Crystallization and preliminary X-ray analysis of insect antifreeze protein from the beetle Tenebrio molitor.
Hyperactive antifreeze protein from the beetle Tenebrio molitor (TmAFP) was produced in Escherichia coli and purified by gel-permeation chromatography and HPLC. An iodinated derivative was prepared by incubating the 8.5 kDa TmAFP with N-iodosuccinimide. Native and iodinated TmAFP produced two different crystal forms when crystallized using the hanging-drop vapor-diffusion technique. Native crystals were rectangular plates that diffracted to approximately 2.5 A resolution. They were monoclinic and belonged to the space group P2(1), with unit-cell dimensions a = 38.4, b = 73.4, c = 59.3 A, beta = 97.0 degrees. Crystals of iodinated TmAFP formed elongated hexagons that allowed data to be collected to approximately 1.4 A. These crystals belonged to the space group P6(1) (or P6(5)), with unit-cell dimensions a = 73.85, b = 73.85, c = 53.15 A. There were two molecules per asymmetric unit, which corresponds to V(m) = 2.46 A(3) Da(-1) and 51% solvent content. A twofold non-crystallographic symmetry was evident from self-rotation calculations.
Liou
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Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada.
Davies
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PL
Jia
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D000818:Animals; D021301:Antifreeze Proteins; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli; D006023:Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification; D019476:Insect Proteins / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification; D013712:Tenebrio / Q000737:chemistry*
D021301:Antifreeze Proteins; D006023:Glycoproteins; D019476:Insect Proteins; D011993:Recombinant Fusion Proteins