Electrical currents associated with nucleotide transport by the reconstituted mitochondrial ADP/ATP carrier.
AuthorsBrustovetsky N, Becker A, Klingenberg M, Bamberg E
JournalProc Natl Acad Sci U S A
PubMed ID8570612
'The electrophoretic export of ATP against the import of ADP in mitochondria bridges the intra- versus extramitochondrial ATP potential gap. Here we report that the electrical nature of the ADP/ATP exchange by the mitochondrial ADP/ATP carrier (AAC) can be directly studied by measuring the electrical currents via capacitive coupling of ... More
Investigating structural changes induced by nucleotide binding to RecA using difference FTIR.
AuthorsButler BC, Hanchett RH, Rafailov H, MacDonald G
JournalBiophys J
PubMed ID11916875
'Nucleotide binding to RecA results in either the high-DNA affinity form (Adenosine 5''-triphosphate (ATP)-bound) or the more inactive protein conformation associated with a lower affinity for DNA (Adenosine 5''-diphosphate (ADP)-bound). Many of the key structural differences between the RecA-ATP and RecA-ADP bound forms have yet to be elucidated. We have ... More
Real-time imaging reveals that P2Y2 and P2Y12 receptor agonists are not chemoattractants and macrophage chemotaxis to complement C5a is phosphatidylinositol 3-kinase (PI3K)- and p38 mitogen-activated protein kinase (MAPK)-independent.
AuthorsIsfort K, Ebert F, Bornhorst J, Sargin S, Kardakaris R, Pasparakis M, Bähler M, Schwerdtle T, Schwab A, Hanley PJ,
JournalJ Biol Chem
PubMed ID22057273
Adenosine 5'-triphosphate (ATP) has been implicated in the recruitment of professional phagocytes (neutrophils and macrophages) to sites of infection and tissue injury in two distinct ways. First, ATP itself is thought to be a chemotactic ... More
Static and time-resolved structural studies of the Ca2+-ATPase of isolated sarcoplasmic reticulum.
AuthorsBlasie JK, Herbette L, Pierce D, Pascolini D, Scarpa A, Fleischer S
JournalAnn N Y Acad Sci
PubMed ID6220651
X-ray and neutron diffraction studies of oriented multilayers of isolated light sarcoplasmic reticulum (SR) have provided the separate profile structures of the lipid bilayer and the Ca2+-ATPase molecule within the membrane profile to approximately 10 A resolution. These studies utilized biosynthetically deuterated SR phospholipids incorporated isomorphously into the isolated SR ... More
Fluorescence polarization from isomers of tetramethylrhodamine at SH-1 in rabbit psoas muscle fibers.
AuthorsBerger CL, Craik JS, Trentham DR, Corrie JE, Goldman YE
JournalBiophys J
PubMed ID7787111
We have used fluorescence polarization to examine orientational changes of the 5- and 6-isomers of acetamidotetramethylrhodamine (ATR) covalently bound to SH-1 (Cys-707 of the myosin heavy chain) in single, skinned fibers from rabbit psoas muscle after rapid length steps or photolysis of caged nucleotides. Similar results were obtained with both ... More
Photolytic release of MgADP reduces rigor force in smooth muscle.
AuthorsKhromov AS, Somlyo AP, Somlyo AV
JournalBiophys J
PubMed ID11259303
Photolytic release of MgADP (25-300 microM) from caged ADP in permeabilized tonic (rabbit femoral artery-Rfa) and phasic (rabbit bladder-Rbl) smooth muscle in high-tension rigor state, in the absence of Ca(2+), caused an exponential decline (approximately 1.5% in Rfa and approximately 6% in Rbl) of rigor force, with the rate proportional ... More
Fluorescence polarization of skeletal muscle fibers labeled with rhodamine isomers on the myosin heavy chain.
AuthorsBerger CL, Craik JS, Trentham DR, Corrie JE, Goldman YE
JournalBiophys J
PubMed ID8968602
Fluorescence polarization was used to examine orientational changes of Rhodamine probes in single, skinned muscle fibers from rabbit psoas muscle following either photolysis of caged nucleotides or rapid length changes. Fibers were extensively and predominantly labeled at SH1 (Cys-707) of the myosin heavy chain with either the 5- or the ... More
Regulation of force development studied by photolysis of caged ADP in rabbit skinned psoas fibers.
The present study examined the effects of Ca(2+) and strongly bound cross-bridges on tension development induced by changes in the concentration of MgADP. Addition of MgADP to the bath increased isometric tension over a wide range of [Ca(2+)] in skinned fibers from rabbit psoas muscle. Tension-pCa (pCa is -log [Ca(2+)]) ... More
Biochemical and physical parameters of the electrical currents measured with the ADP/ATP carrier by photolysis of caged ADP and ATP.
AuthorsBroustovetsky N, Bamberg E, Gropp T, Klingenberg M
JournalBiochemistry
PubMed ID9374864
The transport by the mitochondrial ADP/ATP carrier (AAC) has been shown in a preliminary communication to produce electrical capacitive currents on photolysis of caged ATP or ADP with reconstituted AAC liposomes attached to black lipid membranes [Brustovetsky, N., Becker, A., Klingenberg, M., and Bamberg, E. (1996) Proc. Natl. Acad. Sci. ... More
ATPase kinetics on activation of rabbit and frog permeabilized isometric muscle fibres: a real time phosphate assay.
AuthorsHe ZH, Chillingworth RK, Brune M, Corrie JE, Trentham DR, Webb MR, Ferenczi MA
JournalJ Physiol
PubMed ID9174999
1. The rate of appearance of inorganic phosphate (Pi) and hence the ATPase activity of rabbit psoas muscle in single permeabilized muscle fibres initially in rigor was measured following laser flash photolysis of the P3-1-(2-nitrophenyl)ethyl ester of ATP (NPE-caged ATP) in the presence and absence of Ca2+. Pi appearance was ... More
Transients in orientation of a fluorescent cross-bridge probe following photolysis of caged nucleotides in skeletal muscle fibres.
AuthorsTanner JW, Thomas DD, Goldman YE
JournalJ Mol Biol
PubMed ID1530978
In muscle fibres labelled with iodoacetamidotetramethylrhodamine at Cys707 of the myosin heavy chain, the probes have been reported to change orientation when the fibre is activated, relaxed or put into rigor. In order to test whether these motions are indications of the cross-bridge power stroke, we monitored tension and linear ... More
Orientation changes in myosin regulatory light chains following photorelease of ATP in skinned muscle fibers.
AuthorsAllen TS, Ling N, Irving M, Goldman YE
JournalBiophys J
PubMed ID8785345
The orientation of the light-chain region of myosin heads in muscle fibers was followed by polarized fluorescence from an extrinsic probe during tension transients elicited by photolysis of caged ATP. Regulatory light chain from chicken gizzard myosin was covalently modified with iodoacetamidotetramethylrhodamine and exchanged into skinned fibers from rabbit psoas ... More
Time-resolved measurements of phosphate release by cycling cross-bridges in portal vein smooth muscle.
AuthorsHe ZH, Ferenczi MA, Brune M, Trentham DR, Webb MR, Somlyo AP, Somlyo AV
JournalBiophys J
PubMed ID9826623
The rate of release of inorganic phosphate (Pi) from cycling cross-bridges in rabbit portal-anterior mesenteric vein smooth muscle was determined by following the fluorescence of the Pi-reporter, MDCC-PBP (Brune, M., J. L. Hunter, S. A. Howell, S. R. Martin, T. L. Hazlett, J. E. T. Corrie, and M. R. Webb. ... More
The role of MgADP in force maintenance by dephosphorylated cross-bridges in smooth muscle: a flash photolysis study.
AuthorsKhromov A, Somlyo AV, Trentham DR, Zimmermann B, Somlyo AP
JournalBiophys J
PubMed ID8599668
The effect of [MgADP] on relaxation from isometric tension, initiated by reducing free [Ca2+] through photolysis of the caged photolabile Ca2+ chelator diazo-2, was determined at 20 degrees C in alpha-toxin permeabilized tonic (rabbit femoral artery, Rf) and phasic (rabbit bladder, Rb) smooth muscle. In Rf, the shape of the ... More