Time-resolved solution X-ray scattering of tobacco mosaic virus coat protein: kinetics and structure of intermediates

Journal Article · Mon Oct 31 23:00:00 EST 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00422a028· OSTI ID:5980371

Potschka, M; Kock, M H.J.; Adams, M L; Schuster, T M

The kinetics of assembly and disassembly of tobacco mosaic virus coat protein (TMVP) following temperature jumps have been studied by small-angle X-ray scattering and turbidimetry. The structures of the principal aggregates of TMVP oligomers (A protein), intermediate size (helix I) and large size helical rods (helix II), have been characterized by their average radii of gyration of thickness, cross section, and shape obtained from the corresponding regimes of the small-angle scattering pattern. This structural information was obtained within seconds after the temperature-induced initiation of either polymerization or depolymerization and allowed the authors to detect transient intermediates. This methodology made it possible to observe and characterize the structure of a principal intermediate. Taken together with other kinetic information, these data suggest that polymerization of TMVP under virus self-assembly conditions may proceed via a single-layered helical nucleus that contains about 20 subunits. Previous studies have shown that overshoot polymerization of TMVP can occur and result in metastable long helical viruslike rods which subsequently depolymerize and then form short helical rods, depending on the conditions of the final equilibrium state. The longer rods (helix II) are overshoot polymers which form within seconds and contain 17 1/3 subunits per turn (helix IIB), in contrast to the subunit packing arrangement of 16 1/3 subunits per turn found in the shorter helical rods (helix IA). The latter packing arrangement is the one found in TMV. An overall polymerization scheme is proposed for the formation of these two helical forms of TMVP.

• Research Organization: Univ. of Connecticut, Storrs (USA)
• OSTI ID: 5980371
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:22; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
BIOCHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
KINETICS
MICROORGANISMS
ORGANIC COMPOUNDS
PARASITES
POLYMERIZATION
PROTEINS
REACTION KINETICS
SCATTERING
TEMPERATURE EFFECTS
TOBACCO MOSAIC VIRUS
VIRUSES
X-RAY DIFFRACTION