Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.3.14 (ATP synthase)
7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cryostat sections incubated for myofibrillar ATPase, SDH, LDH, and alpha-GPDH as well as p-phenylene-diamine stained semithin sections were used to define muscle fibre types in the trunk musculature of the cod (Gadus morhua, L.). Three zones (superficial, intermediate, deep) containing different muscle fibre types are present within both epaxial and hypaxial parts of each myomere subjacent to the lateral line. Atypical relations concerning myofibrillar ATPase activity probably reflects instability of myosin during storage of frozen tissue. The histochemical reaction does not distinguish between myofibrillar and mitochondrial ATPase in cod muscle. Based on ATPase and SDH activities, seven different histochemical profiles of muscle fibres can be identified in trunk musculature of this teleost fish. Attempts to homologize these fibre types with those in cyclostomes or those in higher animals proved futile. The higher number of histochemically defined muscle fibre types in cod might be explained by developmental processes and an admixture of immature fibres throughout life.
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PMID:Histochemical definition of muscle fibre types in the trunk musculature of a teleost fish (cod, Gadus morhua, L.). 14 60

The MgATP binding site of adenylate kinase, located by a combination of NMR and x-ray diffraction, is near three protein segments, five to seven amino acids in length, that are homologous in sequence to segments found in other nucleotide-binding phosphotransferases, such as myosin and F1-ATPase, ras p21 and transducin GTPases, and cAMP-dependent and src protein kinases, suggesting equivalent mechanistic roles of these segments in all of these proteins. Segment 1 is a glycine-rich flexible loop that, on adenylate kinase, may control access to the ATP-binding site by changing its conformation. Segment 2 is an alpha-helix containing two hydrophobic residues that interact with the adenine-ribose moiety of ATP, and a lysine that may bind to the beta- and gamma-phosphates of ATP. Segment 3 is a hydrophobic strand of parallel beta-pleated sheet, terminated by a carboxylate, that flanks the triphosphate binding site. The various reported mutations of ras p21 that convert it to a transforming agent all appear to involve segment 1, and such substitutions may alter the properties of p21 by hindering a conformational change at this segment. In F1-ATPase, the flexible loop may, by its position, control both the accessibility and the ATP/ADP equilibrium constant on the enzyme.
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PMID:ATP-binding site of adenylate kinase: mechanistic implications of its homology with ras-encoded p21, F1-ATPase, and other nucleotide-binding proteins. 286 83

A facile and high-yield synthesis of a new ATP analogue, 2-[(4-azido-2-nitrophenyl)amino]ethyl triphosphate (NANTP), is described. NANTP and ATP are hydrolyzed by skeletal myosin subfragment 1 (SF1) at comparable rates in the presence of Ca2+, Mg2+, or NH4+-EDTA. NANTP is also cleaved but less readily by mitochondrial F1-ATPase and by (Na+ + K+)-ATPase from dog brain and hog kidney. F-Actin markedly activates NANTP cleavage by SF1 in the presence of Mg2+, suggesting that the diphosphate product NANDP is slow to be released from the enzyme. [alpha-32P]NANDP binds to a single site on SF1 (KA = 1 X 10(6) M-1) with an affinity identical with that of ADP. The absorption maximum of NANDP was shifted from 474 to 467 nm upon binding to SF1, suggesting that the purine binding site has a dielectric constant of about 45. NANDP was trapped in nearly stoichiometric amounts at the active site by cross-linking SH1 and SH2 with N,N'-p-phenylenedimaleimide (pPDM) or by chelation with cobalt (III) phenanthroline [Wells, J., & Yount, R. (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 4966]. The trapped [beta-32P]NANDP X SF1 complex, like the comparable ADP X SF1 complex, was stable for days at 0 degree C and could be purified free of extraneous analogue by ammonium sulfate precipitation and gel filtration. Photolysis of the purified complex gave greater than 50% covalent incorporation of the trapped NANDP into the 95-kilodalton (kDa) heavy chain of SF1. Limited trypsinization and analysis by gel electrophoresis showed that greater than 95% of the bound label was associated with the 25-kDa NH2-terminal peptide. Without trapping, NANDP labeling of SF1 was nonspecific and was not prevented by addition of a large excess of ATP. This new approach of trapping photoaffinity analogues by cross-linking agents before photolysis may prove to be of general usefulness in increasing the specificity and extent of labeling of enzymes that undergo substrate-induced conformation changes.
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PMID:2-[(4-Azido-2-nitrophenyl)amino]ethyl triphosphate, a novel chromophoric and photoaffinity analogue of ATP. Synthesis, characterization, and interaction with myosin subfragment 1. 407 91

A statistical method for quantifying the relatedness among proteins was used to perform 2926 paired comparisons of amino-acid composition among 77 contractile and membrane-associated proteins from diverse species and sources. Relatedness of amino-acid compositions correlates with homology of amino-acid sequence. A high degree of relatedness was detected among K(+)-dependent membrane ATPase of Streptococcus faecalis, coupling factors F(1) and CF(1) from mitochondria and chloroplasts, outer fiber protein of cilia, ciliary dynein, tubulin, various actins, and myosin subfragment S-1. Heavy meromyosin and tropomyosin were related to each other but not to the first group of proteins. Differences in the degree of methylation may account for some differences in physiological function. Because of their diverse sources, the high degree of relatedness among these proteins is more compatible with evolution from common ancestral genes than with convergent evolution. Squid axon filarin, molluscan paramyosin, and bacterial flagellins appear to be unrelated either to each other or to any of the other proteins studied. Existence of persistent homologies among so many diverse proteins implies conservation of genetic information during evolution by utilization of codons for preferred amino-acid sequences in various proteins.
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PMID:Relatedness among contractile and membrane proteins: evidence for evolution from common ancestral genes. 427 32

The alpha- and beta-subunits of membrane-bound ATP synthase complex bind ATP and ADP: beta contributes to catalytic sites, and alpha may be involved in regulation of ATP synthase activity. The sequences of beta-subunits are highly conserved in Escherichia coli and bovine mitochondria. Also alpha and beta are weakly homologous to each other throughout most of their amino acid sequences, suggesting that they have common functions in catalysis. Related sequences in both alpha and beta and in other enzymes that bind ATP or ADP in catalysis, notably myosin, phosphofructokinase, and adenylate kinase, help to identify regions contributing to an adenine nucleotide binding fold in both ATP synthase subunits.
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PMID:Distantly related sequences in the alpha- and beta-subunits of ATP synthase, myosin, kinases and other ATP-requiring enzymes and a common nucleotide binding fold. 632 17

High resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), followed by computer-assisted image analysis (PDQUEST) was used to screen atrial and ventricular protein patterns for quantitative and qualitative differences in protein expression. Myocardial proteins from left ventricular (LV) and right atrial (RA) samples from end-stage, failing explanted hearts and from a healthy donor heart (control) were separated by 2-D large gel electrophoresis. Ten RA versus ten LV gels from explanted dilated cardiomyopathic (DCM) hearts were analyzed for quantitative differences in their spot patterns. Of the 197 spots matched to every gel, 40 spots differed significantly in intensity between RA and LV for DCM patients. A larger number of atrial and ventricular gels (20 RA, 20 LV) from DCM patients and from a healthy donor heart (4 RA, 4 LV gels) were analyzed for qualitative differences in protein expression. Three protein spots (SSP 1120: M(r)/pI:20.5 kDa/4.6; SSP 1119: M(r)/pI:20.6 kDa/4.5; SSP 0117:M(r)/pI:20.7/ < 4.5) that are present in all RA gels for DCM patients are absent in all LV gels. Two protein spots (SSP 0112: M(r)/pI:17.2 kDa,/ < 4.4; SSP 0114:M(r)/pI:17.6 kDa/ < 4.4) occur only in all LV gels but not in the RA gels. These five qualitatively differing spots are identical in DCM patients and in the healthy donor heart. Some of the differing spots were internally sequenced and identified as myosin light chain isoforms (myosin light chain 2, atrial; myosin light chain 2, ventricular; myosin light chain 1, atrial) with the Protein Identification Resource (PIR) accession numbers A44451, S03708, A30881, respectively. Additionally, phosphoglycerate mutase (PIR: JQ0750) and ATP synthase alpha chain (PIR: S17193) were identified. Thus, quantitative and qualitative differences between atrial and ventricular protein patterns were identified by 2-D PAGE. A characteristic distribution of myosin light chains between atrial and ventricular human myocardium was found using our approach.
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PMID:Chamber-specific expression of human myocardial proteins detected by two-dimensional gel electrophoresis. 758 73

In the present study, we compared the activities of the cardiac myofibrillar Ca(2+)-activated Mg(2+)-ATPase and the content of cardiac muscle mitochondrial ATPase inhibitor protein (IF1) of several mammalian species covering broad ranges of body mass and heart rate, i.e., from beef cattle to mouse. The cardiac myofibrillar ATPase from each species was assayed over a range of pCa values at pH 7.4. While the cardiac myofibrillar ATPase from all species examined showed essentially identical Ca2+ concentration dependencies with the ATPase in each species activating steeply between pCa 6.5 and 5.5, the maximal ATPase specific activity reached varied considerably from species to species, and this variation was largely independent of the predominant cardiac myosin ATPase isoform present. Thus, while adult beef cattle, pig, dog, and rabbit all contain predominantly the slow cardiac myosin ATPase isoform the cardiac myofibrillar ATPase specific activities of these four species varied over approximately a fourfold range. Moreover, there was a fairly smooth curvilinear relationship between maximum Ca(2+)-activated myofibrillar ATPase activity and median conscious heart rate for the slow cardiac myosin ATPase-possessing species examined. This smooth continuum also extended to include two species possessing the fast cardiac myosin ATPase isoform, rat and mouse. This relationship between myofibrillar ATPase activity and heart rate that appears to be applicable to a broad range of species suggests that the myofibrillar ATPase is specifically modeled or fine-tuned to the kinetic (heart rate) demand of each species and, within slow and fast heart rate ranges, is essentially independent of myosin ATPase isoform per se. Only hearts containing predominantly the slow myosin ATPase isoform contained functional levels of IF1. Finally, while it has been reported that the ratio of myosin Ca(2+)-ATPase to actomyosin Mg(2+)-ATPase activity is a good index of the percent of the fast myosin ATPase in rabbit myofibrillar preparations, we found that this relationship may be applicable to only some species.
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PMID:Isoform-independent heart rate-related variation in cardiac myofibrillar Ca(2+)-activated Mg(2+)-ATPase activity. 896 25

Cells employ a variety of linear motors, such as myosin, kinesin and RNA polymerase, which move along and exert force on a filamentous structure. But only one rotary motor has been investigated in detail, the bacterial flagellum (a complex of about 100 protein molecules). We now show that a single molecule of F1-ATPase acts as a rotary motor, the smallest known, by direct observation of its motion. A central rotor of radius approximately 1 nm, formed by its gamma-subunit, turns in a stator barrel of radius approximately 5nm formed by three alpha- and three beta-subunits. F1-ATPase, together with the membrane-embedded proton-conducting unit F0, forms the H+-ATP synthase that reversibly couples transmembrane proton flow to ATP synthesis/hydrolysis in respiring and photosynthetic cells. It has been suggested that the gamma-subunit of F1-ATPase rotates within the alphabeta-hexamer, a conjecture supported by structural, biochemical and spectroscopic studies. We attached a fluorescent actin filament to the gamma-subunit as a marker, which enabled us to observe this motion directly. In the presence of ATP, the filament rotated for more than 100 revolutions in an anticlockwise direction when viewed from the 'membrane' side. The rotary torque produced reached more than 40 pN nm(-1) under high load.
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PMID:Direct observation of the rotation of F1-ATPase. 906 74

The chemical mechanism by which the F1 moiety of ATP synthase hydrolyzes and synthesizes ATP remains unknown. For this reason, we have carried out studies with orthovanadate (Vi), a phosphate analog which has the potential of "locking" an ATPase, in its transition state by forming a MgADP.Vi complex, and also the potential, in a photochemical reaction resulting in peptide bond cleavage, of identifying an amino acid very near the gamma-phosphate of ATP. Upon incubating purified rat liver F1 with MgADP and Vi for 2 h to promote formation of a MgADP.Vi-F1 complex, the ATPase activity of the enzyme was markedly inhibited in a reversible manner. When the resultant complex was formed in the presence of ultraviolet light inhibition could not be reversed, and SDS-polyacrylamide gel electrophoresis revealed, in addition to the five known subunit bands characteristic of F1 (i.e. alpha, beta, gamma, delta, and epsilon), two new electrophoretic species of 17 and 34 kDa. Western blot and N-terminal sequencing analyses identified both bands as arising from the beta subunit with the site of peptide bond cleavage occurring at alanine 158, a conserved residue within F1-ATPases and the third residue within the nucleotide binding consensus GX4GK(T/S) (P-loop). Quantification of the amount of ADP bound within the MgADP. Vi-F1 complex revealed about 1.0 mol/mol F1, while quantification of the peptide cleavage products revealed that no more than one beta subunit had been cleaved. Consistent with the cleavage reaction involving oxidation of the methyl group of alanine was the finding that [3H] from NaB[3H]4 incorporates into MgADP.Vi-F1 complex following treatment with ultraviolet light. These novel findings provide information about the transition state involved in the hydrolysis of ATP by a single beta subunit within F1-ATPases and implicate alanine 158 as residing very near the gamma-phosphate of ATP during catalysis. When considered with earlier studies on myosin and adenylate kinase, these studies also implicate a special role for the third residue within the GX4GK(T/S) sequence of many other nucleotide-binding proteins.
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PMID:Novel insights into the chemical mechanism of ATP synthase. Evidence that in the transition state the gamma-phosphate of ATP is near the conserved alanine within the P-loop of the beta-subunit. 922 65

The Staphylococcus aureus plasmid gene, vgaB, conferring resistance to streptogramin (SgA) and related compounds (PIIA, virginiamycin M, mikamycin A, synergistin A, Dalfopristin) was cloned and sequenced. This gene potentially encodes a 552-aa protein, VgaB, of 61,327 Da, which exhibits a significant similarity with the ATP-binding domains of numerous proteins. VgaB has two ATP-binding domains containing each of the A and the B motifs described by Walker et al. [Walker, J.E., Saraste, M., Runswick, M.J., Gay, N.J., 1982. Distantly related sequences in the alpha- and beta-subunits of ATP synthase, myosin, kinases and other ATP-requiring enzymes and a common nucleotide binding fold. EMBO J., 1, 945-951], but does not include TM hydrophobic domains. The 155-amino-acid sequence between the two ATP-binding domains of VgaB is richer in Glu than the rest of the protein. The vgaB gene was found in 21 of the 52 SgA(R) and independent wt staphylococci investigated. In each of the 21 staphylococci, vgaB was carried on a plasmid of 50-90 kb also harboring the vatB gene encoding an acetyltransferase inactivating SgA. In all plasmids, vgaB and vatB have the same relative positions.
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PMID:Characterization of a new staphylococcal gene, vgaB, encoding a putative ABC transporter conferring resistance to streptogramin A and related compounds. 942 56


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