title: Refolding of horseradish peroxidase is enhanced in presence of metal cofactors and ionic liquids.
abstract: The effects of various refolding additives, including metal cofactors, organic co-solvents, and ionic liquids, on the refolding of horseradish peroxidase (HRP), a well-known hemoprotein containing four disulfide bonds and two different types of metal centers, a ferrous ion-containing heme group and two calcium atoms, which provide a stabilizing effect on protein structure and function, were investigated. Both metal cofactors (Ca(2+) and hemin) and ionic liquids have positive impact on the refolding of HRP. For instance, the HRP refolding yield remarkably increased by over 3-fold upon addition of hemin and calcium chloride to the refolding buffer as compared to that in the conventional urea-containing refolding buffer. Moreover, the addition of ionic liquids [EMIM][Cl] to the hemin and calcium cofactor-containing refolding buffer further enhanced the HRP refolding yield up to 80% as compared to 12% in conventional refolding buffer at relatively high initial protein concentration (5 mg/ml). These results indicated that refolding method utilizing metal cofactors and ionic liquids could enhance the yield and efficiency for metalloprotein.
authors.affiliation: Department of Biological Engineering, Inha University, Incheon, Republic of Korea.
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Bae
authors.affiliation: Department of Biological Engineering, Inha University, Incheon, Republic of Korea.
authors.forename: Doyoung
authors.initials: D
authors.lastname: Eom
authors.affiliation: Department of Biological Engineering, Inha University, Incheon, Republic of Korea.|Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
authors.forename: Ngoc Lan
authors.initials: NL
authors.lastname: Mai
authors.affiliation: Department of Biological Engineering, Inha University, Incheon, Republic of Korea. ymkoo@inha.ac.kr.
authors.forename: Yoon-Mo
authors.initials: YM
authors.lastname: Koo
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D006427:Hemin / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D052578:Ionic Liquids / Q000494:pharmacology*; D007700:Kinetics; D008670:Metals / Q000737:chemistry; D011487:Protein Conformation; D058849:Protein Refolding / Q000187:drug effects; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014508:Urea / Q000494:pharmacology
chemical_list: D052578:Ionic Liquids; D008670:Metals; D012997:Solvents; D006427:Hemin; D014508:Urea; D006735:Horseradish Peroxidase; D002118:Calcium
keywords: Ionic liquids; Metal cofactor; Peroxidase; Protein refolding; Refolding additive