Determination of protein composition and host-derived proteins of Bombyx mori nucleopolyhedrovirus by 2-dimensional electrophoresis and mass spectrometry.
OBJECTIVE
The occlusion-derived form of baculovirus is specially adapted for primary infection of host midgut epithelial cells. The virion contains proteins essential for host-range determination and initiation of infection. Determination of protein composition of the occlusion-derived virus (ODV) will help us to understand this virion's infection mechanism.


METHODS
We obtained the ODV virion of Bombyx mori nucleopolyhedrovirus (BmNPV) by sucrose density gradient centrifugation, and used SDS-PAGE, 2-dimensional electrophoresis and mass spectrometry to identify--for the first time--proteins present within or associated with the ODV virion.


RESULTS
20 proteins, including 16 major proteins of the virion encoded by BmNPV and 4 proteins of the silkworm, were identified with confidence.


CONCLUSIONS
Three BmNPV proteins (orf40, P95 and protein tyrosine phosphatase), which had not been detected as components of ODV previously, were identified in this study. We propose that the host-derived proteins may be important for the assembly and maturation of the ODV capsid.
Liu
Xiaoyong
X
Institute of Life Sciences, Jiangsu University, Zhenjiang, PR China.
Chen
Keping
K
Cai
Keya
K
Yao
Qin
Q
D000818:Animals; D012831:Bombyx / Q000821:virology*; D002499:Centrifugation, Density Gradient / Q000379:methods; D015180:Electrophoresis, Gel, Two-Dimensional; D019476:Insect Proteins / Q000032:analysis*; D013058:Mass Spectrometry; D017924:Nucleopolyhedroviruses / Q000737:chemistry*; D020543:Proteome / Q000032:analysis*; D014771:Virion / Q000737:chemistry / Q000302:isolation & purification
D019476:Insect Proteins; D020543:Proteome