Crystallization of a recombinant form of the complete sequence of human gamma-interferon: characterization by small-angle X-ray scattering, mass spectrometry and preliminary X-ray diffraction studies.
The crystallization conditions of a recombinant form of the complete sequence of human gamma-interferon, designated r-hu IFN-gamma (RU 42369), have been determined after studying the behaviour of this protein in solution by small-angle X-ray scattering (SAXS) as a function of pH and salt type. IFN-gamma is difficult to crystallize without truncating at least the last five amino acids of the C-terminus; the SAXS results suggest viable crystallization conditions that led to crystals of r-hu IFN-gamma suitable for X-ray diffraction analysis. The crystals were grown in the presence of ammonium sulfate using vapour-diffusion techniques. The crystals, which diffract to 5 A resolution at best, belong to the primitive tetragonal space group P42(1)2 and have unit-cell parameters a = b = 123.4, c = 93.4 A. The protein contained in these crystals was analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), which verified the presence of the complete amino-acid sequence of r-hu IFN-gamma.
Budayova-Spano
M
M
Centre de Recherche sur les Mécanismes de la Croissance Cristalline, CRMC2-CNRS, Campus de Luminy, Case 913, F-13288 Marseille CEDEX 09, France.
Shepard
W
W
Schoot
B
B
Astier
J P
JP
Veesler
S
S
D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D007371:Interferon-gamma / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D011994:Recombinant Proteins; D007371:Interferon-gamma