Computer-aided modeling of structure stabilizing disulfide bonds in recombinant human interferon-gamma.
We present a general search algorithm for possible insertion sites of disulfide bonds in proteins based on the coordinates of the solved X-ray or NMR structure, allowing the insertion of disulfide bonds with a minimum of conformational tension and backbone rearrangements. The FORTRAN 77 program "Ssuitable' was written for this purpose. This methodological approach was applied to recombinant human interferon-gamma (rhu-IFN-gamma), a cytokine of great pharmaceutical interest with a wide variety of biological activities including antiviral, antiproliferative and immunomodulatory effects. A model based on the C alpha-coordinates obtained from the Brookhaven data base was built. Four different insertion sites were selected in the model, connecting the two subunits of the homodimer. The thermodynamic stability of rhu-IFN-gamma is low, limiting its clinical application. We expect that the insertion of additional new disulfide bonds will enhance the thermodynamic stability as well as protect the protein against proteolytic degradation.
Günther
G
G
Fraunhofer Institut für Toxikologie und Aerosolforschung, Hannover, Germany. guenther@ita.fhg.de
Fechteler
T
T
Villmann
C
C
Zakaria
H
H
Schomburg
D
D
Otto
B
B
D000595:Amino Acid Sequence; D003198:Computer Simulation; D004220:Disulfides / Q000737:chemistry*; D006801:Humans; D007371:Interferon-gamma / Q000737:chemistry*; D008961:Models, Structural; D008969:Molecular Sequence Data; D011994:Recombinant Proteins
D004220:Disulfides; D011994:Recombinant Proteins; D007371:Interferon-gamma