Glycerolipid biosynthesis in rat adipose tissue effect of polyamines on triglyceride synthesis

Jamdar, Subhash C.

doi:10.1016/0003-9861(77)90554-9

Cited by 31 publications

(12 citation statements)

References 28 publications

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“…Microsomal (rat adipose tissue and liver) sn-glycerol 3-phosphate acyltransferase and 1,2-diacyl-sn-glycerol acyltransferase were markedly and specifically stimulated by physiological concentrations of spermine independently from Mg21 (Jamdar, 1977(Jamdar, , 1979Bates & Saggerson, 1981); however this action might be due to some extent to the formation of a complex l.etween spermine and the acyl donor, e.g. palmitoyl-CoA, and/or the inhibition of the 1989 hydrolysis ofthis latter compound (Jamdar, 1979).…”

Section: Interaction Of Polyamines With Membrane Componentsmentioning

confidence: 98%

Influence of polyamines on membrane functions

Schuber

1989

Biochemical Journal

420

222

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Section: Interaction Of Polyamines With Membrane Componentsmentioning

confidence: 98%

Influence of polyamines on membrane functions

Schuber

1989

Biochemical Journal

420

222

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“…Antioxidant action of polyamine has been explained by the chelation of metals the prooxidant [3], and further by physical quenching of reactive oxygen species including singlet molecular oxygen and hydroxyl radical [4][5][6][7]. Stimulation of NADPH supply by the activation by spermine of cytosolic NADP-isocitrate dehydrogenase may further contribute to the enhanced biosynthesis of lipids [2,11]. Kinetic analysis of the effect of spermine on the cytosolic enzyme revealed that spermine activated the enzyme ''uncompetitively'': the K m values for isocitrate and NADP and the maximal velocity were increased.…”

Section: Discussionmentioning

confidence: 99%

“…Stimulation of lipid synthesis by polyamine has been explained by the activation of the biosynthetic enzymes such as fatty acid and triacylglycerol [2,11], but may be partly ascribed to the inhibitory and activating effects of spermine on the mitochondrial and cytosolic NADP-isocitrate dehydrogenase. Activation by spermine of cytosolic NADP-isocitrate dehydrogenase can supply NADPH required for the synthesis of lipid.…”

Section: Discussionmentioning

confidence: 99%

Differential effects of polyamine on the cytosolic and mitochondrial NADP‐isocitrate dehydrogenases

et al. 2012

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Two isozymes of NADP-dependent isocitrate dehydrogenases (EC 1.1.1.42) exist in mammalian tissues: mitochondrial (ICD1) and cytosolic (ICD2). Effects of polyamines such as spermine, spermidine, and putrescine on the cytosolic and mitochondrial NADP-isocitrate dehydrogenases were analyzed kinetically. Spermine activated ICD2, the cytosolic NADP-isocitrate dehydrogenase from rat liver with the increase in the maximal velocity and the decrease in the affinity for the substrates isocitrate and NADP. The activating action of spermine can be explained by "the uncompetitive effect," and the dissociation constant of spermine for the enzyme-substrate complex was determined to be 1.68 mM. Spermidine and putrescine showed little or no effect. ICD1, the mitochondrial form of NADP-isocitrate dehydrogenase from rat and porcine heart was inhibited by spermine effectively, and by spermidine and putrescine to a lesser extent. Spermine inhibited the enzyme competitively with respect to NADP, and noncompetitively with respect to isocitrate. K(i) value of the enzyme for spermine was 1.3 mM. These results suggest that activation by spermine of cytosolic NADP-isocitrate dehydrogenase can enhance the antioxidant activity by regeneration of GSH, and further is responsible for the stimulation of lipid biosynthesis in cytosol. Spermine may contribute to NADPH supply by enhancing transhydrogenase (EC1.6.1.2) activity through the spermine-dependent activation of Ca(2+) -incorporation to mitochondria.

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“…Besides their welldocumented function in all processes of growth and cell proliferation by stimulating various steps of protein synthesis (1-61, they are also known to stimulate phospholipid synthesis (7), possibly by activating the phospholipid synthesizing enzymes (8,9). Furthermore, polmines were described to stabilize membranes ( 10, 1 1 ) and to affect several membrane-bound enzymes, such as ATPaes ( 12-141, acetylcholinesterase ( 15,161, and glucose-6phosphatme ( 17).…”

Section: Introductionmentioning

confidence: 99%

Regulation of the F₁-ATPase from mitochondria of Vigna sinensis (L.) Savi cv. Pitiuba by spermine, spermidine, putrescine, Mg²⁺, Na⁺, and K⁺

Peter¹,

Pinheiro²,

Lima³

1981

Can. J. Biochem.

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Mitochondria from Vigna sinensis (L.) Savi cv. Pitiuba contain the polyamines spermine, spermidine, and putrescine. The membrane-bound F1-ATPase from mitochondria of Vigna sinensis is activated by these polyamines at physiological concentrations. The effect of polyamines on the membrane-bound of F1-ATPase is dependent on the concentrations of Na+, K+, MgATP, and Mg2+. Excess Na+ or K+ prevents the activation of the membrane-bound F1-ATPase by spermine and spermidine, but not by putrescine. The most pronounced effects were observed at low MgATP concentrations in the absence of Na+ and K+. At [MgATP] = 0.08 mM, spermine activation of the membrane-bound F1-ATPase was 130%. The membrane-bound F1-ATPase is slightly activated by Mg2+ at lower concentrations and strongly inhibited by Mg2+ at higher concentrations. Activation as well as inhibition is dependent on the substrate MgATP concentration. Although there is competition between Mg2+ and MgATP, the binding sites for these two ligands are different (pseudocompetitive inhibition). The inhibition of the membrane-bound F1-ATPase can be reversed by polyamines. There is evidence that the binding sites for Mg2+ and polyamines are identical. The F1-ATPase detached from the membrane is neither activated by polyamines nor inhibited by Mg2+. Therefore, the binding sites for Mg2+ and polyamines seem to be localized on the membrane.

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Glycerolipid biosynthesis in rat adipose tissue effect of polyamines on triglyceride synthesis

Cited by 31 publications

References 28 publications

Influence of polyamines on membrane functions

Influence of polyamines on membrane functions

Differential effects of polyamine on the cytosolic and mitochondrial NADP‐isocitrate dehydrogenases

Regulation of the F₁-ATPase from mitochondria of Vigna sinensis (L.) Savi cv. Pitiuba by spermine, spermidine, putrescine, Mg²⁺, Na⁺, and K⁺

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Glycerolipid biosynthesis in rat adipose tissue effect of polyamines on triglyceride synthesis

Cited by 31 publications

References 28 publications

Influence of polyamines on membrane functions

Influence of polyamines on membrane functions

Differential effects of polyamine on the cytosolic and mitochondrial NADP‐isocitrate dehydrogenases

Regulation of the F1-ATPase from mitochondria of Vigna sinensis (L.) Savi cv. Pitiuba by spermine, spermidine, putrescine, Mg2+, Na+, and K+

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Regulation of the F₁-ATPase from mitochondria of Vigna sinensis (L.) Savi cv. Pitiuba by spermine, spermidine, putrescine, Mg²⁺, Na⁺, and K⁺