A study of the heterogeneity and conformation in solution (in 70 % (v/v) aq. ethanol) of gliadin proteins from wheat was undertaken based upon sedimentation velocity in the analytical ultracentrifuge, analysis of the distribution coefficients and ellipsoidal axial ratios assuming quasi-rigid particles, allowing for a range of plausible time-averaged hydration values has been performed. All classical fractions (α, γ, ω slow , ω fast ) show 3 clearly resolved components. Based on the weight-average sedimentation coefficient for each fraction and a weight-averaged molecular weight from sedimentation equilibrium and/or cDNA sequence analysis, all the proteins are extended molecules with axial ratios ranging from ~10-30 with α appearing the most extended and γ the least.

procedure an estimate of (13 ± 1) nm is found for L p and a value of (330 ± 10) g mol

Fitting r = f(c) as opposed to the usual c = f(r) to the inverted form of the sedimentation equilibrium equation for interacting solute (INVEQ algorithm), it is shown by detailed simulation and by experimentation that stable, simultaneous estimates can be retrieved for both virial (2nd BM/3rd CM) and specific interaction (K(a)) terms. In suitable systems estimates for two distinct second virial (BM) and single K(a) terms can equally be defined. Whilst cell loading level is critical, noise level in the interference fringe data is shown to have surprisingly little influence on these outcomes.

No abstract

Solution molar masses and conformations of glycogens from different sources (rabbit, oyster, mussel and bovine) were analysed using sedimentation velocity in the analytical ultracentrifuge, size-exclusion chromatography coupled to multi-angle laser