Interaction between bile acids and staphylococcal polysaccharide: inhibition of capsule formation in encapsulated mutant strains (taurine+, taurine−) of Staphylococcus aureus

1983 ◽  
Vol 29 (12) ◽  
pp. 1653-1660 ◽  
Author(s):  
Toshichika Ohtomo

In a previous paper, we showed that bile acid derivatives inhibit capsule formation as well as taurine biosynthesis in a taurine+ (Tau+) encapsulated strain of Staphylococcus aureus. In the present study, binding of [14C]cholic acid ([14C]CA) and [14C]taurocholic acid ([14C]TA) to the staphylococcal polysaccharide antigen (SPA) of the capsular fraction was examined. The bile acids were found to bind with SPA via taurine of the Tau+ cells. [14C]CA bound with the SPA fraction of the Tau+ strain within 10–30 min, whereas 60–120 min was required in the binding of [14C]TA. Various bile acids competed with cholic acid binding to Tau+ cells which was shown by the inhibition of binding with cholic acid or taurocholic acid but not with glycholic acid. Binding of bile acid derivatives to a Tau− encapsulated mutant or to capsular material from this mutant was not observed.

2020 ◽  
Author(s):  
Bojana R. Vasiljević ◽  
Edward T. Petri ◽  
Sofija S. Bekić ◽  
Andjelka S. Ćelić ◽  
Ljubica M. Grbović ◽  
...  

Green synthesis of bile acids derivatives and 5β-cholanic acid was achieved under microwave irradiation, and the binding affinity for the ligand binding domain of the glucocorticoid receptor was measured.


1979 ◽  
Vol 25 (2) ◽  
pp. 264-268 ◽  
Author(s):  
O Mäentausta ◽  
O Jänne

Abstract We describe a method for radioimmunoassay of conjugated cholic acid, chenodeoxycholic acid, and deoxycholic acid in serum. In the method, 125I-labeled bile acid conjugates are used as the tracers along with antibodies raised against individual bile acid-bovine serum albumin conjugates. Antibody-bound and free bile acids were separated by polyethylene glycol precipitation (final concentration, 125 g/L). Before radioimmunoassay, 0.1-mL serum samples were precipitated with nine volumes of ethanol, and portions from the supernate were used in the assays. The lowest measurable amounts of the bile acids, expressed as pmol/tube, were: cholic acid conjugates, 2; chenodeoxycholic acid conjugates, 0.5; and deoxycholic acid conjugates. 2. Analytical recovery of bile acids added to bile acid-free serum ranged from 85 to 110%; intra-assay and inter-assay CVs ranged from 3.2 to 5.3% and from 5.3 to 12.2%, respectively. Concentrations (mean +/- SD) of the bile acid conjugates in serum from apparently healthy women and men (in mumol/L) were: cholic acid conjugates, 0.43 +/- 0.17 (n = 126); chenodeoxycholic acid conjugates, 0.47 +/- 0.23 (n = 111); and deoxycholic acid conjugates, 0.33 +/- 0.11 (n = 96). The values for primary bile acids were greatly increased in patients with various hepatobiliary diseases.


2018 ◽  
Vol 84 (10) ◽  
Author(s):  
Heidi Doden ◽  
Lina A. Sallam ◽  
Saravanan Devendran ◽  
Lindsey Ly ◽  
Greta Doden ◽  
...  

ABSTRACTBile acids are important cholesterol-derived nutrient signaling hormones, synthesized in the liver, that act as detergents to solubilize dietary lipids. Bile acid 7α-dehydroxylating gut bacteria generate the toxic bile acids deoxycholic acid and lithocholic acid from host bile acids. The ability of these bacteria to remove the 7-hydroxyl group is partially dependent on 7α-hydroxysteroid dehydrogenase (HSDH) activity, which reduces 7-oxo-bile acids generated by other gut bacteria. 3α-HSDH has an important enzymatic activity in the bile acid 7α-dehydroxylation pathway. 12α-HSDH activity has been reported for the low-activity bile acid 7α-dehydroxylating bacteriumClostridium leptum; however, this activity has not been reported for high-activity bile acid 7α-dehydroxylating bacteria, such asClostridium scindens,Clostridium hylemonae, andClostridium hiranonis. Here, we demonstrate that these strains express bile acid 12α-HSDH. The recombinant enzymes were characterized from each species and shown to preferentially reduce 12-oxolithocholic acid to deoxycholic acid, with low activity against 12-oxochenodeoxycholic acid and reduced activity when bile acids were conjugated to taurine or glycine. Phylogenetic analysis suggests that 12α-HSDH is widespread amongFirmicutes,Actinobacteriain theCoriobacteriaceaefamily, and human gutArchaea.IMPORTANCE12α-HSDH activity has been established in the medically important bile acid 7α-dehydroxylating bacteriaC. scindens,C. hiranonis, andC. hylemonae. Experiments with recombinant 12α-HSDHs from these strains are consistent with culture-based experiments that show a robust preference for 12-oxolithocholic acid over 12-oxochenodeoxycholic acid. Phylogenetic analysis identified novel members of the gut microbiome encoding 12α-HSDH. Future reengineering of 12α-HSDH enzymes to preferentially oxidize cholic acid may provide a means to industrially produce the therapeutic bile acid ursodeoxycholic acid. In addition, a cholic acid-specific 12α-HSDH expressed in the gut may be useful for the reduction in deoxycholic acid concentration, a bile acid implicated in cancers of the gastrointestinal (GI) tract.


1973 ◽  
Vol 45 (3) ◽  
pp. 403-406
Author(s):  
R. A. Smallwood ◽  
P. Jablonski ◽  
J. McK. Watts

1. [14C]Cholesterol was administered intravenously via the umbilical vein to foetal sheep in the latter half of gestation, and the incorporation of radioactive label into foetal bile acids was assessed. 2. After 4 days, 0·5–2% of the radioactive label was found in foetal bile. Seventy to eighty per cent of the radioactive label in foetal bile was present as [14C]taurocholic acid and [14C]taurochenodeoxycholic acid. The remainder was [14C]cholesterol. No radioactive label was found in taurodeoxycholic acid, or in any of the glycine-conjugated bile acids. 3. It is concluded that the foetal sheep liver in the second half of gestation synthesizes taurocholic acid and taurochenodeoxycholic acid. However, the secondary bile acid taurodeoxycholic acid and the glycine-conjugated bile acids, present in foetal bile, have been acquired by placental transfer from the mother.


1990 ◽  
Vol 270 (3) ◽  
pp. 691-695 ◽  
Author(s):  
F Chanussot ◽  
H Lafont ◽  
J Hauton ◽  
B Tuchweber ◽  
I Yousef

The correlation between the secretion of biliary phospholipid (PL) and bile acid suggests a regulatory effect of bile acid on PL secretion. Bile acids may influence PL synthesis and/or the mobilization of a preformed PL pool. The objective of this study was to determine the contribution of these two sources to biliary PL, by using an experimental protocol in which dehydrocholic acid (DHCA) and cholic acid (CA) were infused to manipulate biliary PL secretion. In control rats, there was a steady state in bile flow. PL secretion and the biliary secretion of newly synthesized phosphatidylcholine (PC). The specific radioactivity of PC in bile was significantly higher than in plasma, microsomes and canalicular membranes. DHCA infusion decreased biliary PC secretion rate by 80%, and secretion returned to normal values at the transport maximum of CA. The specific radioactivity of biliary PC was decreased by 30% by DHCA infusion and reached normal values during CA infusion. There were no significant changes in the specific radioactivity of PC in plasma or cellular organelles during infusion of bile acids. These data indicate that: (1) newly synthesized PC contributes a small percentage to biliary PC; thus a preformed pool (microsomal and extrahepatic) is a major source of biliary PL; (2) the contribution of the extrahepatic pool to the biliary PL may be more important than the microsomal pool.


1964 ◽  
Vol 46 (3) ◽  
pp. 405-408 ◽  
Author(s):  
Antti Telkkä ◽  
Toini Lahikainen ◽  
A. N. Kuusisto

ABSTRACT The effect of adrenalectomy on taurocholic acid, the main bile acid of the rat, was studied. The bile was obtained by cannulation from the ductus choledochus. The concentration of taurocholic acid in the bile was determined using thin-layer chromatography. The taurocholic acid concentration in the bile of the adrenalectomized animals was significantly decreased, being about a half that of the control rats. The results are briefly discussed.


1978 ◽  
Vol 171 (2) ◽  
pp. 409-412 ◽  
Author(s):  
G A D Haslewood ◽  
S Ikawa ◽  
L Tökés ◽  
D Wong

1. Bile salts of the green turtle Chelonia mydas (L.) were analysed as completely as possible. 2. They consist of taurine conjugates of 3 alpha, 7 alpha, 12 alpha, 22 xi-tetrahydroxy-5 beta-cholestan-26-oic acid (tetrahydroxysterocholanic acid) and 3 alpha 12 alpha, 22 xi-trihydroxy-5 beta-cholestan-26-oic acid, with minor amounts of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5beta-cholan-24-oic acid (cholic acid), 3alpha, 12 alpha-dihydroxy-5beta-cholan-24-oic acid (deoxycholic acid) and possibly other bile acids. 3. Cholic acid and deoxycholic acid represent the first known examples of bile acids common to chelonians and other animal forms: they may indicate independent evolution in chelonians to C24 bile acids. 4. The discovery of a 7-deoxy C27 bile acid is the first evidence that C27 bile acids or their conjugates have an enterohepatic circulation.


Sign in / Sign up

Export Citation Format

Share Document