Li, Tianwei, Evdokimov, Evgenij, Shen, Rong-Fong, Chao, Chien-Chung, Tekle, Ephrem, Wang, Tao, ...
SUMO, a small ubiquitin-related modifier, is known to covalently attach to a number of nuclear regulatory proteins such as p53, I B, promyelocytic leukemia protein and c-Jun. The sumoylation reaction...
We report potent inhibition of the Mg(II).ATP-dependent protein phosphatase, Fc.M, by the regulatory subunit dimer of type II cAMP-dependent protein kinase, RII2. The protein kinase catalytic subunit...
A mechanism of activation of the ATP.Mg-dependent protein phosphatase (FC.M) has been proposed (Jurgensen, S., Shacter, E., Huang, C. Y., Chock, P. B., Yang, S.-D., Vandenheede, J. R., and Merlevede,...
Shacter, E, Huang, C Y, Chock, P B, ...
The mechanism of activation of the Mg(II) X ATP-dependent phosphatase by the kinase FA has been investigated. The inactive protein phosphatase can be represented as FC X M where FC is the inactive...
Yim, M B, Kang, J H, Yim, H S, Kwak, H S, Chock, P B, Stadtman, E R
Cu,Zn-superoxide dismutase (SOD) is known to be a locus of mutation in familial amyotrophic lateral sclerosis (FALS). Transgenic mice that express a mutant Cu,Zn-SOD, Gly-93--> Ala (G93A), have been...
Kong, S K, Yim, M B, Stadtman, E R, Chock, P B
To determine if nitration of tyrosine residues by peroxynitrite (PN), which can be generated endogenously, can disrupt the phosphorylation of tyrosine residues in proteins involved in cell signaling...
Berlett, B S, Friguet, B, Yim, M B, Chock, P B, Stadtman, E R
Treatment of Escherichia coli glutamine synthetase (GS) with peroxynitrite leads to nitration of some tyrosine residues and conversion of some methionine residues to methionine sulfoxide (MSOX)...
Kwak, H S, Yim, H S, Chock, P B, Yim, M B
We report the detection of endogenous intracellular glutathionyl (GS.) radicals in the intact neuroblastoma cell line NCB-20 under oxidative stress. Spin-trapping and electron paramagnetic resonance...
Phosphorylation of ubiquitin-activating enzyme in cultured cells.
Ubiquitin-activating enzyme, E1, is the first enzyme in the pathway leading to formation of ubiquitin-protein conjugates. E1 exists as two isoforms in human cells which are separable by...
Selective and asymmetric molecular transport across electroporated cell membranes.
Tekle, E, Astumian, R D, Chock, P B
Transport of a divalent cation (Ca2+) and three DNA indicators [ethidium bromide (EB), propidium iodide (PI), and ethidium homodimer (EthD-1)] across electroporated membranes of several mammalian...
Purification and characterization of a ubiquitin carrier protein kinase from HeLa cells.
Protein ubiquitination plays an important role in ATP-dependent protein turnover, and it also may regulate other cellular events. Covalent attachment of ubiquitin to other proteins is catalyzed by...
Substrate channeling in glycolysis: a phantom phenomenon.
Wu, X M, Gutfreund, H, Lakatos, S, Chock, P B
It has been proposed that glycolytic enzymes form multienzyme complexes for direct transfer of metabolites from the producing enzyme to the utilizing one. Reexamination of the supporting evidence,...
Tekle, E, Astumian, R D, Chock, P B
Using the plasmid DNA pSV2-neo (which, when integrated into the cellular genome confers resistance to the antibiotic G418 for selection), we examined and compared the transfection efficiency on NIH...
Association of ubiquitin-activating enzyme with HeLa cell chromosomes during mitosis.
Ubiquitin-activating enzyme (E1) is the first enzyme in the pathway leading to formation of ubiquitin-protein conjugates. Antibodies raised against E1 were affinity purified and used for...
Manganese-dependent disproportionation of hydrogen peroxide in bicarbonate buffer.
Stadtman, E R, Berlett, B S, Chock, P B
At physiological concentrations of HCO3- and CO2, Mn(II) catalyzes disproportionation of H2O2. This catalase-like activity is directly proportional to the concentrations of Mn(II) and H2O2, and it...
Berlett, B S, Chock, P B, Yim, M B, Stadtman, E R
In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per...
Yim, M B, Berlett, B S, Chock, P B, Stadtman, E R
To examine the structural identities of reactive free radicals and the mechanism of the oxidative modification of proteins, we used EPR and spin-trapping methods to investigate the oxidation of amino...
Copper, zinc superoxide dismutase catalyzes hydroxyl radical production from hydrogen peroxide.
Yim, M B, Chock, P B, Stadtman, E R
Cu,Zn superoxide dismutase (Cu,Zn-SOD; EC 1.15.1.1) is known to be inhibited slowly by H2O2. Using EPR and the spin traps 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) and N-tert-butyl-alpha-phenylnitrone...
Srivastava and Bernhard [Srivastava, D. K. & Bernhard, S. A. (1986) Science 234, 1081-1086] have proposed that glycolytic enzymes form multienzyme complexes for the direct transfer of metabolites...
Can free energy be transduced from electric noise?
Astumian, R D, Chock, P B, Tsong, T Y, Chen, Y D, Westerhoff, H V
Recently, it was shown that free energy can be transduced from a regularly oscillating electric field to do chemical or transport work when coupled through an enzyme with appropriate electrical...
Mechanism of the actomyosin ATPase: effect of actin on the ATP hydrolysis step.
Stein, L A, Chock, P B, Eisenberg, E
The Lymn-Taylor model for the actomyosin ATPase suggests that during each cycle of ATP hydrolysis the complex of myosin subfragment 1 (S-1) with actin must dissociate into S-1.ATP plus actin before...
Huang, C Y, Chau, V, Chock, P B, Wang, J H, Sharma, R K
Kinetic studies on the activation of cyclic nucleotide phosphodiesterase (3',5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17) as a function of calmodulin and Ca2+ concentrations have been...
How enzymes can capture and transmit free energy from an oscillating electric field.
Westerhoff, H V, Tsong, T Y, Chock, P B, Chen, Y D, Astumian, R D
Recently, it has been demonstrated that free energy from an alternating electric field can drive the active transport of Rb+ by way of the Na+, K+-ATPase. In the present work, it is shown why many...
Fast reaction techniques were used to study the kinetics of protein fluorescence intensity changes that are associated with the reactions of unadenylylated Escherichia coli glutamine synthetase...
Wright, D E, Noiman, E S, Chock, P B, Chau, V
A novel peptide substrate for adenosine 3',5'-cyclic monophosphate-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37), Leu-Arg-Arg-Trp-Ser-Leu-Gly, was synthesized....
Jurgensen, S R, Chock, P B, Taylor, S, Vandenheede, J R, Merlevede, W
We report potent inhibition of the Mg(II).ATP-dependent protein phosphatase, Fc.M, by the regulatory subunit dimer of type II cAMP-dependent protein kinase, RII2. The protein kinase catalytic subunit...
Rhee, S. G., Park, R., Chock, P. B., Stadtman, E. R.
The interconversion of Escherichia coli glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] between its adenylylated and unadenylylated forms has been used to verify the...
Villafranca, J. J., Rhee, S. G., Chock, P. B.
The paramagnetic effect of Mn(II) on 13C and 31P nuclear magnetic resonance signals from the [2-13C]ATP adenylylated glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming); EC 6.3.1.2] from...
Relaxation Study of Complex Formation between Monovalent Cations and Cyclic Polyethers
Equilibrium quotients for the 1:1 complexes of dibenzo-30-crown-10 with Na+, K+, Rb+, Cs+, NH4+, and T1+ in methanol solution have been determined spectrophotometrically. The observed selectivity...
ε-Adenylylated Glutamine Synthetase: An Internal Fluorescence Probe for Enzyme Conformation
Chock, P. B., Huang, C. Y., Timmons, R. B., Stadtman, E. R.
A fluorescent derivative of ATP, ε-ATP, was used to adenylylate glutamine synthetase (EC 6.3.1.2) from Escherichia coli enzymatically. The ε-adenylylated enzyme exhibits similar catalytic...
A theoretical analysis of monocyclic cascade models shows that the steady-state fraction of covalently modified interconvertible enzyme is a function of 10 different cascade parameters. Because each...
Escherichia coli glutamine synthetase and glycogen phosphorylase are prototypes for models of “closed” and “opened” bicyclic cascade systems. Steady-state functions relating the fractional...
Asymmetric pore distribution and loss of membrane lipid in electroporated DOPC vesicles.
Tekle, E, Astumian, R D, Friauf, W A, Chock, P B
An externally applied electric field across vesicles leads to transient perforation of the membrane. The distribution and lifetime of these pores was examined using...
Tekle, Ephrem, Oubrahim, Hammou, Dzekunov, Sergey M., Kolb, Juergen F., Schoenbach, Karl H., Chock, P. B.
Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses...
Yim, M B, Kang, J H, Yim, H S, Kwak, H S, Chock, P B, Stadtman, E R
Cu,Zn-superoxide dismutase (SOD) is known to be a locus of mutation in familial amyotrophic lateral sclerosis (FALS). Transgenic mice that express a mutant Cu,Zn-SOD, Gly-93--> Ala (G93A), have been...
Kong, S K, Yim, M B, Stadtman, E R, Chock, P B
To determine if nitration of tyrosine residues by peroxynitrite (PN), which can be generated endogenously, can disrupt the phosphorylation of tyrosine residues in proteins involved in cell signaling...
Berlett, B S, Friguet, B, Yim, M B, Chock, P B, Stadtman, E R
Treatment of Escherichia coli glutamine synthetase (GS) with peroxynitrite leads to nitration of some tyrosine residues and conversion of some methionine residues to methionine sulfoxide (MSOX)...
Kwak, H S, Yim, H S, Chock, P B, Yim, M B
We report the detection of endogenous intracellular glutathionyl (GS.) radicals in the intact neuroblastoma cell line NCB-20 under oxidative stress. Spin-trapping and electron paramagnetic resonance...
Phosphorylation of ubiquitin-activating enzyme in cultured cells.
Ubiquitin-activating enzyme, E1, is the first enzyme in the pathway leading to formation of ubiquitin-protein conjugates. E1 exists as two isoforms in human cells which are separable by...
Selective and asymmetric molecular transport across electroporated cell membranes.
Tekle, E, Astumian, R D, Chock, P B
Transport of a divalent cation (Ca2+) and three DNA indicators [ethidium bromide (EB), propidium iodide (PI), and ethidium homodimer (EthD-1)] across electroporated membranes of several mammalian...
Purification and characterization of a ubiquitin carrier protein kinase from HeLa cells.
Protein ubiquitination plays an important role in ATP-dependent protein turnover, and it also may regulate other cellular events. Covalent attachment of ubiquitin to other proteins is catalyzed by...
Substrate channeling in glycolysis: a phantom phenomenon.
Wu, X M, Gutfreund, H, Lakatos, S, Chock, P B
It has been proposed that glycolytic enzymes form multienzyme complexes for direct transfer of metabolites from the producing enzyme to the utilizing one. Reexamination of the supporting evidence,...
Tekle, E, Astumian, R D, Chock, P B
Using the plasmid DNA pSV2-neo (which, when integrated into the cellular genome confers resistance to the antibiotic G418 for selection), we examined and compared the transfection efficiency on NIH...
Association of ubiquitin-activating enzyme with HeLa cell chromosomes during mitosis.
Ubiquitin-activating enzyme (E1) is the first enzyme in the pathway leading to formation of ubiquitin-protein conjugates. Antibodies raised against E1 were affinity purified and used for...
Manganese-dependent disproportionation of hydrogen peroxide in bicarbonate buffer.
Stadtman, E R, Berlett, B S, Chock, P B
At physiological concentrations of HCO3- and CO2, Mn(II) catalyzes disproportionation of H2O2. This catalase-like activity is directly proportional to the concentrations of Mn(II) and H2O2, and it...
Berlett, B S, Chock, P B, Yim, M B, Stadtman, E R
In bicarbonate/CO2 buffer, Mn(II) and Fe(II) catalyze the oxidation of amino acids by H2O2 and the dismutation of H2O2. As the Mn(II)/Fe(II) ratio is increased, the yield of carbonyl compounds per...
Yim, M B, Berlett, B S, Chock, P B, Stadtman, E R
To examine the structural identities of reactive free radicals and the mechanism of the oxidative modification of proteins, we used EPR and spin-trapping methods to investigate the oxidation of amino...
Copper, zinc superoxide dismutase catalyzes hydroxyl radical production from hydrogen peroxide.
Yim, M B, Chock, P B, Stadtman, E R
Cu,Zn superoxide dismutase (Cu,Zn-SOD; EC 1.15.1.1) is known to be inhibited slowly by H2O2. Using EPR and the spin traps 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) and N-tert-butyl-alpha-phenylnitrone...
Srivastava and Bernhard [Srivastava, D. K. & Bernhard, S. A. (1986) Science 234, 1081-1086] have proposed that glycolytic enzymes form multienzyme complexes for the direct transfer of metabolites...
Can free energy be transduced from electric noise?
Astumian, R D, Chock, P B, Tsong, T Y, Chen, Y D, Westerhoff, H V
Recently, it was shown that free energy can be transduced from a regularly oscillating electric field to do chemical or transport work when coupled through an enzyme with appropriate electrical...
Mechanism of the actomyosin ATPase: effect of actin on the ATP hydrolysis step.
Stein, L A, Chock, P B, Eisenberg, E
The Lymn-Taylor model for the actomyosin ATPase suggests that during each cycle of ATP hydrolysis the complex of myosin subfragment 1 (S-1) with actin must dissociate into S-1.ATP plus actin before...
Huang, C Y, Chau, V, Chock, P B, Wang, J H, Sharma, R K
Kinetic studies on the activation of cyclic nucleotide phosphodiesterase (3',5'-cyclic-nucleotide 5'-nucleotidohydrolase, EC 3.1.4.17) as a function of calmodulin and Ca2+ concentrations have been...
How enzymes can capture and transmit free energy from an oscillating electric field.
Westerhoff, H V, Tsong, T Y, Chock, P B, Chen, Y D, Astumian, R D
Recently, it has been demonstrated that free energy from an alternating electric field can drive the active transport of Rb+ by way of the Na+, K+-ATPase. In the present work, it is shown why many...
Fast reaction techniques were used to study the kinetics of protein fluorescence intensity changes that are associated with the reactions of unadenylylated Escherichia coli glutamine synthetase...
Wright, D E, Noiman, E S, Chock, P B, Chau, V
A novel peptide substrate for adenosine 3',5'-cyclic monophosphate-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37), Leu-Arg-Arg-Trp-Ser-Leu-Gly, was synthesized....
Jurgensen, S R, Chock, P B, Taylor, S, Vandenheede, J R, Merlevede, W
We report potent inhibition of the Mg(II).ATP-dependent protein phosphatase, Fc.M, by the regulatory subunit dimer of type II cAMP-dependent protein kinase, RII2. The protein kinase catalytic subunit...
Rhee, S. G., Park, R., Chock, P. B., Stadtman, E. R.
The interconversion of Escherichia coli glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] between its adenylylated and unadenylylated forms has been used to verify the...
Villafranca, J. J., Rhee, S. G., Chock, P. B.
The paramagnetic effect of Mn(II) on 13C and 31P nuclear magnetic resonance signals from the [2-13C]ATP adenylylated glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming); EC 6.3.1.2] from...
Relaxation Study of Complex Formation between Monovalent Cations and Cyclic Polyethers
Equilibrium quotients for the 1:1 complexes of dibenzo-30-crown-10 with Na+, K+, Rb+, Cs+, NH4+, and T1+ in methanol solution have been determined spectrophotometrically. The observed selectivity...
ε-Adenylylated Glutamine Synthetase: An Internal Fluorescence Probe for Enzyme Conformation
Chock, P. B., Huang, C. Y., Timmons, R. B., Stadtman, E. R.
A fluorescent derivative of ATP, ε-ATP, was used to adenylylate glutamine synthetase (EC 6.3.1.2) from Escherichia coli enzymatically. The ε-adenylylated enzyme exhibits similar catalytic...
A theoretical analysis of monocyclic cascade models shows that the steady-state fraction of covalently modified interconvertible enzyme is a function of 10 different cascade parameters. Because each...
Escherichia coli glutamine synthetase and glycogen phosphorylase are prototypes for models of “closed” and “opened” bicyclic cascade systems. Steady-state functions relating the fractional...
Asymmetric pore distribution and loss of membrane lipid in electroporated DOPC vesicles.
Tekle, E, Astumian, R D, Friauf, W A, Chock, P B
An externally applied electric field across vesicles leads to transient perforation of the membrane. The distribution and lifetime of these pores was examined using...
Tekle, Ephrem, Oubrahim, Hammou, Dzekunov, Sergey M., Kolb, Juergen F., Schoenbach, Karl H., Chock, P. B.
Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses...