title: Imidazole as a catalyst for in vitro refolding of enhanced green fluorescent protein.
abstract: Imidazole is a reagent widely used in protein purifying processes. Here, we reveal a novel chaperone-like activity for imidazole using enhanced green fluorescent protein (EGFP) as a model protein. Experimental results showed that imidazole acted as an effective catalyst for refolding of the chemically denatured EGFP and suppressor for the heat-induced aggregation of EGFP. The refolding kinetics was determined in real time. Both the recovering yield and refolding rate of denatured EGFP in the presence of imidazole were increased. The studies on elucidating the mechanism show that imidazole may catalyze the prolyl cis/trans isomerization and the possible mechanism was discussed. To our knowledge, there are no data on the effect of imidazole on protein folding. Considering the prolyl isomerization is the rate-limited step for refolding of most proteins and aggregation is a universal serious problem for biotechnology, imidazole thus represents a previous unknown type of protein-folding catalyst.
authors.affiliation: College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Ruina
authors.initials: R
authors.lastname: Shi
authors.forename: Qiong
authors.initials: Q
authors.lastname: Pan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Guan
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Hua
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Meiping
authors.initials: M
authors.lastname: Zhao
authors.forename: Yuanzong
authors.initials: Y
authors.lastname: Li
mesh_terms: D002384:Catalysis; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D011489:Protein Denaturation; D017510:Protein Folding
chemical_list: D007093:Imidazoles; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C029899:imidazole