Structural comparison of recombinant human macrophage colony stimulating factor beta and a partially reduced derivative using hydrogen deuterium exchange and electrospray ionization mass spectrometry.
Hydrogen deuterium exchange, monitored by electrospray ionization mass spectrometry, has been employed to characterize structural features of a derivative of recombinant human macrophage colony stimulating factor beta (rhm-CSFbeta) in which two of the nine disulfide bridges (Cys157/Cys159-Cys'157/Cys'159) were selectively reduced and alkylated. Removal of these two disulfide bridges did not affect the biological activity of the protein. Similarities between CD and fluorescence spectra for rhm-CSFbeta and its derivative indicate that removing the disulfide bonds did not strongly alter the overall three-dimensional structure of rhm-CSFbeta. However, differences between deuterium exchange data of the intact proteins indicate that more NHs underwent fast deuterium exchange in the derivative than in rhm-CSFbeta. Regions located near the disulfide bond removal site were shown to exhibit faster deuterium exchange behavior in the derivative than in rhm-CSFbeta.
Zhang
Y H
YH
Department of Chemistry, Oregon State University, Corvallis, Oregon 97330, USA.
Yan
X
X
Maier
C S
CS
Schimerlik
M I
MI
Deinzer
M L
ML
D000595:Amino Acid Sequence; D002460:Cell Line; D002942:Circular Dichroism; D003903:Deuterium; D004220:Disulfides / Q000737:chemistry; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010084:Oxidation-Reduction; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D013050:Spectrometry, Fluorescence
D004220:Disulfides; D011994:Recombinant Proteins; D016173:Macrophage Colony-Stimulating Factor; D003903:Deuterium