In this paper, Attacus ricini nuclear polyhedrosis virus (ArNPV) was studied. The molecular weight and pi of polyhedrin and structural polypeptides were determined by vertical slab SDS-PAGE and thin-layer isoelectrofocusing electrophoresis. The restriction pattern of ArNPV DNA was assayed by 5 restriction endonucleases. The observation methods and the results on super-microstructure of necleopolyhedrosis of ArNPV were introduced in the paper. And the super-microstructure was also described. Using ultraviolet spectrum, fluorescence spectrum and Fourier-transform infrared spectrum, the secondary structure of polyhedrin was studied. Amide I band was observed by deconvolution. According to the amino-acid residue sequence, the secondary structure of polyhedrin was predicted by software Antheprot.Assayed by vertical slab SDS-PAGE, ArNPV polyhedrin contained a single polypeptide with molecular weight of 29kD; virion contained 16 structural polypeptides with molecular weight range from 15.2~97.5kD. The pi of polyhedrin was pH5.8 and the pi of structural polypeptides were pH4.8 - 6.4. Digestion of ArNPV-DNA with restriction endonucleases, BamH I -, EcoR I Hind IIL Pst I and BglII, resulted in 2 14x 10x9 and 8 fragments, respectively, and molecular weight of ArNPV-DNA was 76.9 X ICfD. Scanning electron microscope showed that the ArNPV inclusion bodies were irregular polyhedra with different sizes. The average diameter of the polyhedra was 2.4 H m. Many rod-shaped virus bundles which measured from 320~417nmX 83-227 nm were released from the polyhedra when they were decomposed by alkali. The size of the naked nucleocapsids was 320nm X 83nm. Numbers of nucleocapsids observed in an envelope in their cross sections ranged from 1 to 10, and the frequencies at 1 nucleocapsid was significantly higher than the others, almost 80.04% of the all. Differences in the arrangement patterns of nucleocapsids were existed within the envelopes of ArNPV. The analysis of polyhedrin structure with spectrophotometer methods showed that a -helix and P -sheet structure all consisted in the secondary tincture of polyhedrin. The software analysis showed that polyhedrinwas composed of 29% a -helix, 22% 0 -sheet, 22% 3 -turn and 27% coil. There were two hydrophilic regions , two hydrophobic regions and no transmembrane rigion in the polyhedrin molecule. |