Solubilization of Trichoplusia ni granulosis virus proteinic crystal: I. Kinetics

Methods for the solubilization of an insect granulosis virus capsule from Trichoplusia ni were studied using turbidity measurements. The solubilization in the solvents employed was most strongly influenced by pH. Various alcohols and hydrogen bond cleaving agents also enhanced solubilization. The most effective solvent tested at pH′s close to neutrality was 60% n-propanol saturated with guanidine. HCl. The effectiveness of this solvent was minimal at pH 5.2. It was shown that the time courses of the solubilization were generally composed of three phases. A plot of the third phase levels versus pH indicated a normal distribution of those capsules or capsular fragments in resisting solubilization. Validity of the calculation of rate constants for the dissociation reaction in the second phase was discussed. Logarithm of the rate constant showed a linear relationship with the reciprocal of absolute temperature. The activation energy for the dissociation calculated from this relationship using the Arrhenius equation indicated that hydrophobic and hydrogen binding forces play the major roles for the stability of the crystalline structure of the capsular protein. Inic binding forces were estimated to be of minor importance.