Surfactant-induced amorphous aggregation of tobacco mosaic virus coat protein: a physical methods approach.
The interactions of non-ionic surfactant Triton X-100 and the coat protein of tobacco mosaic virus, which is an established model for both ordered and non-ordered protein aggregation, were studied using turbidimetry, differential scanning calorimetry, isothermal titration calorimetry, and dynamic light scattering. It was found that at the critical aggregation concentration (equal to critical micelle concentration) of 138 x 10(-6) M, Triton X-100 induces partial denaturation of tobacco mosaic virus coat protein molecules followed by protein amorphous aggregation. Protein aggregation has profound ionic strength dependence and proceeds due to hydrophobic sticking of surfactant-protein complexes (start aggregates) with initial radii of 46 nm. It has been suggested that the anionic surfactant sodium dodecyl sulfate forms mixed micelles with Triton X-100 and therefore reverses protein amorphous aggregation with release of protein molecules from the amorphous aggregates. A stoichiometric ratio of 5 was found for Triton X-100-sodium dodecyl sulfate interactions.
Panyukov
Yuliy V
YV
A.N. Belozersky Institute of Physico-Chemical Biology and Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow 119992, Russia. panyukov@belozersky.msu.ru
Nemykh
Maria A
MA
Dobrov
Eugeny N
EN
Drachev
Vladimir A
VA
D002152:Calorimetry, Differential Scanning; D036022:Capsid Proteins / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods; D008823:Micelles; D009391:Nephelometry and Turbidimetry; D017830:Octoxynol / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014027:Tobacco Mosaic Virus / Q000737:chemistry*
D036022:Capsid Proteins; D008823:Micelles; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D017830:Octoxynol