Protein competition between

In general, surface activity behaviour in food colloids is dominated by the proteins and the low-molecular-weight surfactants. The competition between proteins and surfactants determines the composition and properties of adsorbed layers at oil-water and air-water interfaces. In the case of mixtures of proteins with non-surface-active polysaccharides, the resulting surface-activity is usually attributed to the adsorption of protein-polysaccharide complexes. By understanding relationships between the protein-protein, protein-surfactant and protein-polysaccharide interactions and the properties of the resulting adsorbed layers, we can aim to... 

In addition to their role in primary stabilization related to viscosity increase, some hydrocolloids (particularly carrageenan) are traditionally used as secondary stabilizers. Many of the primary stabilizing hydrocolloids, including locust bean gum and carboxy methyl cellulose induce precipitation of the milk proteins in the mix. This phenomenon in ice cream mix is known as wheying-off, and may be due to direct protein-polysaccharide binding and/or protein-polysaccharide incompatibility in the water phase40. The latter phenomenon may be due to decreased solvent quality due to the competition between protein and polysaccharide for solubilisation. 

In conclusion, it may take fairly long times for protein conformations at an interface to become constant, be it after adsorption or after a change in physicochemical conditions. The same holds for protein composition at the interface if competition between proteins can occur. Moreover, the... 

The total protein concentration in bodily fluids can be up to 35% by mass, representing numerous proteins (> 3700) that span a wide range of concentrations. As a result, there is competition between proteins for available NP surface area in a typical biological environment. HSA and fibrinogen may dominate on the particle surface at short exposure times, but these proteins will be subsequently displaced by proteins having a lower abundance but higher affinity at longer exposure times. ... 

Competition between proteins of different types is more complicated. The molecular size may still play an important role but, in view of the discussion in Section 15.5, other variables such as polarity, electrical charge density, and structural stability should be taken into account as well. 

The molecular association process may be viewed (in a similar way as for the protein folding) as a competition between protein-protein and protein-solvent interactions. As the association mode changes, the contacts between atoms of the two proteins are eventually replaced by contacts with solvent molecules and vice versa. A key quantity involved in this process is the balance between the free energy of solvation of each docked geometry and that of the unboimd proteins. 

Dietary copper also appears to be antagonistic to the adverse effects of lead on the hematopoietic system, growth depression, and tissue hypertrophy (Klauder and Peterini 1975). The reduction in uptake of lead and decrease of lead-induced ALAD inhibition upon administration of copper may be achieved through a competition between the two metals for binding to proteins (Underwood 1977). 

Hosoi H, Mizuno H, Miyawaki A, Tahara T (2006) Competition between energy and proton transfer in ultrafast excited-state dynamics of an oligomeric fluorescent protein red Kaede. J PhysChemB 110 22853-22860... 

After synthesis, the mRNA exits the nucleus through a nuclear pore and proceeds to the ribosome for translation into protein. Competing with export and translation is the process of message degradation by cellular ribonucleases. The competition between degradation and translation provides another mechanism to regulate the levels of individual messages. 

Competition between components of a mixture becomes more likely as the hit rate and pool size increase. For a 10% hit rate, competing hits will be found in 26% of mixtures of ten compounds, but only 2.7% in mixtures of three [11]. Unless mixtures are deconvo-luted, competition can lead to false negatives when the competing compounds have different affinities. For screens using protein detection, competition can also produce false positives due to the additive effect of multiple weak binders. Competition can be controlled by limiting the size of mixtures and pooling dissimilar compounds to reduce the likelihood of two compounds binding at the same site. 

The basis for this technique lies in the competition between the test antigen and a labelled antigen for the available binding sites on a fixed amount of antibody. While the binding sites are traditionally associated with an antibody, any source of specific reversible binding sites may be used to create an assay in this format. Examples of such are specific transport proteins such as thyroxine-binding globulin and certain cellular receptors such as opiate or benzodiazepine receptors. Under these circumstances the equilibrium mixture may be represented thus ... 

Cristobal, S., de Gier,J.-W., Nielsen, H., and von Heijne, G. (1999). Competition between sec- and tat-dependent protein translocation in Eschericha coli. EMBOJ. 18, 2982-2990. 

Catez F, Brown DT, MisteU T, Bustin M (2002) Competition between histone HI and HMGN proteins for chromatin binding sites. EMBO Rep 3 760-766... 

It is noteworthy that the CBP/p300 proteins are present in limited quantities thus creating a competition between transcription factors. CBP sequestration or CBP level drop, while inducing specific gene downregulation, could also represent a way to allow specific re-activation of a given gene. HDACi treatment may worsen this problem. 

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