Calcium-induced aggregation

Enzymatic coagulation of milk. The enzymatic coagulation of milk involves modification of the casein micelles via limited proteolysis by selected proteinases, called rennets, followed by calcium-induced aggregation of the rennet-altered micelles ... 

ARSL Physical Stability and Calcium Induced Aggregation... 

The functional properties are illustrated by the watCT-qjrotein interactions of soy protein isolate (SPI). SPI, with high solubility, or excessive thermally induced insolubiUzation, or compact calcium-induced aggregates, gives rise to low water-imbibing capacity (WIC) values. The highest WIC results from the balance between intermediate... 

Van Camp, J., Messens, W., Clement, J. and Huyghebaert, A. 1997. Influence of pH and calcium chloride on the high-pressure-induced aggregation of a whey protein concentrate. J. Agric. Food Chem. 45 1600-1607. 

Calcium-induced vesicle aggregation of ARSL may be studied by measuring the turbidity of the vesicle dispersions (as described in Subheading 3.4.1), for physical stability evaluation. ARSL, which are prepared in d.d. H O (or TBS, see Note 11), are diluted with solutions of calcium chloride in order to have final calcium concentrations in the dispersions between 0.43 and 1.8 mM (see Note 12), and at the same time final lipid concentration of 0.065 mM. 

Calcium-induced ARSL aggregation is evaluated by measuring the turbidity of liposome dispersions, as described in Subheading 3.4.1, immediately after mixing with CaCl, as well as after 2, 4, and 24 or 48 h. The initial turbidity of each ARSL dispersions in H O (or buffer) at the beginning of each experiment (time 0) is taken as starting point. 

In calcium induced vesicle aggregation studies, it should be avoided to use phosphate buffers in order to avoid experimental mistakes due to formation and precipitation of calcium phosphates, which will make the vesicle dispersions highly turbid. 

Villagorgin A (55) inhibits acetylcholine induced contraction of guinea-pig ileum and thrombin and calcium ionophore A23187 induced aggregation of human platelets, a calcium-calmodulin mediated event (54). Several of the simple P-carbolines are cytotoxic (Table 1). 1-Acetyl-p-carboline (63) is cytotoxic toward brine shrimp causing 100% mortality in 24 hr (61). 

The classical low angle light scattering technique was useful in characterizing xanthans. Results indicate that xanthan average molecular weight is insensitive to the Ca" " and Mg " ion concentration in typical reservoir brines. Apparently, the calcium ions do not induce aggregation of the molecules in these solvent environments. This observation is consistent with the insensitivity of solution viscosity to brine composition. 

In vitro eotaxin induces aggregation of eosinophils, elevation of intracellular calcium (30,31), induction of respiratory burst, and CDl lb upregulation (50,51). In addition, eotaxin upregulates the expression of ICAM-1 and VCAM-1 on endothelial cells and stimulates the adhesion of eosinophils to endothelial cells (52,53). 

The geometry and surface chemistry of the dendrimer assemblies can be varied through the addition of surfactants. These dendrimer/surfactant aggregates can be tuned to template the formation of the different phases of calcium carbonate [40]. In combination with hexadecyltrimethylammonium bromide (CTAB), small spherical aggregates were formed that induce the formation of vaterite. Over a period of five days, the vaterite was transformed into calcite. The use of the negatively charged surfactant, sodium dodecylsulfonate (SDS), result-... 

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