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Lactalbumin amino acids

Nitrogen sources include proteins, such as casein, zein, lactalbumin protein hydrolyzates such proteoses, peptones, peptides, and commercially available materials, such as N-Z Amine which is understood to be a casein hydrolyzate also corn steep liquor, soybean meal, gluten, cottonseed meal, fish meal, meat extracts, stick liquor, liver cake, yeast extracts and distillers solubles amino acids, urea, ammonium and nitrate salts. Such inorganic elements as sodium, potassium, calcium and magnesium and chlorides, sulfates, phosphates and combinations of these anions and cations in the form of mineral salts may be advantageously used in the fermentation. [Pg.1062]

Bovine a-lactalbumin is one of the two enzymes in lactose synthetase, and its amino acid sequence shows striking similarities to that of lysozyme.118 A model based on the lysozyme model has been built, and the side-chain interactions found are convincing, showing that the model is essentially correct. The active cleft in the crystal is, however, shorter than that in the model, and is consistent with a mono- or di-saccharide as the substrate. Thus, the lysozyme structure may serve as a model for some enzymes that synthesize and hydrolyze carbohydrates. [Pg.98]

Friedman (21) studied the effect of pH on the amino acid composition of wheat gluten. At pH 10.6 and above (65 C, 3 hours) no cystine was present. LAL increased with pH above 10.6. Lysine decreased over the same range of pH s, while serine and threonine contents dropped sharply at pH 13.9. Friedman concluded that cystine is most sensitive to alkali and that LAL will form most readily if lysine residues are in proximity to the dehydroalanine formed from cystine. Thus, he explained that different steric considerations may explain the different susceptibilities of wheat gluten, casein, and lactalbumin to LAL formation. [Pg.257]

The complete primary structure of the major a-lactalbumin is shown in Figure 3.6 (Brew and Hill 1970 Brew et al. 1970 Vanaman et al. 1970). The B variant consists of 123 amino acid residues with a calculated molecular weight of 14,174, and the A variant differs from it only by having Gin instead of Arg at position 10. [Pg.94]

Brew, K., Castellino, F. J., Vanaman, T. C, and Hill, R. L. 1970. The complete amino-acid sequence of bovine a-lactalbumin. J. Biol. Chem. 245, 4570-4582. [Pg.151]

Schewale, J. G., Sinha, S. K. and Brew, K. 1984. Evolution of a-lactalbumins. The complete amino acid sequence of the a-lactalbumin from a marsupial (Macropus rufogri-seus) and corrections to regions of sequence in bovine and goat a-lactalbumins. J. BioL Chem. 259, 4947-4956. [Pg.165]

About 20% of milk protein is soluble in the aqueous phase of milk. These serum proteins are primarily a mixture of /3-lactoglobulin, a-lactalbumin, bovine serum albumin, and immunoglobulins. Each of these globular proteins has a unique set of characteristics as a result of its amino acid sequence (Swaisgood 1982). As a group, they are more heat sensitive and less calcium sensitive than caseins (Kinsella 1984). Some of these characteristics (Table 11.1) cause large differences in susceptibility to denaturation (de Wit and Klarenbeek 1984). [Pg.586]

Bovine serum albumin is denatured at pH 4 because of repulsion of acidic amino acids (Haurowitz 1963). As with a-lactalbumin, failure to measure the heat of denaturation for bovine serum albumin at pH 3 indicates that it is already unfolded by acid (de Wit and Klarenbeek 1984). It is more stable at pH 7.5 than at pH 6 because of increased activity of thiol groups at high pH. Denaturation is enhanced more by calcium ions than by other anions (Shimada and Matsushita 1981). Fatty acids appear to stabilize bovine serum albumin against heat denaturation (Gumpen et al 1979). [Pg.593]

The application of the primary databases and structural analytical tools will be introduced using a protein from a future experiment. In Experiment 4, you will extract, purify, and characterize a-lactalbumin from bovine milk. To prepare for this activity, here you will learn about the structure of a related protein, a-lactalbumin from humans. We will search databases to find and view its primary and secondary structure and also determine if there are other proteins with a similar amino acid sequence and structure. After completion of these exercises, you will be able to apply these computer tools to proteins of your own choice. [Pg.221]

Another useful structure tool is RasMol (or RasMac). This will allow you to view the detailed structure of a protein and rotate it on coordinates so you can see it from all perspectives. A hyperlink to RasMol is present under the View Structure function just above Chime. You may need to study RasMol instructions provided under Help, or you may use a Ra.s Mol tutorial listed in Table El.2. Another useful protein viewer is tin-Swiss-Protein Pdv Viewer (Table El.2). BLAST is an advanced sequence similarity tool available at NCBI. To access this, go to the NCBI home page (www.ncbi.nlm.nih.gov) and click on BLAST. Then click on Basic BLAST search to obtain a dialogue box into which you may type the amino acid sequence of human a-lactalbumin. This process may be stream lined by downloading the amino acid sequence in FASTA format into a file and transferring the fde into the BLAST dialogue box. BLAST will provide a list of proteins with sequences similar to the one entered. [Pg.222]

Use the techniques outlined in the experimental procedure to explore two enzymes you will study in later experiments. Study the two enzymes malate dehydrogenase (Experiment 10) and tyrosinase (Experiment 5). View structures and look at amino acid sequences as you did for human a-lactalbumin. [Pg.223]

Use the BLAST tool to compare the amino acid sequences for human a-lactalbumin and lysozyme. Repeat the process using BLAST to compare the nucleotide sequences for the genes coding for human a-lactalbumin and lysozyme. [Pg.223]

The specific amino acid side chains on a-lactalbumin responsible for binding to the metal support are not known however, a-lactalbumin is a metalloprotein. Under physiological conditions, it carries one Ca(II) per molecule hence, there are metal binding sites on the protein. Column-bound a-lactalbumin is eluted by a solution of the free ligand imidazole. A flowchart outlining these procedures is shown in Figure E4.3. [Pg.265]

Most proteins have a broad characteristic absorption spectrum centered at about 280 nm. The major absorption is due to the presence of aromatic moieties in the amino acids phenylalanine, tyrosine, and tryptophan. During the a-lactalbumin purification described in this experiment, you will monitor the process by measuring the absorption at 280 nm (A2S0) of column fractions to be sure the experiment is proceeding correctly. You must recognize that you are measuring not the concentration or presence of a-lactalbumin specifically but the total amount of all proteins present. [Pg.266]

Permyakov, S.E., Pershikova, I.V., Khokhlova, T.I., Uversky, V.N., and Permyakov, E.A. 2004. No need to be HAMLET or BAMLET to interact with histones Binding of monomeric alpha-lactalbumin to histones and basic poly-amino acids. Biochemistry 43(19) 5575-5582. [Pg.200]

There are a number of media available which are not based on a detailed investigation of growth requirements, but rather include crude mixtures of nutrients added to promote cell growth. These include lactalbumin hydrolysate (Appendix 1 Table 9) or yeast extract (Appendix 4) to provide an inexpensive source of amino acids or vitamins. Thus Melnick s monkey kidney media A and B (Melnick, 1955) contain lactalbumin hydrolysate and calf serum in Hanks and Earle s BSS, respectively. Chick embryo extract and tryptose phosphate broth (Appendix 1, Tables 11 and 12) are also used occasionally and their use is referred to where appropriate throughout the book. Mitsuhashi and Maramorosch mosquito cell medium contains lactalbumin hydrolysate, yeast extract and foetal calf serum in a specially developed saline (Mitsuhashi and Maramorosch, 1964 Singh, 1967). [Pg.79]

The high levels of amino acids found in haemolymph may be supplied from a 10% lactalbumin hydrolysate supplemented with non-essential amino acids. Few studies have been done on the amino acid requirements of cultured insect cells and, although some media (Grace, 1962) do specify an amino acid mixture, the presence of additives, such as whole egg ultrafiltrate, makes the significance of specific amino acid concentrations doubtful. [Pg.94]

Pro-oxidant conditions are favoured in infant formulae by the presence of iron and of vitamin C and can lead to oxidative damage to tryptophan residues, which here is of particular importance, tryptophan often being the limiting amino acid. Using a-lactalbumin as a model compound, as it is high in tryptophan, Puscasu and Birlouez-Aragon484 studied the loss of fluorescence due to tryptophan (Aex=290/Aem=340 nm) on incubation with lactose, preformed early and advanced MRP (from proteose-peptone, because it is low in tryptophan), H202/Fe2+, or ascorbate/Fe3+. In each case, after 3 h, there was an appreciable loss of tryptophan from the pH 4.6-soluble protein of about 28%. The MRPs, both formed and preformed, exhibited fluorescence at Aex = 350/Aem = 435-440 (major) and Aex = 330/Aem = 420 nm. [Pg.134]

Studies on bovine whey proteins. IV. Amino acid analyses of crystalline / -lactoglobulins and lactalbumin by quantitative paper chromatography. Arch. Biochem. Biophys., 55, 315 (1955). With K. W. Weiss. [Pg.20]


See other pages where Lactalbumin amino acids is mentioned: [Pg.233]    [Pg.176]    [Pg.101]    [Pg.578]    [Pg.112]    [Pg.166]    [Pg.167]    [Pg.436]    [Pg.92]    [Pg.94]    [Pg.221]    [Pg.265]    [Pg.221]    [Pg.265]    [Pg.143]    [Pg.155]    [Pg.93]    [Pg.41]    [Pg.58]    [Pg.315]    [Pg.82]    [Pg.65]    [Pg.59]   
See also in sourсe #XX -- [ Pg.229 ]




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