Relationship between desaturation and chain elongation of palmityl-CoA in rat liver microsomes

Lipids ◽  
1976 ◽  
Vol 11 (3) ◽  
pp. 241-243 ◽  
Author(s):  
M. Nakagawa ◽  
Y. Kawashima ◽  
M. Uchiyama
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Chain Elongation ◽  
Rat Liver Microsomes

scholarly journals Evidence that β-hydroxyacyl-CoA dehydrase purified from rat liver microsomes is of peroxisomal origin

1992 ◽  
Vol 287 (1) ◽  
pp. 91-100 ◽  
Author(s):  
L Cook ◽  
M N Nagi ◽  
S K Suneja ◽  
A R Hand ◽  
D L Cinti
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Competitive Inhibition ◽  
Liver Microsomes ◽  
Carbon Chain ◽  
Enzymic Activity ◽  
Chain Elongation ◽  
Rat Liver Microsomes ◽  
Ph Optimum ◽  
Fatty Acid Chain

The present study provides strong evidence that the previously isolated hepatic microsomal beta-hydroxyacyl-CoA dehydrase (EC 4.2.1.17), believed to be a component of the fatty acid chain-elongation system, is derived, not from the endoplasmic reticulum, but rather from the peroxisomes. The isolated dehydrase was purified over 3000-fold and showed optimal enzymic activity toward beta-hydroxyacyl-CoAs or trans-2-enoyl-CoAs with carbon chain lengths of 8-10. The purified preparation (VDH) displayed a pH optimum at 7.5 with beta-hydroxydecanoyl-CoA, and at 6.0 with beta-hydroxystearoyl-CoA. Competitive-inhibition studies suggested that VDH contained dehydrase isoforms, and SDS/PAGE showed three major bands at 47, 71 and 78 kDa, all of which reacted to antibody raised to the purified preparation. Immunocytochemical studies with anti-rabbit IgG to VDH unequivocally demonstrated gold particles randomly distributed throughout the peroxisomal matrix of liver sections from both untreated and di-(2-ethylhexyl) phthalate-treated rats. No labelling was associated with endoplasmic reticulum or with the microsomal fraction. Substrate-specificity studies and the use of antibodies to VDH and to the peroxisomal trifunctional protein indicated that VDH and the latter are separate enzymes. On the other hand, the VDH possesses biochemical characteristics similar to those of the D-beta-hydroxyacyl-CoA dehydrase recently isolated from rat liver peroxisomes [Li, Smeland & Schulz (1990) J. Biol. Chem. 265, 13629-13634; Hiltunen, Palosaari & Kunau (1989) J. Biol. Chem. 264, 13536-13540]. Neither enzyme utilizes crotonoyl-CoA or cis-2-enoyl-CoA as substrates, but both enzymes convert trans-2-enoyl substrates into the D-isomer only. In addition, the VDH also contained beta-oxoacyl-CoA reductase (beta-hydroxyacyl-CoA dehydrogenase) activity, which co-purified with the dehydrase.

scholarly journals Some factors affecting chain elongation of palmityl-coA in rat liver microsomes.

1976 ◽  
Vol 24 (1) ◽  
pp. 46-51 ◽  
Author(s):  
MITSUO NAKAGAWA ◽  
YOICHI KAWASHIMA ◽  
MITSURU UCHIYAMA
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Chain Elongation ◽  
Rat Liver Microsomes ◽  
Factors Affecting
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