scholarly journals Characterization of the binding sites for dicarboxylic acids on bovine serum albumin

1991 ◽  
Vol 276 (3) ◽  
pp. 569-575 ◽  
Author(s):  
J H Tonsgard ◽  
S C Meredith
Keyword(s):  
Dicarboxylic Acid ◽  
Binding Site ◽  
Dicarboxylic Acids ◽  
Acid Oxidation ◽  
Affinity Binding ◽  
Reye's Syndrome ◽  
Medium Chain ◽  
High Affinity ◽  
Dodecanedioic Acid ◽  
Long Chain

Dicarboxylic acids are prominent features of several diseases, including Reye's syndrome and inborn errors of mitochondrial and peroxisomal fatty acid oxidation. Moreover, dicarboxylic acids are potentially toxic to cellular processes. Previous studies [Tonsgard, Mendelson & Meredith (1988) J. Clin. Invest. 82, 1567-1573] demonstrated that long-chain dicarboxylic acids have a single high-affinity binding site and between one and three lower-affinity sites on albumin. Medium-chain-length dicarboxylic acids have a single low-affinity site. We further characterized dicarboxylic acid binding to albumin in order to understand the potential effects of drugs and other ligands on dicarboxylic acid binding and toxicity. Progesterone and oleate competitively inhibit octadecanedioic acid binding to the single high-affinity site. Octanoate inhibits binding to the low-affinity sites. Dansylated probes for subdomain 2AB inhibit dodecanedioic acid binding whereas probes for subdomain 3AB do not. In contrast, low concentrations of octadecanedioic acid inhibit the binding of dansylated probes to subdomain 3AB and 2AB. L-Tryptophan, which binds in subdomain 3AB, inhibits hexadecanedioic acid binding but has no effect on dodecanedioic acid. Bilirubin and acetylsalicylic acid, which bind in subdomain 2AB, inhibit the binding of medium-chain and long-chain dicarboxylic acids. Our results suggest that long-chain dicarboxylic acids bind in subdomains 2C, 3AB and 2AB. The single low-affinity binding site for medium-chain dicarboxylic acids is in subdomain 2AB. These studies suggest that dicarboxylic acids are likely to be unbound in disease states and may be potentially toxic.

Intermediary metabolism of Acinetobacter grown on dialkyl ethers

1989 ◽  
Vol 35 (11) ◽  
pp. 1031-1036 ◽  
Author(s):  
Malcolm C. Modrzakowski ◽  
William R. Finnerty
Keyword(s):  
Fatty Acids ◽  
Dicarboxylic Acid ◽  
Chain Length ◽  
Dicarboxylic Acids ◽  
Acid Oxidation ◽  
Methyl Group ◽  
Ether Oxygen ◽  
Dialkyl Ethers ◽  
Long Chain ◽  
Methyl Group Oxidation

The microbial dissimilation of long-chain dialkyl ethers by Acinetobacter sp. H01-N involved a terminal methyl group oxidation of the dialkyl ether substrates, resulting in the formation of ether oxygen containing fatty acids of corresponding chain length. An internal carbon–carbon scission of the dialkyl ethers resulted in the formation of end-product ether fatty acids and corresponding dicarboxylic acids. Cellular carbon and energy were derived from the subsequent metabolism of the dicarboxylic acids. Dicarboxylic acid oxidation, activation, and identification of cellular dicarboxylic acids indicated dibasic acids as intermediates in the metabolism of dialkyl ethers.Key words: dialkyl ethers, dicarboxylic acids, fatty acids, Acinetobacter.

scholarly journals High-affinity binding site for a specific nuclear protein in the human IgM gene

Nature ◽  
1985 ◽  
Vol 315 (6016) ◽  
pp. 254-254
Author(s):  
L. Hennighausen ◽  
U. Siebenlist ◽  
D. Danner ◽  
P. Leder ◽  
D. Rawlins ◽  
...  
Keyword(s):  
Binding Site ◽  
Nuclear Protein ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity ◽  
High Affinity Binding Site ◽  
Specific Nuclear Protein

Regulatory effect of cholecystokinin on subsequent insulin binding to pancreatic acini

1990 ◽  
Vol 258 (4) ◽  
pp. E562-E568
Author(s):  
Y. Okabayashi ◽  
M. Otsuki ◽  
T. Nakamura ◽  
M. Koide ◽  
H. Hasegawa ◽  
...  
Keyword(s):  
Binding Site ◽  
Insulin Binding ◽  
Pancreatic Acinar Cells ◽  
Affinity Binding ◽  
Regulatory Effect ◽  
Pancreatic Acini ◽  
High Affinity Binding ◽  
Receptor Affinity ◽  
High Affinity ◽  
High Affinity Binding Site

We investigated the regulatory effect of cholecystokinin (CCK) on subsequent insulin binding to pancreatic acinar cells. Rat isolated acini were preincubated with various concentrations of CCK octapeptide (CCK-8) at 37 degrees C. Acini were then washed, resuspended in the binding buffer, and incubated with 8.3 pM 125I-labeled insulin for 60 min at 37 degrees C. Pretreatment with CCK-8 caused inhibition of subsequent 125I-insulin binding that was time and concentration dependent. Significant inhibition was observed with 3 pM CCK-8. Computer analysis of the competition-inhibition study with a nonlinear least-squares curve-fitting program revealed that CCK-8 pretreatment of acini reduced the receptor affinity of the high-affinity binding site. This inhibitory action of CCK-8 was not due to the alteration in degradation or internalization of the tracer. When acini were pretreated with 100 pM CCK-8 for 120 min at 4 degrees C, a reduction in the receptor affinity of the high-affinity binding site was also observed. In pancreatic membrane prepared from acini preincubated with 100 pM CCK-8 for 120 min at 37 degrees C, displacement of 125I-insulin (83 pM) by unlabeled insulin (24 degrees C, 1 h) revealed that CCK-8 inhibited 125I-insulin binding by altering the receptor affinity of the high-affinity binding site. In acinar preparations the inhibitory effect of CCK-8 on 125I-insulin binding was abolished when acini were preincubated with CCK-8 and CCK receptor antagonist L 374718 at 37 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Recent Advances in the Pathophysiology of Fatty Acid Oxidation Defects: Secondary Alterations of Bioenergetics and Mitochondrial Calcium Homeostasis Caused by the Accumulating Fatty Acids

2020 ◽  
Vol 11 ◽  
Author(s):  
Alexandre Umpierrez Amaral ◽  
Moacir Wajner
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Calcium Homeostasis ◽  
Acid Oxidation ◽  
Cultured Fibroblasts ◽  
Medium Chain ◽  
Chain Acyl ◽  
Energy Deprivation ◽  
Long Chain

Deficiencies of medium-chain acyl-CoA dehydrogenase, mitochondrial trifunctional protein, isolated long-chain 3-hydroxyacyl-CoA dehydrogenase, and very long-chain acyl-CoA dehydrogenase activities are considered the most frequent fatty acid oxidation defects (FAOD). They are biochemically characterized by the accumulation of medium-chain, long-chain hydroxyl, and long-chain fatty acids and derivatives, respectively, in tissues and biological fluids of the affected patients. Clinical manifestations commonly include hypoglycemia, cardiomyopathy, and recurrent rhabdomyolysis. Although the pathogenesis of these diseases is still poorly understood, energy deprivation secondary to blockage of fatty acid degradation seems to play an important role. However, recent evidence indicates that the predominant fatty acids accumulating in these disorders disrupt mitochondrial functions and are involved in their pathophysiology, possibly explaining the lactic acidosis, mitochondrial morphological alterations, and altered mitochondrial biochemical parameters found in tissues and cultured fibroblasts from some affected patients and also in animal models of these diseases. In this review, we will update the present knowledge on disturbances of mitochondrial bioenergetics, calcium homeostasis, uncoupling of oxidative phosphorylation, and mitochondrial permeability transition induction provoked by the major fatty acids accumulating in prevalent FAOD. It is emphasized that further in vivo studies carried out in tissues from affected patients and from animal genetic models of these disorders are necessary to confirm the present evidence mostly achieved from in vitro experiments.

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