Processing the nonstructural polyproteins of Sindbis virus: study of the kinetics in vivo by using monospecific antibodies.

摘要: Plasmids were constructed which contained a large portion of each the four nonstructural genes Sindbis virus fused to N-terminal two-thirds trpE gene Escherichia coli. The quantity fusion protein induced from cells containing these plasmids was subsequently used as an antigen generate polyclonal antisera in rabbits. Each antiserum specific for corresponding and allowed ready identification precursors sequences two or more proteins. These determine stability mature proteins examine kinetics processing their respective vivo. Pulse-chase experiments showed that precursor P123 is cleaved with half-life approximately 19 min produce P12 nsP3; then 9 nsP1 nsP2. Thus, although rate cleavage between nsP2 faster than nsP3, latter must occur first therefore rate-limiting step. at P34 chased suggests nsP3 nsP4 last occur; however regulation function virus-infected may be even complex previously thought. products (and nsP4) are relatively stable; however, unstable, about 1 h, appears modified heterodisperse, higher-molecular-mass forms. In general, schemes by Semliki Forest appear very similar, major difference being most results termination opal condon, whereas required.