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Castor Silkworm Nuclear Polyhedrosis Virus (attacus Ricini Nuclear Polyhedrosis Virus) Of The Study

Posted on:2003-08-22Degree:MasterType:Thesis
Country:ChinaCandidate:M WuFull Text:PDF
GTID:2193360062996078Subject:Microbiology
Abstract/Summary:PDF Full Text Request
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.
Keywords/Search Tags:Attacus ricini nuclear polyhedrosis virus (ArNPV), polyhedrin, structural polypeptides, super-microstructure, secondary structure
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