scholarly journals Recombinant 2-enoyl-CoA hydratase derived from rat peroxisomal multifunctional enzyme 2: role of the hydratase reaction in bile acid synthesis

1997 ◽  
Vol 328 (2) ◽  
pp. 377-382 ◽  
Author(s):  
Yong-Mei QIN ◽  
M. Antti HAAPALAINEN ◽  
Demara CONRY ◽  
A. Dean CUEBAS ◽  
J. Kalervo HILTUNEN ◽  
...  
Keyword(s):  
Bile Acid ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Hydration Reaction ◽  
Multifunctional Enzymes ◽  
Hydratase Activity ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Liver Peroxisomes ◽  
Enoyl Coa Hydratase

Rat liver peroxisomes contain two multifunctional enzymes: (1) perMFE-1 [2-enoyl-CoA hydratase 1/Δ3,Δ2-enoyl-CoA isomerase/(S)-3-hydroxyacyl-CoA dehydrogenase] and (2) perMFE-2 [2-enoyl-CoA hydratase 2/(R)-3-hydroxyacyl-CoA dehydrogenase]. To investigate the role of the hydratase activity of perMFE-2 in β-oxidation, a truncated version of perMFE-2 was expressed in Escherichia coli as a recombinant protein. The protein catalyses the hydration of straight-chain (2E)-enoyl-CoAs to (3R)-hydroxyacyl-CoAs, but it is devoid of hydratase 1 [(2E)-enoyl-CoA to (3S)-hydroxyacyl-CoA] and (3R)-hydroxyacyl-CoA dehydrogenase activities. The purified enzyme (46 kDa hydratase 2) can be stored as an active enzyme for at least half a year. The recombinant enzyme hydrates (24E)-3α,7α,12α-trihydroxy- 5β-cholest-24-enoyl-CoA to (24R,25R)-3α,7α,12α,24-tetrahydroxy-5β-cholestanoyl-CoA, which has previously been characterized as a physiological intermediate in bile acid synthesis. The stereochemistry of the products indicates that the hydration reaction catalysed by the enzyme proceeds via a syn mechanism. A monofunctional 2-enoyl-CoA hydratase 2 has not been observed as a wild-type protein. The recombinant 46 kDa hydratase 2 described here survives in a purified form under storage, thus being the first protein of this type amenable to application as a tool in metabolic studies.

scholarly journals Identification and characterization of the 2-enoyl-CoA hydratases involved in peroxisomal β-oxidation in rat liver

1997 ◽  
Vol 321 (1) ◽  
pp. 253-259 ◽  
Author(s):  
Martine DIEUAIDE-NOUBHANI ◽  
Dmitry NOVIKOV ◽  
Joël VANDEKERCKHOVE ◽  
Paul P. Van VELDHOVEN ◽  
Guy P. MANNAERTS
Keyword(s):  
Rat Liver ◽  
Hydroxysteroid Dehydrogenase ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Side Chain ◽  
Multifunctional Protein ◽  
Hydratase Activity ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Enoyl Coa Hydratase

In this study we attempted to determine the number of 2-enoyl-CoA hydratases involved in peroxisomal β-oxidation. We therefore separated peroxisomal proteins from rat liver on several chromatographic columns and measured hydratase activities on the eluates with different substrates. The results indicate that rat liver peroxisomes contain two hydratase activities: (1) a hydratase activity associated with multifunctional protein 1 (MFP-1) (2-enoyl-CoA hydratase/Δ3,Δ2-enoyl-CoA isomerase/l-3-hydroxyacyl-CoA dehydrogenase) and (2) a hydratase activity associated with MFP-2 (17β-hydroxysteroid dehydrogenase/d-3-hydroxyacyl-CoA dehydrogenase/2-enoyl-CoA hydratase). MFP-1 forms and dehydrogenates l-3-hydroxyacyl-CoA species, whereas MFP-2 forms and dehydrogenates d-3-hydroxyacyl-CoA species. A portion of MFP-2 is proteolytically cleaved, most probably in the peroxisome, into a 34 kDa 17β-hydroxysteroid dehydrogenase/d-3-hydroxyacyl-CoA dehydrogenase and a 45 kDa d-specific 2-enoyl-CoA hydratase. Finally, the results confirm that MFP-1 is involved in the degradation of straight-chain fatty acids, whereas MFP-2 and its cleavage products seem to be involved in the degradation of the side chain of cholesterol (bile acid synthesis)

The role of α-methylacyl-CoA racemase in bile acid synthesis

2002 ◽  
Vol 363 (3) ◽  
pp. 801-807 ◽  
Author(s):  
Dean A. CUEBAS ◽  
Christopher PHILLIPS ◽  
Werner SCHMITZ ◽  
Ernst CONZELMANN ◽  
Dmitry K. NOVIKOV
Keyword(s):  
Fatty Acids ◽  
Bile Acid ◽  
Alternative Pathway ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Side Chain ◽  
Multifunctional Enzyme ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Dehydrogenation Reactions ◽  
Enoyl Coa Hydratase

According to current views, the second peroxisomal β-oxidation pathway is responsible for the degradation of the side chain of bile acid intermediates. Peroxisomal multifunctional enzyme type 2 [peroxisomal multifunctional 2-enoyl-CoA hydratase/(R)-3-hydroxyacyl-CoA dehydrogenase; MFE-2] catalyses the second (hydration) and third (dehydrogenation) reactions of the pathway. Deficiency of MFE-2 leads to accumulation of very-long-chain fatty acids, 2-methyl-branched fatty acids and C27 bile acid intermediates in plasma, but bile acid synthesis is not blocked completely. In this study we describe an alternative pathway, which allows MFE-2 deficiency to be overcome. The alternative pathway consists of α-methylacyl-CoA racemase and peroxisomal multifunctional enzyme type 1 [peroxisomal multifunctional 2-enoyl-CoA hydratase/(S)-3-hydroxyacyl-CoA dehydrogenase; MFE-1]. (24E)-3α,7α,12α-Trihydroxy-5β-cholest-24-enoyl-CoA, the presumed physiological isomer, is hydrated by MFE-1 with the formation of (24S,25S)-3α,7α,12α,24-tetrahydroxy-5β-cholestanoyl-CoA [(24S,25S)-24-OH-THCA-CoA], which after conversion by a α-methylacyl-CoA racemase into the (24S,25R) isomer can again be dehydrogenated by MFE-1 to 24-keto-3α,7α,12α-trihydroxycholestanoyl-CoA, a physiological intermediate in cholic acid synthesis. The discovery of the alternative pathway of cholesterol side-chain oxidation will improve diagnosis of peroxisomal deficiencies by identification of serum 24-OH-THCA-CoA diastereomer profiles.

Role of the nuclear orphan receptor Rev-erb??; in the regulation of bile acid synthesis

2006 ◽  
Vol 18 (1) ◽  
pp. A44
Author(s):  
T Claudel ◽  
H Duez ◽  
J van der Veen ◽  
C Fontaine ◽  
R Havinga ◽  
...  
Keyword(s):  
Bile Acid ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Orphan Receptor ◽  
Nuclear Orphan Receptor

Role of AMACR (α-methylacyl-CoA racemase) and MFE-1 (peroxisomal multifunctional enzyme-1) in bile acid synthesis in mice

2014 ◽  
Vol 461 (1) ◽  
pp. 125-135 ◽  
Author(s):  
Kaija J. Autio ◽  
Werner Schmitz ◽  
Remya R. Nair ◽  
Eija M. Selkälä ◽  
Raija T. Sormunen ◽  
...  
Keyword(s):  
Bile Acid ◽  
Mouse Models ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Wild Type ◽  
Multifunctional Enzyme

Bile acid analysis of wild-type, Mfe-1−/−, Amacr−/− and Amacr−/−Mfe-1−/− mouse models shows that peroxisomal multifunctional enzyme 1 can participate in bile acid synthesis in both AMACR-dependent and AMACR-independent pathways.

scholarly journals Regulation of bile-acid synthesis. Role of sterol carrier protein2 in the biosynthesis of 7α-hydroxycholesterol

1985 ◽  
Vol 230 (1) ◽  
pp. 19-24 ◽  
Author(s):  
H Seltman ◽  
W Diven ◽  
M Rizk ◽  
B J Noland ◽  
R Chanderbhan ◽  
...  
Keyword(s):  
Bile Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Gas Chromatography Mass Spectrometry ◽  
Rat Liver Microsomes ◽  
Rate Limiting Step ◽  
Rate Limiting

Sterol carrier protein2 (SCP2) is known to stimulate utilization of cholesterol in enzymic reactions in which cholesterol is the substrate. Substantial recent experimental evidence indicates that SCP2: activates enzymic conversion of intermediates between lanosterol and cholesterol; stimulates the microsomal conversion of cholesterol into cholesterol ester in rat liver; and enhances mitochondrial utilization of cholesterol for pregnenolone formation in the adrenals. The conversion of cholesterol into 7 α-hydroxycholesterol is the rate-limiting step in bile-acid synthesis. We therefore investigated the effect of SCP2 on this physiologically critical reaction by using a gas-chromatography-mass-spectrometry procedure that measures the mass of 7 α-hydroxycholesterol formed. The results show that SCP2 enhances 7 α-hydroxycholesterol formation by rat liver microsomes (microsomal fractions), utilizing either endogenous membrane cholesterol, cholesterol supplied exogenously in serum or in the form of cholesterol/phospholipid liposomes. Microsomes immunotitrated with anti-SCP2 antibody exhibited considerably less capacity to synthesize 7 α-hydroxycholesterol, which was restored to control levels on addition of purified SCP2. These data are consistent with the suggestion that SCP2 may be of physiological significance in the overall metabolism of cholesterol.

scholarly journals Evidence that multifunctional protein 2, and not multifunctional protein 1, is involved in the peroxisomal β-oxidation of pristanic acid

1997 ◽  
Vol 325 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Martine DIEUAIDE-NOUBHANI ◽  
Stanny ASSELBERGHS ◽  
Guy P. MANNAERTS ◽  
Paul P. VAN VELDHOVEN
Keyword(s):  
Fatty Acids ◽  
Bile Acid ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Side Chain ◽  
Acid Oxidation ◽  
Synthetic Analogue ◽  
Pristanic Acid ◽  
Multifunctional Protein ◽  
Hydroxyacyl Coa Dehydrogenase

The second (enoyl-CoA hydratase) and third (3-hydroxyacyl-CoA dehydrogenase) steps of peroxisomal β-oxidation are catalysed by two separate multifunctional proteins (MFPs), MFP-1 being involved in the degradation of straight-chain fatty acids and MFP-2 in the β-oxidation of the side chain of cholesterol (bile acid synthesis). In the present study we determined which of the two MFPs is involved in the peroxisomal degradation of pristanic acid by using the synthetic analogue 2-methylpalmitic acid. The four stereoisomers of 3-hydroxy-2-methylpalmitoyl-CoA were separated by gas chromatography after hydrolysis, methylation and derivatization of the hydroxy group with (S)-2-phenylpropionic acid, and the stereoisomers were designated I–IV according to their order of elution from the column. Purified MFP-1 dehydrated stereoisomer IV but dehydrogenated stereoisomer III, so by itself MFP-1 is not capable of converting a branched enoyl-CoA into a 3-ketoacyl-CoA. In contrast, MFP-2 dehydrated and dehydrogenated the same stereoisomer (II), so it is highly probable that MFP-2 is involved in the peroxisomal degradation of branched fatty acids and that stereoisomer II is the physiological intermediate in branched fatty acid oxidation. By analogy with the results obtained with the four stereoisomers of the bile acid intermediate varanoyl-CoA, stereoisomer II can be assigned the 3R-hydroxy, 2R-methyl configuration.

scholarly journals Complex feedback regulation of bile acid synthesis in the hamster: The role of newly synthesized cholesterol

Hepatology ◽  
1999 ◽  
Vol 30 (1) ◽  
pp. 230-237 ◽  
Author(s):  
Jürgen Scheibner ◽  
Michael Fuchs ◽  
Erwin Hörmann ◽  
Eduard F. Stange
Keyword(s):  
Bile Acid ◽  
Feedback Regulation ◽  
Acid Synthesis ◽  
Bile Acid Synthesis

Th-W52:7 Influence of age on bile acid synthesis: Role of hepatic expression of nuclear receptors

2006 ◽  
Vol 7 (3) ◽  
pp. 472
Author(s):  
C. Gabbi ◽  
M. Bertolotti ◽  
C. Anzivino ◽  
D. Macchioni ◽  
M. Crestani ◽  
...  
Keyword(s):  
Bile Acid ◽  
Nuclear Receptors ◽  
Acid Synthesis ◽  
Bile Acid Synthesis ◽  
Hepatic Expression
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