J3- Lactoglobulin

The solubility of a number of proteins in NMA was investigated by Rees and Singer232. Of these insulin and j3-lactoglobulin were found to be soluble to at least one gram per liter while zein is soluble to at least ten grams per liter233). An ORD study of zein in NMA233) led to the conclusion that the helicity (28 °C) is 42%. 

As an example. Fig. 12 shows pH-stat records of the uptake of hydroxyl ions by j3-lactoglobulin in the alkaline region (Nozaki and Bunville, 1959). These are a part of the data from which the two alkaline branches of the titration curve of Fig. 2 were constructed. They also provide, however, a measure of the rate of denaturation of the protein. 

Experimental data on the aggregation of myoglobin and j3-lactoglobulin A previously obtained were used to verify the validity of the VERSE model. The first set... 

The injection of pure j3-lactoglobulin A resulted in three peaks which are, in the order of their elution, a dodecamer, a tetramer, and an octamer. In the calculations, the following stoichiometric equations developed by Grinberg et al. 

Casein is synthesized in the mammary gland and is found nowhere else in nature. Some of the whey proteins (j3-lactoglobulin and a-lactalbumin) are also synthesized in the mammary gland, while others (e.g. bovine serum albumin and the immunoglobulins) are derived from the blood. 

A.5 J3-Lactoglobulin A and B Separation conditions and model parameter used in this book are given below... 

A protein that is antigenically identical to the soluble glycoprotein of the milk fat globule membrane has been identified in whey. By indirect elimination, the major protein components of whey (j3-lactoglobulin, a-lactalbumin, and immunoglobulin G) were shown not to be the anti-(soluble glycoprotein) antibody. 

Chanasattru, W., Jones, O.G., Decker, E.A., McClements, D.J. Impact of cosolvents on formation and properties of biopolymer nanoparticles formed by heat treatment of j3-lactoglobulin-pectin complexes. Food Hydrocolloids 23, 2450-2457 (2009)... 

Similar effects are found in solutions of some, but not all, proteins. Thus horse hemoglobin (Richards, 177) and j3-lactoglobulin (E. J. Cohn, J. D. Ferry, and M. H. Blanchard, unpublished studies, quoted in ref. 39, Chapter 24 Gronwall, 85) become decidedly more soluble in the presence of glycine. The relative solvent effect of glycine on these two proteins, and on cystine, asparagine and glycine is shown in Fig. 7 ... 

Figure 10.18 shows the spectra of native and denatured /J-lactoglobulin A (j3-LG), native myoglobin, and a -casein in DjO solution. In the spectra at pD 1.0 and 7.5 (actually these are pD s 1.4 and 7.9 respectively after the proper corrections are made), the amide I band is like the one observed in the dry film (1632cm with weaker shoulders near 1650 and 1685cm ). In the denatured form (pD 11.5, corrected to 11.9), a single amide I band is displayed at 1643 cm Randomly folded a -casein (Herskovits and Mescanti, 1965) is known to give an almost identical band. 

The production of WPC by UF is today a well-established application in the food and dairy industry. WPC can be further fractionated in j3- and a-lactoglobulin fractions by properly selectingpH,ionicstrength and temperature (Zidney, 1998), or used for the manufacture of caseino-macropeptides with pharmotherapeutic value. 

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