Biomedical subjects

B Sumegi

Publications and source records attributed to B Sumegi.

41 records · Page 3Linked to original sources

PubMed1985

Interaction between citrate synthase and thiolase.

Thiolase, a mitochondrial matrix enzyme which produces CoASAc from fatty acids, is shown to interact with citrate synthase, the mitochondrial matrix enzyme responsible for CoASAc utilization. The interaction is demonstrated in three ways: the two enzymes co-precipitate in polyethylene glycol; thiolase causes a change in the fluorescence anisotropy of labeled citrate synthase; and the two enzymes co-elute in gel permeation chromatography. The interactions are shown to be specific by the use of enzymes not metabolically related to citrate synthase.

Acetyl-CoA C-Acyltransferase↗

PubMed1984

Complex I binds several mitochondrial NAD-coupled dehydrogenases.

NADH:ubiquinone reductase (complex I) of the mitochondrial inner membrane respiratory chain binds a number of mitochondrial matrix NAD-linked dehydrogenases. These include pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, mitochondrial malate dehydrogenase, and beta-hydroxyacyl-CoA dehydrogenase. No binding was detected between complex I and cytosolic malate dehydrogenase, glutamate dehydrogenase, NAD-isocitrate dehydrogenase, lipoamide dehydrogenase, citrate synthase, or fumarase. The dehydrogenases that bound to complex I did not bind to a preparation of complex II and III, nor did they bind to liposomes. The binding of pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase complex, and mitochondrial malate dehydrogenase to complex I is a saturable process. Based upon the amount of binding observed in these in vitro studies, there is enough inner membrane present in the mitochondria to bind the dehydrogenases in the matrix space. The possible metabolic significance of these interactions is discussed.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1984

Binding of the enzymes of fatty acid beta-oxidation and some related enzymes to pig heart inner mitochondrial membrane.

The binding of crotonase (enoyl-CoA hydratase), beta-hydroxyacyl-CoA dehydrogenase, beta-ketothiolase, succinyl-CoA transferase, and carnitine acetyltransferase to inner mitochondrial membranes, mitoplasts, intact mitochondria, erythrocyte membranes, and phosphatidylcholine liposomes was studied. Succinyl-CoA transferase does not bind to any of these membranes. Carnitine acetyltransferase, on the other hand, binds to all of these membranes. The enzymes of fatty acid beta-oxidation, thiolase, crotonase, and beta-hydroxyacyl-CoA dehydrogenase bind to inner membrane, but not to liposomes. The binding shows a moderate dependence on ionic strength (2-200 mM) and pH (6.5-8). These data indicate the possibility of an organization of the enzymes of fatty acid beta-oxidation on the inner mitochondrial membrane, but do not support the idea of an organization of the enzymes of ketone body catabolism.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMedDate not supplied

Cloning and sequencing of human oncodevelopmental soluble placental tissue protein 17 (PP17): homology with adipophilin and the mouse adipose differentiation-related protein.

Using a monospecific anti-PP17 antiserum, we detected 4 different molecular-weight PP17 immunoreactive proteins (31,500 kD PP17a, 48, 000 kD PP17b, 60,900 kD PP17c and 74,000 kD PP17d) in different normal adult and fetal human tissues, and in term placenta, by chemiluminescence Western blot analysis. These proteins are overexpressed in cervix carcinoma tissue. Furthermore, increased amounts of PP17b are secreted into the circulation in cervix carcinoma patients; after radical surgery, PP17b serum levels are decreased, and the protein probably has an oncodevelopmental significance. cDNAs were isolated from a human placental cDNA library with the monospecific anti-PP17 antiserum. Sequence analysis of the clones showed that they encode for the 251 residue long PP17a variant, which is identical to the previously isolated and characterized PP17 antigen described in 1983. An alignment search of the protein databank showed that PP17a is homologous to human adipophilin and mouse adipose differentiation-related protein. PP17c turned out to be a dimer of PP17a, while PP17b and PP17d immunoreactive proteins recently detected on Western blots require further investigations.

Adult↗

PubMedDate not supplied

Is placental tissue protein 17b/TIP47 a new factor in cervical cancer genesis?

We identified novel members of the placental tissue protein 17 (PP17) protein family which consists of different-size variants of PP17; cDNAs of PP17a and PP17b variants have also been cloned and sequence analyzed. By Western-blot analysis in cervical carcinoma tissues we found overexpression of PP17b. Compared to healthy controls a mean five-fold increase in the amount of PP17b was also detected in the sera of untreated cervical carcinoma patients, which declined after radical operations. In our recent findings, in sera of inoperable cervical carcinoma patients, we also found elevated PP17b levels which did not change after irradiation. By Northern-blot analyses we confirmed PP17b overexpression in cervical carcinoma tissues and also the alternative splicing of PP17 mRNAs in various normal human tissues. Presently, the amino acid sequence of TIP47--a mannose-6-phosphate receptor cargo selection device--turned out to be identical to that of PP17b. Due to its oncodevelopmental function, PP17b/TIP47 is more than likely to be connected to HSV-2 infection, which is probably one of the main etiopathogenic agents of cervical carcinoma along with the HPV virus, and may open a new trend in the research of pathological processes in human uterine cervical cancer.

Blotting, Northern↗