Table 2.
Physical constants and radial diffusion coefficients for cytosolic proteins of rabbit psoas muscle fibers.
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
|---|---|---|---|---|---|---|
| Protein | Mo (kDa) | Rh (nm) | Dw (× 10−7 cm2/s) | D(r,t) (× 10−7 cm2/s) | D (× 10−7 cm2/s) | n |
| Phosphoglucose isomerase | 125.2 | 4.0 | 3.51 | 0.57 | 0.15 | 31 |
| Phosphofructose kinase | 340.3 | 5.7 | 2.48 | 0.20 | 0.08 | 19 |
| Triosephosphate isomerase | 53.3 | 3.0 | 4.69 | 0.99 | 0.23 | 32 |
| Glyceraldehyde-3-phosphate dehydrogenase | 144.7 | 4.2 | 3.34 | 0.50 | 0.25 | 29 |
| Phosphoglycerate mutase | 57.0 | 3.1 | 4.59 | 0.96 | 0.21 | 30 |
| Enolase | 93.9 | 3.7 | 3.87 | 0.70 | 0.16 | 38 |
| Pyruvate kinase | 231.7 | 5.0 | 2.84 | 0.33 | 0.08 | 39 |
| Glycogen phosphorylase | 194.3 | 4.7 | 3.02 | 0.39 | 0.08 | 23 |
| Phosphoglucose mutase | 61.4 | 3.2 | 4.47 | 0.91 | 0.16 | 28 |
| Adenylate kinase | 21.6 | 2.2 | 6.35 | 1.6 | 0.50 | 21 |
| Parvalbumin | 11.9 | 1.8 | 7.75 | 2.1 | 0.68 | 12 |
Column 1 lists the diffusible protein, with glycolytic enzymes in bold type. Column 2 lists the oligomeric molecular weight, Mo (sources listed in Table I of Maughan et al. (3)). Column 3 lists the hydrodynamic radius, Rh, calculated from Rh3 = (3/4π) Vh, where Vh is the hydrodynamic volume of each protein interpolated from the hydrodynamic volume versus molecular weight data of O’Leary (22). See text and Supporting Materials for details. Column 4 lists the estimated value of the diffusion coefficient of the protein in bulk water, Dw (47), calculated from Dw = (kT)/(6πηRh), where k is the Boltzmann constant, T = 280 K, η = 1.45 cP at 7°C, and Rh is from column 3. Column 5 lists values for the Variable D model radial diffusion coefficients D(r,t) at t/a2 = 0.35 and r ∼ a, calculated from an optimized global fit to the experimental data. Column 6 lists values for the Constant D model radial diffusion coefficients (D, constant over the diffusional time course). Column 7 lists the number (n) of fibers sampled. Temperature, 7 ± 1°C; pH 7.3.