One-step synthesis of radioactive acyl-CoA and acylcarnitines using rat liver mitochondrial outer membrane as enzyme source

Lipids ◽  
1992 ◽  
Vol 27 (5) ◽  
pp. 392-395 ◽  
Author(s):  
A. K. M. Jalaluddin Bhuiyan ◽  
S. V. Pande
Keyword(s):  
Outer Membrane ◽  
Rat Liver ◽  
Mitochondrial Outer Membrane ◽  
One Step ◽  
Enzyme Source

scholarly journals Sensitivity of inhibition of rat liver mitochondrial outer-membrane carnitine palmitoyltransferase by malonyl-CoA to chemical- and temperature-induced changes in membrane fluidity

1990 ◽  
Vol 272 (2) ◽  
pp. 421-425 ◽  
Author(s):  
M P Kolodziej ◽  
V A Zammit
Keyword(s):  
Outer Membrane ◽  
Membrane Fluidity ◽  
Rat Liver ◽  
Isoamyl Alcohol ◽  
Membrane Lipid ◽  
Carnitine Palmitoyltransferase ◽  
Mitochondrial Outer Membrane ◽  
Rat Liver Mitochondria ◽  
Malonyl Coa ◽  
Cpt I

We have tested the possibility that alterations in the fluidity of the outer membrane of rat liver mitochondria could result in changes in the sensitivity of overt carnitine palmitoyltransferase (CPT I) to malonyl-CoA [Zammit (1986) Biochem. Soc. Trans. 14. 676-679]. The sensitivity of CPT I to malonyl-CoA inhibition was measured by using highly purified mitochondrial outer membranes prepared from fed or 48 h-starved rats in the presence and absence of agents that increase membrane fluidity by perturbing membrane lipid order [benzyl alcohol, isoamyl alcohol (3-methylbutan-l-ol) and 2-(2-methoxyethoxy)ethyl-8-(cis-2-n-octylpropyl)octanoate (A2C)]. All these agents resulted in marked decreases in the ability of malonyl-CoA to inhibit CPT I. This effect was accompanied by a modest increase in the absolute activity of CPT I in the absence of malonyl-CoA when the short-chain alcohols were used, but not when A2C was used, suggesting that the effect of increased membrane fluidity to decrease the malonyl-CoA sensitivity of CPT I may occur independently from other actions that may affect more directly the active site of the enzyme. In confirmation of the potential importance of fluidity changes, we showed that a marked increase in sensitivity of CPT I to malonyl-CoA could be produced when assays were performed at lower temperatures than those normally employed. These observations are discussed in the context of the slowness of the changes in CPT I sensitivity to malonyl-CoA inhibition that are induced by physiological perturbations.

Polyunsaturated n-3 and n-6 fatty acids at a low level in the diet alter mitochondrial outer membrane parameters in Wistar rat liver

1995 ◽  
Vol 6 (11) ◽  
pp. 626-634 ◽  
Author(s):  
Pierre Clouet ◽  
Isabelle Niot ◽  
Joseph Gresti ◽  
Jean Demarquoy ◽  
Jacqueline Boichot ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Outer Membrane ◽  
Rat Liver ◽  
Wistar Rat ◽  
Mitochondrial Outer Membrane ◽  
Low Level

scholarly journals Purification of a protein having pore forming activity from the rat liver mitochondrial outer membrane

1982 ◽  
Vol 208 (1) ◽  
pp. 77-82 ◽  
Author(s):  
M Lindén ◽  
P Gellerfors ◽  
B D Nelson
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Rat Liver ◽  
Gradient Centrifugation ◽  
Outer Membrane Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Mitochondrial Outer Membrane ◽  
Rat Liver Mitochondria ◽  
Charge Heterogeneity

A protein with pore-forming activity has been isolated from the outer membrane of rat liver mitochondria. The purification involves sucrose gradient centrifugation, differential centrifugation in the presence of Triton X-100, and DEAE-Sepharose and CM-Sepharose chromatography. The yield of the purified protein was approx. 2% of the total outer membrane proteins. The protein, when inserted into soya bean phospholipid vesicles, increases the [3H]sucrose permeability of the vesicles but had no effect on the permeability of high-molecular-weight [14C]dextran (Mr 70 000). The protein is very active, since as little as 3-4 micrograms of protein per mg of phospholipid is required for the complete release of [3H]sucrose from the vesicles. Sucrose diffusion channels could not be reconstituted with other membrane proteins such as rat liver cytochrome oxidase or cytochrome b5. Purified pore protein revealed a single band of apparent Mr 30000 when resolved by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This polypeptide could be further resolved by isoelectric focusing into a major (pI7.9) and two relatively minor (pI7.6 and 7.2) components. Proteolytic mapping with V8 proteinase from Staphylococcus aureus suggests that these probably represent a single component showing charge heterogeneity. The reason for the charge heterogeneity is not known. The amino acid composition of the protein revealed 47.8% polar amino acids with a relatively high lysine content.

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