Dependence on protein concentration

Aitken and Irvine 17) have recently reported on the stability characteristics of lignin peroxidases. They also have shown that the enzyme was most stable at pH 4.5, although higher pH values were not tested. The stability was dependent on protein concentration and veratryl alcohol had a stabilizing effect. The latter result was contrary to our experience. 

The physical properties of gelatin gels and their dependence on protein concentration, temperature, molecular weight, pH, and added reagents have been thoroughly reviewed by Ferry (1948a). We shall refer only briefly to supplementary work. 

Here Cp is the concentration of protein molecules of charge Zp and Cs is the concentration of counterions of charge Zs (ZpCp + ZSCS = 0) e is the dielectric constant and h the shear viscosity of the solution at concentration Cp h0 is the pure solvent viscosity Dp and D6 are the diffusion coefficients of the protein and counterion at infinite dilution while 7 is the mean ionic activity coefficient. Both 7 and the relative visocity (h0/h) depend on protein concentration... 

Apoferritin was shown to have a sedimentation constant S20W of 17.65 (63). A more recent study (102) has shown that the S value is markedly dependent on protein concentration, and a value of 17.12 S was obtained by extrapolation to zero concentration (Fig. 5). A comparison of the... 

Colloid osmotic pressure A negative pressure that depends on protein concentration (mainly of albumin and globulins) and prevents excess filtration across the capillary wall. 

The sequence includes six cysteine residues, two of which are involved in a disulfide bond, and the N-terminal residue of the protein is an acetylated glycine [52]. Ova has one glycosylation site and two phosphorylation sites [53]. Ova contains 32% p-sheets and 30% a-helix as determined by X-ray crystallography [54, 55]. Some evidences indicate that Ova molecules self-assemble depending on protein concentration and pH. Ova is monomer at concentrations lower than about 0.1% and forms oligomers (dimer, trimer and tetramer) at higher protein concentrations the association behaviour is favoured when pH decreases from a neutral value to the protein p/ [56]. 

Fig. 3 Variation of gyration radius of albumin/ganglioside mixture suspension depending on protein concentration. Open and full marks correspond to albumin/Goia and albumin/Gj,i mixtures, respectively, (O) and ( ), albumin-2-amido-2-deoxy-D-galactose (A) and (A), albumin-N-l-[deoxymaltitol]...

Herein, we discuss interaction between a low charge density polypeptide (gelatin A) and 200 base pair DNA in salt-free aqueous solutions at room temperature (25 °C). The binding profile indicated following dependence on protein concentration DNA condensation (GA < 0.05 % (w/v)), formation and growth of DNA-GA complex (0.05 < GA < 0.1 % (w/v)), and finally formation of overcharged intermolecular soluble complexes followed by complex coacervation [GA > 0.1 % (w/v)]. The material used here is adapted from our earlier work [3, 4]. 

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