Light scattering methods have been used to calculate the mean hydrodynamic radius of protein aggregates and to characterize molecular distribution of protein aggregates.
At pH 6.5, the hydrodynamic radius of protein polymers increased with increasing calcium concentration, while the opposite trend was observed at pH 8.5.
Factors influencing the diffusion coefficient of a protein in a membrane include the radius of the proteins membrane spanning region and the viscosity of the membrane among other factors.
The results showed that IN (14.2 kDa) has a larger hydrodynamic radius (24 Å) than the corresponding molecular mass of globular protein {19 Å, calculated by the equation: log RNS =−0.204+0.357×log M, where RNS is the expected Stokes radius of globular proteins [ 23]}.
In further support of the occurrence of some residual structure, DLS studies pointed out a significant increase in the Stokes radius of all proteins upon addition of urea.
We can correct for this bias by comparing these results to the cohesive radius of randomized proteins with similar amino acid frequencies.
Thus, two key strategies have been employed to improve the pharmacokinetics of smaller proteins and peptides, i.e., increasing the size and hydrodynamic radius of the protein or peptide, or increasing the negative charge of the target protein or peptide.
Protein aggregate sizes based on the initial hydrodynamic radius of the protein solution species present were measured using dynamic light scattering, and the relationship between b2 and protein aggregate size was studied.
The Stokes radius of each protein complex was calculated from its elution volume based on the elution profiles of standards of known stokes radii (chymotrypsin A, ovalbumin, aldolase, catalase, ferritin and thyroglobulin) run on the same column.
