Table 1.
Hydrodynamic radii and related parameters of some crowding agents.
| Macromolecular Crowders | Molecular Mass (kDa) | Hydrodynamic Radius (Å) | Effective Concentration a | Fractional vol. Occupancy Ψ b |
|---|---|---|---|---|
| Poly(ethylene glycol) PEG 2050 | 2 | 3.8 c/11.3 d | ||
| Dextran sulfate 10 e | 10 | <10 | ||
| Bovine pancreatic trypsin inhibitor (BPTI) f | 6.5 | 14.2 | ||
| PEG 4600 d | 4.6 | 17.9 | ||
| Ribonuclease A g | 13.7 | 19.3 | ||
| Lysozyme g | 14.3 | 20.0 | ||
| PEG 6000 d | 6.0 | 20.8 | ||
| PEG 8000 d | 8.0 | 24.5 | ||
| β-Lactoglobulin g | 36.8 | 27.1 | ||
| Hemoglobin g | 64.5 | 33.2 | ||
| Bovine serum albumin (BSA)e | 66.3 | 33.9 | 80 mg/mL | 18% |
| PEG 20000 | 20 | 34.5 h/41.4 d | ||
| Ficoll 70 e | 70 | 40 | 37.5 mg/mL | 17% |
| PEG 35000 d | 35 | 57.0 | ||
| Ficoll 400 e | 400 | 80 | 25 mg/mL | |
| Dextran 670 e | 670 | 210 | ||
| Poly(sodium 4-styrene sulfonate) (PSS) e | 200 | 220 | 50 µg/mL | 0.7% |
| Dextran sulfate 500 e | 500 | 470 | 100 µg/mL | 5.2% |
a The most effective concentrations were determined empirically in terms of accelerated collagen deposition [23]; b Fractional volume occupancy was calculated for some crowding agents based on their hydrodynamic radii and effective concentrations [23]; c Data are taken from [32]; d Data for PEGs of different molecular mass are calculated from their molecular masses using a known scaling law [33]: RH = 0.145 × MW0.571 ± 0.009 Å. Note that PEGs in aqueous solutions are characterized by the ratio ρ = Rg/RH = 1.73, which is greater than the value estimated a Gaussian chain (ρ = 1.5) but is in a good agreement with theoretical predictions for swollen coils (ρ = 1.86) [33]; e Data are taken from [23]; f Calculated based on the empirical formula reported in [34]; g Data are taken from [34]; h Data for PEG 20000 are taken from [35].