Partition behavior of cells and soluble substances in two‐polymer aqueous phase systems

Protein partitioning in two‐phase aqueous polymer systems

“…At high ligand concentrations with tion (39) reduces to equation (38). The Flanagan and Barondes model has generally been applied to protein partitioning studies using the logarithmic form of equation (38): (kd)i = (kd)2, if (cL/kd)i 1 and (cL/kd)* 9 1, equa-A log K,,, = log(KtN/Kp) = N lOg(KL) (40) where KtN is the partition coefficient for the protein when the protein binding sites are saturated. Since, in general, all the quantities in equation (40) (40) are usually nonintegral and sometimes are less than 1.27,45 One possible reason for this is that equation (40) assumes that the ligand association constants in the top and bottom phases are equal.…”

“…(kd)i = (kd)2, if (cL/kd)i 1 and (cL/kd)* 9 1, equa-A log K,,, = log(KtN/Kp) = N lOg(KL) (40) where KtN is the partition coefficient for the protein when the protein binding sites are saturated. Since, in general, all the quantities in equation (40) can be measured except for the number of ligand binding sites N , this equation is most commonly used to obtain estimates for the number of ligand binding sites on the protein.…”

“…Since, in general, all the quantities in equation (40) can be measured except for the number of ligand binding sites N , this equation is most commonly used to obtain estimates for the number of ligand binding sites on the protein. Values of N obtained from equation (40) are usually nonintegral and sometimes are less than 1.27,45 One possible reason for this is that equation (40) assumes that the ligand association constants in the top and bottom phases are equal. However, this is probably not the case .58364 Neither can it necessarily be assumed that the binding constant for each ligand molecule of the proteinligand complex is equal.…”

Theoretical Aspects of Partitioning

“…The first term arises from the fact that the free energy of a charged surface depends on the ionic strength (e.g., Verwey and Overbeek, 1948), which is not the same in both phases if the salts partition unevenly. This conclusion has been criticized by Walter and Anderson (1981), and overlooks a number of important points (see Chapter 3). Measurements of the contact angle as a function of potential and ionic strength by Sharp (1985), and erythrocyte partition as a function of ionic strength by Walter et al (1968b), indicate that the first term is fairly small for erythrocytes, although it may be significant for proteins and polyelectrolytes with high surface charge densities.…”

Centrifugal countercurrent chromatography to elucidate surface differences of adipose tissue‐derived stem cells

“…The cell sample is partitioned in one system, and the two phases are systematically brought into contact with opposite fresh phases. The ability of the CCD to reveal cell heterogeneity is based on the capacity of this technique to detect subtle changes in the cell surface, and it has been applied to different types of cells such as red blood [], lymphocytes [], bone marrow [], and tissue [] cells.…”