title: Nano-cage-mediated refolding of insulin by PEG-PE micelle.
abstract: Insulin aggregation has pronounced pharmaceutical implications and biological importance. Deposition of insulin aggregates is associated with type II diabetes and instability of pharmaceutical formulations. We present in this study the renaturation effect of PEG-PE micelle on dithiothreitol (DTT)-denatured insulin revealed by techniques including turbidity assay, circular dichroism (CD), thioflavinT (ThT) binding assay, bis-ANS binding assay, agarose gel electrophoresis and MALDI-TOF MS. The obtained results show that PEG-PE micelle having a hydrophilic nano-cage-like structure in which with a negative charge layer, can capture DTT-induced insulin A and B chains, and block their hydrophobic interaction, thereby preventing aggregation. The reduced insulin A and B chain in the nano-cage are capable of recognizing each other and form the native insulin with yields of ∼30% as measured by hypoglycemic activity analysis in mice. The observed insulin refolding assisted by PEG-PE micelle may be applicable to other proteins.
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; CAS Key Lab for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, No.11 ZhongGuanCun BeiYiTiao, Beijing 100190, China.
authors.forename: Xiaocui
authors.initials: X
authors.lastname: Fang
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; University of the Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China; University of the Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China.
authors.forename: Luoyang
authors.initials: L
authors.lastname: Wang
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Jibing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wei
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China.
authors.forename: Yinjian
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: CAS Key Lab for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, No.11 ZhongGuanCun BeiYiTiao, Beijing 100190, China. Electronic address: wangch@nanoctr.cn.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Protein & Peptide Pharmaceutical Laboratory, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China. Electronic address: weixx@sun5.ibp.ac.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
mesh_terms: D000818:Animals; D004229:Dithiothreitol / Q000494:pharmacology; D057927:Hydrophobic and Hydrophilic Interactions; D007003:Hypoglycemia / Q000139:chemically induced; D007328:Insulin / Q000737:chemistry* / Q000633:toxicity; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008823:Micelles; D049329:Nanostructures; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D066329:Protein Aggregates; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011897:Random Allocation; D055672:Static Electricity; D013552:Swine
chemical_list: D007328:Insulin; D008823:Micelles; D010714:Phosphatidylethanolamines; D066329:Protein Aggregates; D011092:Polyethylene Glycols; D004229:Dithiothreitol
keywords: DTT; Insulin; Nano-cage; Negative charge layer; PEG-PE micelle; Refolding