Bovine serum albumin

About: Bovine serum albumin is a research topic. Over the lifetime, 19981 publications have been published within this topic receiving 571291 citations. The topic is also known as: BSA.

Orosomucoid as one of the serum components contributing to normal capillary permselectivity in rat skeletal muscle

Abstract: The effects of human serum orosomucoid (normal serum concentration 0.7-1.0 g l-1) on capillary permeability were investigated in 12 isolated maximally vasodilated rat hindquarters perfused with bovine serum albumin (50 g l-1) in modified Tyrode. Measurements were made of capillary filtration coefficient (CFC), permeability surface area product (PS) for vitamin B12 and isogravimetric clearance of radiolabelled albumin (Cl alb). The results were compared with those obtained using perfusates without addition of orosomucoid ('albumin group') or perfusates containing horse serum ('serum group'). Clearance of albumin was almost four-fold higher in the albumin than in the serum group, 0.0895 +/- 0.0066 (n = 12) and 0.0252 +/- 0.016 ml min-1 per 100 g (n = 18), respectively, while intermediate Cl alb values were obtained with human orosomucoid in the perfusate (greater than 0.1 g l-1), 0.0436 +/- 0.0034 ml min-1 per 100 g) (n = 8). These changes in Cl alb were not accompanied by any differences in CFC or PS. We conclude that orosomucoid is one of the components in serum (besides albumin) needed for the maintenance of normal permselectivity of the capillary walls of rat skeletal muscle. Alternatively, human orosomucoid is structurally related to other substances exerting this 'serum effect'.

Cholesterol in the growth of organisms of the pleuropneumonia group.

Abstract: SUMMARY: Representative strains of the pleuropneumonia group, originally isolated from animals, grew well on a basal medium containing infusion broth, peptone, yeast extract and agar when this was further enriched with horse serum. The serum could be replaced by an ethereal extract of egg-yolk and fractionation of this suggested that cholesterol might be the active substance promoting growth. Growth was obtained when cholesterol (0.01 mg./ml.) was added to the basal medium, together with starch or bovine albumin. Addition of the acetone-insoluble fraction of egg-yolk with cholesterol gave better results, growth of six of the eight strains tested being equal to that on serum agar; the lecithin and kephalin fractions after purification were less effective. No growth was obtained when starch, bovine albumin or the acetone-insoluble lipid was added to the medium without cholesterol. Cholestanol and stigmasterol were as effective as cholesterol in promoting growth. Oleic acid in high concentrations (> 0.05 mg./ml.) inhibited growth. Both lipid and protein fractions of serum appeared to be concerned in its ability to promote growth.

Transfer of oleic acid between albumin and phospholipid vesicles

Abstract: The net transfer of oleic acid between egg phosphatidylcholine unilamellar vesicles and bovine serum albumin has been monitored by 13C NMR spectroscopy and 90% isotopically substituted [1-13C]oleic acid. The carboxyl chemical shifts of oleic acid bound to albumin were different from those for oleic acid in phospholipid vesicles. Therefore, in mixtures of donor particles (vesicles or albumin with oleic acid) and acceptor particles (fatty acid-free albumin or vesicles), the equilibrium distribution of oleic acid was determined from chemical shift and peak intensity data without separation of donor and acceptor particles. In a system containing equal masses of albumin and phospholipid and a stoichiometry of 4-5 mol of oleic acid per mol of albumin, the oleic acid distribution was pH dependent, with greater than or equal to 80% of the oleic acid associated with albumin at pH 7.4; association was greater than or equal to 90% at pH 8.0. Decreasing the pH below 7.4 markedly decreased the proportion of fatty acid bound to albumin; at pH 5.4, less than or equal to 10% of the oleic acid was bound to albumin and greater than 90% was associated with vesicles. The distribution was reversible with pH and was independent of whether vesicles or albumin acted as a donor. These data suggest that pH may strongly influence the partitioning of fatty acid between cellular membranes and albumin. The 13C NMR method is also advantageous because it provides information about the structural environments of oleic acid bound to albumin or phospholipid, the ionization state of oleic acid in each environment, and the structural integrity of the vesicles. In addition, minimum and maximum limits for the exchange rates of oleic acid among different environments were obtained from the NMR data.