The following data were obtained for the sedimentation of ca

The following data were obtained for the sedimentation of catalase in 0.10 KCI at 25 degree C, at a speed of 42, 040 rpm: Calculate the sedimentation coefficient. The diffusion coefficient of catalase in the same solvent, at the same temperature is 4.7 times 10^-7 cm^2/sec. The partial specific volume of the protein is 0.73 cc/g. and the density of the 0.1M KCI at 25 degree C is 1.004 g/cc. Calculate the molecular weight of the protein. Both s and D would normally he measured at several protein concentrations and extrapolated to zero concentration before a calculation is made. Connections to standard conditions are calculated as follows: D_20, w = [D_exp] (293.1/T_exp]; S_20, w = S_exp (1 - v rho)_20, w]_exp/(1 - v rho)_exp]_20, w [Y] values listed in Table 5.2.]

Solution

Answer:

The Molecular Weight (MW) analysis is performed for all types of particle size distributions.

In the Cumulants analysis, the average diameter is converted into MW.

The MW analysis requires to enter two sample-dependent parameters, a and b, in order to calculate MW.

The transformation equation for mean molecular weight is as: MW= [a/D]^1/b

where D is the diffusion coefficient

(Suggestions- Please refere to Beckman Manual to learn more about the princeples of centrifugation)

The sedimentation coefficient, s: s = u/w²r

   where u = velocity of the particle

                w = angular velocity of the rotor

                 r = distance from axis of rotation

s is related to the molar weight (MW) of the solute:

s = MW(1-nr)/Nf

   n = partial specific volume of the solute

   r = density of the solvent

   N = Avogadro\'s number

    f = frictional coefficient

Important: VALUES ARE TEMPERATURE DEPENDENT

The sedimentation coefficient, s: s = u/w²r

10^-13 seconds is called a Svedberg, and given the symbol S

S has implied units of s/radian², but the radian² is generally ignored.