High impact information on LALBA

• The effect on milk production in mice with all endogenous alpha-lactalbumin genes removed and in mice in which the murine genes were then replaced with human homologues is described. alpha-Lactalbumin, and consequently lactose, is essential for normal milk formation, and the human gene is expressed more efficiently than the murine gene [1].
• Titration of the Ca2+-free binding proteins with 45Ca2+ in a flow-dialysis cell, and of Ca2+-free alpha-lactalbumin used as a control, demonstrated the binding stoichiometry and indicated that Ca2+ ions were bound to the mucosal proteins in dilute buffer at pH 7.5 with a Kd of the order of 10 nM [2].
• Evidence that prolactin stimulates alpha-lactalbumin production in mannary tissues from premenarcheal rhesus monkeys [3].
• The amounts of ingested proteins in lambs fed colostrum were much higher than in those fed the milk diet, and their abomasal emptying was faster. alpha-Lactalbumin was highly degraded by abomasal and intestinal proteases, whereas beta-lactoglobulin and in particular the immunoglobulins were less sensitive [4].
• Sequence of the goat alpha-lactalbumin-encoding gene: comparison with the bovine gene and evidence of related sequences in the goat genome [5].

Biological context of LALBA

• Complete nucleotide sequence of ovine alpha-lactalbumin mRNA [6].
• The derived amino acid sequence of ovine pre-alpha-lactalbumin differs from that of its bovine counterpart by 8 amino acid substitutions, all but one originating from single mutations [6].
• The protein and peptide composition [immunoglobulins G1 and (IgG1), beta-lactoglobulin, alpha-lactalbumin, caseins and peptides resulting from casein hydrolysis] of digesta, gastrointestinal tissues, blood and urine were determined in samples taken 0.75 or 4 h after feeding [4].
• Then, levels of beta-lactoglobulin decreased sharply and those of alpha-lactalbumin slowly during the first days of lactation, reaching stable values during the second week postpartum (4 and 1.5 mg/ml) [7].
• The synthesis ratio beta-lactoglobulin/alpha-lactalbumin in explants obtained at 12 and 30 hours postpartum was found to be 3.5 and 1 [7].

Anatomical context of LALBA

• DNA extracted from 25 hamster-sheep hybrid cell lines was subjected, after Southern blotting, to hybridization with CASB, CASK, LALBA, IGF-1 and AMH cDNA probes [8].
• The specificity and specific activity of the antibody were monitored by western blotting and demonstrated the presence of highly specific antibodies to ovine alpha-lactalbumin in the treated egg yolk [9].
• Previous in situ hybridization studies from our laboratory have shown that expression of certain milk protein genes, e.g. alpha-lactalbumin, is very high in most parts of the mammary glands of sheep and cattle, while in other areas containing an abundance of fat globules it is virtually zero (Molenaar et al., 1992) [10].
• Localisation patterns of the transcription factor Stat5b in the udders from pregnant, lactating and involuting ewes were compared with the expression patterns of two major milk protein genes alpha-lactalbumin and alphaS1 casein [11].
• Bovine serum albumin (BSA), either untreated or defatted, was found to be better than polyvinylpyrrolidone, ovalbumin, or alpha-lactalbumin, both at stimulating and maintaining motility levels and at reducing the tendency of the washed spermatozoa to stick to glass [12].

Associations of LALBA with chemical compounds

• The use of caprylic acid for the extraction of the immunoglobulin fraction from egg yolk of chickens immunised with ovine alpha-lactalbumin [9].
• Only one peptide, which was rich in histidine, originated from kappa-CN. beta-Lactoglobulin and alpha-lactalbumin were also identified in the water extract of Feta cheese [13].

Enzymatic interactions of LALBA

• During fermentation and storage of both yoghurt types, alpha-lactalbumin was hydrolyzed to a slightly bigger extent than beta-lactoglobulin [14].

Other interactions of LALBA

• Sheep gene mapping: additional DNA markers included (CASB, CASK, LALBA, IGF-1 and AMH) [8].
• However, alpha-lactalbumin (alpha LA) exhibited an enhancing effect on IL-1 beta production [15].
• Even without added PRL, low concentrations of this milk protein (mean total alpha-lactalbumin production, 1.9 ng/dish) were released into the organ culture medium bathing these relatively immature tissues; most of the epithelial elements were ductal [3].
• Expression patterns of alpha-S1-casein were similar to those of alpha-lactalbumin [16].
• Individual phagocytic cells contained immunoglobulins of the IgA and IgM classes, both K and lambda light chains, secretory component, lactoferrin, and alpha-lactalbumin [17].

Analytical, diagnostic and therapeutic context of LALBA

• Immunoblotting applied to a two dimensional separation permitted the identification of the bands belonging to beta-lg and alpha-lactalbumin fractions [18].
• The cell cultures showed stimulated DNA synthesis in response to mitogens on attached gels and also responded as floating cultures to lactogenic hormones with production of alpha-lactalbumin [19].
• Anion-exchange chromatography and reversed-phase high-performance liquid chromatography (HPLC) showed the presence of two fractions of beta-lactoglobulin but only one of alpha-lactalbumin [20].

References