The refolding of hen egg white riboflavin-binding protein: effect of protein disulphide isomerase on the reoxidation of the reduced protein.
Hen egg white riboflavin-binding protein (RfBP) contains nine disulphide bonds. Provided these remain intact, the refolding of RfBP after incubation in 6 M guanidinium chloride is highly efficient with at least 95% of the binding activity regained within 3 min. Kinetic studies indicate that this regain consists of at least two phases. When the disulphide bonds of RfBP are reduced, reoxidation using a mixture of oxidized and reduced glutathione leads to less than 5% recovery of activity. However, if protein disulphide isomerase (PDI; EC 5.3.4.1) is present during the reoxidation nearly 50% activity can be regained, suggesting that PDI may play an important role in the maturation of RfBP in vivo.
McClelland
D A
DA
Department of Biological and Molecular Sciences, University of Stirling, Scotland, UK.
McLaughlin
S H
SH
Freedman
R B
RB
Price
N C
NC
D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D002645:Chickens; D002942:Circular Dichroism; D004220:Disulfides / Q000378:metabolism; D004529:Egg White; D005260:Female; D005978:Glutathione / Q000378:metabolism; D019791:Guanidine; D006146:Guanidines; D007535:Isomerases / Q000378:metabolism*; D007700:Kinetics; D026901:Membrane Transport Proteins; D010084:Oxidation-Reduction; D011489:Protein Denaturation; D019704:Protein Disulfide-Isomerases; D017510:Protein Folding; D013050:Spectrometry, Fluorescence
D002352:Carrier Proteins; D004220:Disulfides; D006146:Guanidines; D026901:Membrane Transport Proteins; C019079:riboflavin-binding protein; D007535:Isomerases; D019704:Protein Disulfide-Isomerases; D005978:Glutathione; D019791:Guanidine