Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 14 patients operated upon for focal cerebral seizures under local anesthesia, cortical electrical activity was compared with the levels of nicotinamide adenine dinucleotide (NADH) observed fluorometrically. NADH levels fell 3 to 15% in response to 5-second intervals of cortical stimulation in 42 of 70 observations. Although a rough correlation was seen between the quantity of current delivered (milliamperes X seconds) and the NADH decrease, this varied from case to case. The presence of cortical afterdischarge often, but not invariably, corresponded to a greater percentage of change in the NADH levels. Averaging the NADH response to sporadic interictal epileptiform discharges failed to demonstrate concomitant NADH reductions. A similar lack of change was seen in four patients in whom low frequency spike foci were induced by topically applied penicillin in cortex destined for excision. Preliminary studies of the topography of spread of NADH change after cortical stimulation indicate that this is usually asymmetrical in human epileptogenic cortex. Under experimental conditions in cats, it seemed possible to differentiate primary from projected epileptiform activity, in that the projected activity had little or no concomitant fall in the NADH level after the electrographic spike. Pathological examination of the excised sites of NADH recording showed, with one exception, fibrous astrocytic transformation of the central cortex layers.
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PMID:Fluorometric monitoring of NADH levels in cerebral cortex: preliminary observations in human epilepsy. 21 33

The peripheral membrane protein fraction released by washing Acholeplasma laidlawii membranes with low-ionic strength buffers contained about 50% of the total membrane-bound ribonuclease and deoxyribonuclease activities. The ATPase, NADH oxidase and p-nitrophenylphosphatase activities remained bound to the membrane even when EDTA was added to the wash fluids, and thus appear to belong to the integral membrane protein group. Serving as a marker for peripheral membrane proteins, the membrane-bound ribonuclease activity was solubilized by bile salts much more effectively than the integral membrane-bound enzymes. On the other hand, the solubilized ribonuclease showed a much lower capacity to reaggregate with other solubilized membrane components to membranous structures. Yet, most of the ribonuclease molecules which were bound to the reaggregated membranes could not be released by low-ionic strength buffer. The reaggregated membranes differed from the native membranes in the absence of particles on their fracture faces obtained by freeze cleaving, and by their much higher labeling by the [125-I]lactoperoxidase iodination system. These results suggest that most of the proteins are exposed on the reaggregated membrane surfaces, with very little, if any, protein embedded in its lipid bilayer core. Enzyme disposition in the A. laidlawii membrane was studied by comparing the activity of isolated membranes with that of membranes of intact cells after treatment with pronase or with an antiserum to membranes. The data indicate the asymmetrical disposition of these activities, the ATPase and NADH oxidase being localized on the inner membrane surface, while the nucleases are exposed on the external membrane surface.
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PMID:Characterization of the mycoplasma membrane proteins. V. Release and localization of membrane-bound enzymes in Acholeplasma laidlawii. 23 52

The cellular transport systems which have been studied up to now have been found to be based on the functioning of specialized proteins anchored asymmetrically in cell membranes. In the present paper we show that a single soluble enzyme inserted at random in a gel slab can drive an uphill transport, provided that asymmetrical boundary conditions force the reversible reaction catalyzed by this enzyme to work forward on one face of the gel slab and backward on the other face. Experimentally, we have used a yeast alcohol dehydrogenase to induce an uphill transport of NADH. It cannot be excluded that comparable structurally symmetrical transport systems also exist in living cells. Such systems would be particularly well suited to preserving cell homeostasis with regard to small solutes.
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PMID:How a soluble enzyme can be forced to work as a transport system: description of an experimental design. 328 86

The kinetic mechanism of SS isozyme of horse liver alcohol dehydrogenase is shown by initial velocity and product inhibition studies to be asymmetrical, being random for ethanol oxidation and compulsory ordered for acetaldehyde reduction. Enzyme isomerization seems to account for the asymmetry in the mechanism. In its interaction with NADH, the SS isozyme resembles classical alcohol dehydrogenase; consequently, the maximal velocity in the direction from ethanol to acetaldehyde appears to be determined by the rate of NADH dissociation. In the direction from acetaldehyde to ethanol, the enzyme isomerization step appears to limit the maximal velocity.
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PMID:Kinetic mechanism of horse liver alcohol dehydrogenase SS. 700 Jan 85

The in vitro incorporation of cytochrome b5 into purified plasma membranes was investigated by biochemical and immunological methods. Plasma membrane preparations incorporated three times less cytochrome b5 than did microsomal preparations; 60% of this cytochrome b5 could not be reduced by the NADH-cytochrome b5 reductase and considered as being bound to the plasma membrane. The morphological observations made after the immunochemical labeling of cytochrome b5 clearly showed a good but asymmetrical distribution of the ferritin labeling: only the inner face of the plasma membrane incorporated cytochrome b5. These results are discussed with respect to theories which concern the subcellular membrane relationships in the cell.
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PMID:The binding of cytochrome b5 to plasma membranes of rat liver: its implication for membrane specificity and biogenesis. 737 3

Energy metabolism and glycolysis of normal human term placental trophoblast in two-sided culture was investigated during differentiation from cytotrophoblast to syncytiotrophoblast, because glycogen metabolism is abnormal in several trophoblast related pregnancy diseases, including pre-eclampsia. After initial recovery of energy and cytoplasmic NADH/NAD+ redox by 24 h of culture, measures of cellular energy state, [ATP], [ADP], [ATP]/[ADP] ratio, ([ATP] + [ADP] + [AMP]), [ATP]/([ATP] + [ADP] + [AMP]) and energy charge remained essentially constant until 72 h, despite periods of increased energy turnover. At 24 h there was a burst of glycogenolysis, and glycolysis indicated by increased lactate production, which coincided with formation of syncytium. Subsequently, there was no resynthesis nor further breakdown of glycogen. At 48 h, oxygen consumption temporarily increased substantially, without increased glycolysis, during functional differentiation of the syncytiotrophoblast. Glucose uptake was constant and largely from the basal (in vivo fetal facing) side. Lactate output into the basal fetal medium was twice as fast as that into the microvillous (maternal) medium, and oxygen uptake was also asymmetrical. The results show that before and after differentiation substantial relatively constant aerobic glycolysis occurs, but that during increased energy demand cytotrophoblast depends on both glycolytic and aerobic energy production whereas syncytiotrophoblast relies on aerobic metabolism.
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PMID:Energy metabolism and glycolysis in human placental trophoblast cells during differentiation. 913 Oct 49

We discovered a new homoplasmic mutation in the mitochondrial cysteine tRNA of a 60-year-old Caucasian male suffering from asymmetrical pure lower motor neuron disease (MND) and temporal lobe epilepsy (TLE). Furthermore, titrations with Amytal, an inhibitor of NADH:CoQ oxidoreductase, revealed mild mitochondrial dysfunction in skeletal muscle tissue, which was described in patients with MND in an earlier report. The mutation was undetectable in 155 Caucasian controls of both sexes, in 40 MND patients and in 13 individuals suffering from TLE. It was, however, detected in a heteroplasmic state in the patient's mother, who did not suffer from a neurological disorder. Since this rare mutation affected a nonconserved base position and was not observed in MND or TLE materials, its relation to disease remains unclear.
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PMID:Mitochondrial tRNA(Cys) mutation A5823G in a patient with motor neuron disease and temporal lobe epilepsy. 1073 84

Hyperactivated sperm motility is usually characterized by high-amplitude flagellar bends and asymmetrical flagellar beating. There is evidence that an inositol 1,4,5-trisphosphate (IP3) receptor-gated Ca2+ store in the base of the flagellum provides Ca2+ to initiate hyperactivation; however, the identity of the store was not known. Ca2+ stores are membrane-bounded organelles, and the only two membrane-bounded organelles found in this region of sperm are the redundant nuclear envelope (RNE) and mitochondria. Transmission electron micrographs revealed two different compartments of RNE, one enriched with nuclear pores and the other containing few pores but extensive membranous structures with enlarged cisternae. Immunolabeling showed that IP3 receptors and calreticulin are located in the region containing enlarged cisternae. In other cell types, mitochondria adjacent to Ca2+ stores are actively involved in modulating Ca2+ signals by taking up Ca2+ released from stores and also may respond by increasing production of NADH and ATP to support increased energy demand. Nevertheless, bull sperm did not show an increase in NADH when Ca2+ was released from intracellular stores by thapsigargin to induce hyperactivation. Consistently, no net increase in ATP production was detected when sperm were hyperactivated, although ATP was hydrolyzed at a greater rate. Furthermore, blocking Ca2+ efflux from mitochondria by CGP-37157, a specific inhibitor of the mitochondrial Na+/Ca2+ exchanger, did not inhibit the development of hyperactivated motility. We concluded that the intracellular Ca2+ store is the part of RNE that contains enlarged cisternae and that Ca2+ is released directly to the axoneme to trigger hyperactivated motility without the active participation of mitochondria.
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PMID:Characterization of the intracellular calcium store at the base of the sperm flagellum that regulates hyperactivated motility. 1260 47

A cDNA clone for cytochrome b(5) was isolated from a cDNA library of an ascidian, Ciona savignyi, by a plaque hybridization method using a digoxigenin-labeled cDNA for the soluble form of human cytochrome b(5). The cDNA is composed of 5'- and 3'-noncoding sequences, and a 396-base pair coding sequence. The 3'-noncoding sequence contains polyadenylation signal sequences. The amino acid sequence of 132 residues deduced from the nucleotide sequence of the cDNA showed 61% identity and 82% similarity to the cytochrome b(5) of another ascidian species, Polyandrocarpa misakiensis, which we previously cloned. The amino-terminal hydrophilic domain of 98 residues contains well-conserved structures around two histidine residues for heme binding. A cDNA expression system was constructed to prepare a putative soluble form of Ciona cytochrome b(5). The recombinant soluble cytochrome b(5) showed an asymmetrical absorption spectrum at 560 nm as is shown by mammalian cytochromes b(5) upon reduction with NADH and NADH-cytochrome b(5) reductase. The recombinant Ciona cytochrome b(5) is reduced by NADH-cytochrome b(5) reductase with an apparent K(m) value of 3.3 microM. This value is similar to that of the cytochrome b(5) of Polyandrocarpa misakiensis. The expression of Ciona cytochrome b(5) mRNA during development was examined by an in situ hybridization method and ubiquitous expression in embryonic tissues was observed. The results indicate that cytochrome b(5) plays important roles in various metabolic processes during development.
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PMID:Structure of a cDNA for Ciona Cytochrome b(5) and the ubiquitous expression of mRNA in embryonic tissues. 1504 25

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is a polyphagous pest originating in China and now widely distributed in Asian countries. This is one of the more serious forestry pests with a broad host range and causes significant economic losses. Molecular comparison has been used to investigate this pest's origin in China, and recent studies have explored the genetic structure among populations in Korea. However, the population structure of this pest in China remains poorly understood. In this study, 13 microsatellite markers and two mitochondrial markers (from nicotinamide adenine dinucleotid (NADH) dehydrogenase subunit 2 (ND2) and NADH dehydrogenase subunit 6 (ND6) regions) were used to reveal the origins and dispersal of L. delicatula based on a genetic analysis of Chinese populations from eight locations. Results show a low to high level of genetic differentiation among populations and significant genetic differentiation between both two clusters and four clusters. The network and phylogenetic analyses for mitochondrial haplotypes and population structure analyses for microsatellite datasets suggest that there is potential gene flow between geographical populations. The populations from Zhejiang and Fujian provinces may come from the other geographical populations in north China. The populations from Beijing, Henan, and Anhui provinces were regarded as the major source of migrants with a high number of migrants leaving (the effective number of migrants (Nem) = 24.40) and the low number of migrants entering (Nem = 2.05) based on the microsatellite dataset, where significant asymmetrical effective migrants to the other populations were detected by non-overlapping 95% confidence intervals.
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PMID:Genetic Diversity and Population Structure of Natural Lycorma delicatula (White) (Hemiptera: Fulgoridea) Populations in China as Revealed by Microsatellite and Mitochondrial Markers. 3154 78


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