The role of the nicotinamide moiety of NAd+ for negative cooperativity in glyceraldehyde-3-phosphate dehydrogenase as studied by spin-labeled cofactors

Two derivatives of NAD+ spin-labeled at N6 or C-8 of the adenine ring have been shown previously to be active coenzymes of glyceraldehyde-3-phosphate dehydrogenase (D-glyceraldehyde-3-phosphate: NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12). When more than two equivalents of either spin-labeled NAD+ are bound to the tetrameric enzyme, spin-spin interaction is observed in the ESR spectra (Deparade, M.P., Glöggler, K. and Trommer, W.E. (1981) Biochim. Biophys, Acta 659, 422-433). After reduction of enzyme-bound NAD+ spin-labeled at C-8 to the corresponding NADH derivative, the additional peaks due to this spin-spin interaction disappear, which implies that the distance between the two radicals increases. It is proposed that the coenzyme slide further towards the active site upon reduction. ADPR spin-labeled at C-8 binds non-cooperatively, exhibiting a dissociation constant of Kd = 33 microM. Even with 3.5 equivalents bound to the enzyme, spin-spin interaction is not observed. AMP spin-labeled at C-8 combines with two sites per monomer, or a total of eight per tetramer. The respective dissociation constants are Kd1 = 30 microM and Kd2 - 2.3 mM. Phosphate competes with AMP bound to the weak site. Spin-spin interaction is not observed. ATP spin-labeled at C-8 is bound about 10-fold tighter than the corresponding AMP derivative. Four equivalents of ATP are bound per tetramer, but it exhibits no spin-spin interactions. It is concluded that the structure of the pyridine moiety of the coenzymes plays a role in orienting the adenine ring and, thus, affects the cooperativity. The N6 derivative of NAD+ also shows spin-spin interaction; however, only data for the C-8 derivatives are shown in detail.

Etiology of viral hepatitis in American soldiers

To define better which types of hepatitis are prevalent among American soldiers, the authors studied 413 separate episodes of acute viral hepatitis among 412 soldiers admitted to US Army hospitals during 1978-1979. Most soldiers (68.8%) had acute hepatitis B (estimated annual hospitalization rate: 5.41/1000 soldiers in West Germany, 2.51/1000 in South Korea, less than 1/1000 in the United States). Subtype ayw was predominant in Germany, whereas adr was predominant in South Korea. Hepatitis B was more often associated with contact history or parenteral use of drugs in West Germany than in South Korea (p less than 0.001). Non-A, non-B hepatitis accounted for 27% of cases in West Germany (2.16/1000), but only 3% in South Korea (0.11/1000); hepatitis A only 15% in South Korea (0.48/1000) and 1% in West Germany (0.08/1000). These findings indicate that hepatitis B is the most prevalent form of viral hepatitis among US soldiers worldwide but also suggest substantial differences in the epidemiology of this infection in South Korea and West Germany. Such data will be useful in developing hepatitis B immunization policy within the military.

Equilibrium binding of spin-labeled fatty acids to bovine serum albumin: suitability as surrogate ligands for natural fatty acids

Electron paramagnetic resonance (EPR) and saturation transfer EPR (ST-EPR) spectroscopies were used to characterize the binding of spin-labeled fatty acid (SLFA) to bovine serum albumin (BSA). Association constants of three stearic acid derivatives labeled with a nitroxyl radical at C-5, C-12, or C-16 were estimated by EPR spectroscopy as the ratio of SLFA to BSA was increased from about 0 to 9. The values were compared to those for unmodified stearate. With all three SLFA, it was apparent that the nitroxyl residue modified the binding pattern. For SLFA:BSA ratios up to 1, which probably involves the site(s) on BSA most specific for long-chain FA, the C-16 derivative bound with an affinity similar to that of the natural FA. At higher ratios, the association constants for this SLFA were lower than those for stearate. The C-12 and C-5 derivatives showed only low-affinity binding relative to stearate. The spectral parameter, W, was constant for SLFA:BSA ratios between 0 and 1 in the case of C-16 compound, indicating physical homogeneity of the high-affinity binding site. At higher ratios, the spectra changed progressively, indicating inhomogeneity of the lower affinity binding sites although parallel changes in association constants were not observed. Changes in W due to Heisenberg spin exchange were ruled out. By examining the mobility profile of the bound SLFA by both EPR and ST-EPR techniques, it was shown that the nitroxyl group was maximally immobilized when attached near the center of the carbon chain of the bound SLFA.

Effect of interferogram smearing on atmospheric limb sounding by Fourier transform spectroscopy

A method is presented for analyzing an absorption spectrum obtained from the interferogram measured by an interferometer operated in the solar occultation mode. In this mode the complete interferogram is smeared with various components of individual interferograms generated by rays passing through different tangent altitudes. It is shown that the effective tangent altitude of the spectrum is the altitude at which the center fringe of the interferogram is recorded and that the other components of the interferogram only define the instrument line shape. The interferogram smearing effectively creates strong sidelobes on absorption lines so that a strong apodization on the interferogram is recommended for the solar occultation experiment. These concepts are applied to retrieve pressure and temperature simultaneously from stratospheric absorption spectra in the CO(2) 4.3-microm band obtained by a balloon-borne interferometer in 1976 over Palestine, Tex. Included in the analysis of the CO(2) 4.3-microm band are the continuum absorptions by the pressure-induced N(2) fundamental band and by far wings of the CO(2) v(3) band. The CO(2) absorption line is corrected by a sub-Lorentzian function. Excellent agreement is found between the observed and simulated spectra.

The synthesis of deuterium-substituted, spin-labeled analogues of AMP and NAD+ and their use in ESR studies of lactate dehydrogenase

Two spin-labeled analogues of AMP and NAD+ were synthesized, in which a perdeuterated nitroxide radical (4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, TEMPAMINE) was attached to C-6 or C-8 position of the adenine ring. The ESR spectra of these derivatives exhibit a 4-fold increase in sensitivity and a concomitant decrease in line-width as compared to the corresponding protonated analogues. The improved resolution of composite spectra consisting of freely tumbling and immobilized components is demonstrated in ternary complexes of the spin-labeled NAD+ derivatives with lactate dehydrogenase (L-lactate:NAD+ oxidoreductase, EC 1.1.1.27) and oxalate.

Three-dimensional digital subtraction angiography

A dye-edge tracking algorithm was used to determine the corresponding points in the two images (anterior-posterior and lateral) of the digital subtraction biplane angiography. This correspondence was used to reconstruct three-dimensional images of cerebral arteries in a dog experiment and a clinical observation. The method was tested by comparing the measured image of oblique view to the computed reconstructed image. For the present study, we have developed three new algorithms. The first algorithm is to determine the corresponding dye-edge points using the fact that the density of contrast media at the moving edge shows the same changing pattern in the two projection views. This moving pattern of dye-edge density is computed using a matching method of cross correlation for the two sequential frames' dye density. The second algorithm is for simplified perspective transformation, and the third is to identify the corresponding points using a complementary method for locating the approximate points on the small vessels. The present method can be applied to compute the velocity of blood flow using the dye-edge displacement and the three-dimensional distance data.

Stratospheric measurements of continuous absorption near 2400 cm(-1)

Solar occultation spectra obtained with a balloon-borne interferometer have been used to study continuous absorption by N(2) and CO(2) near 2400 cm(-1) in the lower stratosphere. Synthetic continuum transmittances, calculated from published coefficients for far-wing absorption by CO(2) lines and for pressure-induced absorption by the fundamental band of N(2), are in fair agreement with the observed stratospheric values. The continuum close to the nu(3) R-branch band head of CO(2) is sensitive to the CO(2) far-wing line shape. Therefore, given highly accurate knowledge of the N(2) continuum from laboratory data, high-resolution stratospheric spectra provide a sensitive means for in situ testing of various air-broadened CO(2) line shapes at low temperatures.

Structural and motional changes in glyceraldehyde-3-phosphate dehydrogenase upon binding to the band-3 protein of the erythrocyte membrane examined with [15N,2H]maleimide spin label and electron paramagnetic resonance

Binding of the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase [GAPDHase; D-glyceraldehyde-3-phosphate:NAD+ oxidoreductase (phosphorylating EC 1.2.1.12], to the cytoplasmic segment of band-3 protein in the erythrocyte (RBC) membrane has been examined by electron paramagnetic resonance (EPR) and saturation transfer EPR (ST-EPR) spectroscopies. GAPDHase, which was isolated from rabbit muscle and labeled with the resolution-enhancing deuterated N-(15N-1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)maleimide spin label ([15N,2H]MSL), showed the same binding specificity for the transmembrane band-3 protein of human erythrocyte membranes as reported for unlabeled GAPDHase from human RBC. Experimental EPR lineshapes from soluble and membrane-bound enzymes were analyzed by direct stimulation of spectra and indicated a structural alteration of the bound GAPDHase in the vicinity of the spin label, which was attached covalently to the active-site cysteine-149 residue. A rigorous theoretical analysis of the ST-EPR spectra of soluble and membrane-bound enzyme is presented and utilized in conjunction with model system analysis to demonstrate that the motion of membrane-bound GAPDHase could be characterized by an effective isotropic rotational correlation time of 20 microseconds. This indicated that the GAPDHase--band-4 complex exhibits motional freedom relative to the membrane-spanning segment of the band-3 protein or the RBC. The double substituted spin label [15N,2H]MSL affords gains in sensitivity and resolution that permit studies of membrane-bound enzymes at physiological levels and quantitative simulations of the EPR and ST-EPR lineshapes with reasonable computation times.

15N- and 2H-substituted maleimide spin labels: improved sensitivity and resolution for biological EPR studies

The resolution and sensitivity of electron paramagnetic resonance (EPR) and saturation transfer EPR (ST-EPR) for biological applications are greatly improved by deuteration and substitution of (15)N for (14)N in the spin-labeled probe N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)maleimide (MSL). The EPR and ST-EPR spectra of the deuterated analogue [(2)H]MSL and the (15)N-substituted and deuterated derivative [(15)N, (2)H]MSL were compared with those of the parent MSL. The [(15)N, (2)H]MSL showed the greatest gain in sensitivity and the most marked sharpening of spectral features. These improvements were due to (i) a reduction in the spectral linewidths resulting from the relatively weak hyperfine interactions of the unpaired electron with deuterium and (ii) spectral simplification due to a reduction in the number of nuclear manifolds from three to two in replacing (14)N with (15)N. In the freely tumbling state, the spectra of [(15)N, (2)H]MSL and [(2)H]MSL showed 10-fold and 5-fold increases, respectively, in signal heights compared to MSL. To study the slow tumbling frequencies characteristic of biological molecules, the MSL and its derivatives were covalently bound to the enzyme glyceraldehyde-3-phosphate dehydrogenase [GAPDHaase; D-glyceraldehyde-3-phosphate:NAD(+) oxidoreductase (phosphorylating), EC 1.2.1.12] on cysteine-149 of the catalytic site. The EPR and ST-EPR spectra of [(15)N, (2)H]MSL and [(2)H]MSL adducts showed 3- and 1.5-fold gains in sensitivity, respectively. More important, there were striking increases in resolution, particularly for [(15)N, (2)H]MSL over MSL. These improvements were observed throughout the correlation time range from 0.1 musec to 1 msec. The EPR spectrum of [(15)N, (2)H]MSL-GAPDHase at X-band showed no overlap of the two nuclear manifolds; therefore, all the elements of the A and g tensors could be measured directly from the spectrum. The increase in sensitivity and resolution of the (15)N- and deuterium-substituted spin labels permitted quantitative simulation of the EPR and ST-EPR spectra of a labeled protein. Computation time was reduced 90% by (15)N substitution. Use of (15)N-substituted and deuterated spin probes substantially improved characterization of the motional properties of a protein.

Solar occultation sounding of pressure and temperature using narrowband radiometers

A technique for simultaneously retrieving pressure and temperature profiles using satellite-based narrow-band radiometer measurements of absorption in the CO(2) 4.3-microm band is described. Pressure and temperature profiles for earth's upper atmosphere on a global scale can be obtained with errors <3% and 3 K, respectively. The p - T information can be used not only for improving the accuracy of inverted gas concentrations in the same absorption experiment but also for investigating the upper atmosphere circulation.

Enhancement of free radical reduction by elevated concentrations of ascorbic acid in avian dystrophic muscle

It has been postulated that the degenerative process in dystrophic muscle results from increased concentrations of free radicals, peroxides, or lipid hydroperoxides. Therefore, the reduction of the free radical tanol (2,2,6,6-tetramethyl-4-piperidinol-1-oxyl) by extracts of muscles of dystrophic and normal chickens was studied. Pectoral (white) and thigh (red) muscles were used. For initial rate measurements, the various muscle extracts were added to an equal volume of 0.2 mM tanol. Reaction mixtures were introduced into the EPR cavity in a standard aqueous flat cell. Rates were measured by continuously monitoring the decrease in signal amplitude of the center (MI = 0) solution tanol EPR resonance line (in-phase first harmonic absorption signal). With extracts from dystrophic white muscle, the reduction rate was 75% faster than normal, whereas in dystrophic red muscle extracts the rate was normal. This agreed with previous observations that white muscle is more severely affected than red in dystrophic chickens. The primary reductant was identified as reduced ascorbic acid, and the rate of reduction of tanol correlated directly with the concentrations of ascorbic acid in the various muscle extracts as shown by chemical analysis. The results suggest an involvement of the intracellular redox status in the pathogenesis of avian muscular dystrophy.

The increase in hexokinase activity in hereditary avian muscular dystrophy

Hexokinase activity was found to be increased in both the more severely affected red (thigh) muscle of dystrophic chickens. The increase in activity was largely associated with the particulate fraction. These findings may indicate early events in the pathogenesis of avian muscular dystrophy.

Pressure sensing of the atmosphere by solar occultation using broadband CO(2) absorption

A technique for obtaining pressure at the tangent point in an IR solar occultation experiment is described. By measuring IR absorption in bands of atmospheric CO(2) (e.g., 2.0 microm, 2.7 microm, or 4.3 microm), mean pressure values for each tangent point layer (vertical thickness 2 km or less) of the atmosphere can be obtained with rms errors of less than 3%. The simultaneous retrieval of pressure and gas concentration in a remote-sensing experiment will increase the accuracy of inverted gas concentrations and minimize the dependence of the experiment on pressure or mass path error resulting from use of climatological pressure data, satellite ephemeris, and instrument pointing accuracy.

Treatment of Duchenne's muscular dystrophy with penicillamine. Results of a double-blind trial

Eleven boys with Duchenne's muscular dystrophy, randomly assigned to placebo (group A, n = 6) or penicillamine treatment (group B, n = 5), received three capsules per day containing lactose or 250 mg of penicillamine. All patients received pyridoxine, 50 mg daily. Mean age at entrance into study was similar for both groups (group A , 86.7 +/- 31.6 months; group B, 95.4 +/- 43.4 months). Clinical status was assessed with timed functional activities, manometric measurements of muscle force, and manual muscle testing. After 14 to 16 months of treatment, statistical analysis (analysis of variance) of data disclosed no significant differences in the overall performance of the two groups. A longer-duration trial, involving younger patients, is needed to determine whether there are palliative effects of penicillamine or other potentially therapeutic agents.

Mechanism of action of penicillamine in the treatment of avian muscular dystrophy

Penicillamine, a cysteine analog with a reduced sulfhydryl group, has been used in this laboratory for the treatment of hereditary avian dystrophy. The drug delays the onset of symptoms and alleviates the debilitating aspects of the disease. To study the mechanism of drug action, the effects of penicillamine on white and red muscles of dystrophic chickens were examined with regard to the specific activities of the soluble enzymes glyceraldehyde-3-phosphate dehydrogenase, acetylphosphatase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glutathione reductase, glutathione preoxidase, superoxide dismutase, and catalase. The sulfhydryl contents of the soluble proteins and the concentration of myoglobin were also determined. In white dystrophic muscle (pectoral), there were large alterations in the various enzymatic activities compared to normal levels. In the DISCUSSION, these changes are related to the pathogenesis of the disease and to the adaptive response for protection of the severely affected fast fibers. Red dystrophic muscles (thigh) were minimally involved, in accordance with the known sparing action of the slow fiber type. The results suggested that the disease process in dystrophic muscle may be due to oxidation of the essential sulfhydryl groups of proteins. Penicillamine may produce therapeutic effects by altering the intracellular redox status, thereby promoting better regulation of enzymatic activity, membrane stability, and improved muscle function.

Altered tissue carnitine levels in animals with hereditary muscular dystrophy

Low levels of muscle carnitine have been found in patients with Duchenne dystrophy, a case possibly of Becker dystrophy, and limb-girdle syndrome as well as in patients with the recently described muscle carnitine deficiency syndrome. Tissues of the mouse, hamster, and chicken were analyzed to determine whether tissue carnitine levels were altered in the animal models of muscular dystrophy. Significantly higher levels of carnitine were found in dystrophic mouse muscle, but carnitine levels in plasma, liver and heart were normal. Histological changes in the skeletal muscle of dystrophic hamsters were relatively mild, and both skeletal muscle and plasma levels were normal. The liver carnitine level was higher than normal levels. The dystrophic hamster also had an inherited cardiomyopathy, and interestingly its heart carnitine level was much lower than normal. The red muscle of the normal chicken contained 5 times the level of carnitine found in white muscle. The dystrophic chicken had higher than normal levels of carnitine in the white muscle, but normal levels in the red muscle. Although all 3 animal models of muscular dystrophy studied have altered levels of carnitine in some tissue, none of the animal models had the same pattern of altered tissue carnitine levels seen in human patients.

Erythrocyte membrane abnormalities in Duchenne muscular dystrophy monitored by saturation transfer electron paramagnetic resonance spectroscopy

Saturation transfer electron paramagnetic resonance and the spin label 2-(3-carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl were used to study erythrocytes from patients with Duchenne muscular dystrophy or Becker syndrome and from age-matched normal boys. There were significant differences in the spectral intensities of erythrocytes from Duchenne patients when compared to controls. Spectral intensities increased with time in the former; no such change was observed in the latter. Saturation transfer electron paramagnetic resonance spectra of erythrocytes from patients with Becker syndrome were significantly different from those from Duchenne patients but were not significantly different from normals. These observations suggest the possible usefulness of these techniques in the differential diagnosis of Duchenne muscular dystrophy. Spin label concentration spectral studies suggest that the observed spectral differences between Duchenne patients and controls were due to differential spin exchange phenomena.

Global monitoring of stratospheric halogen compounds from a satellite using gas filter spectroscopy in the solar occultation mode

We have analyzed the gas filter radiometer approach for long-term monitoring of stratospheric HCl, HF, CH(4), and H2O using solar occultation at selected intervals in the 2-6 microm range. Our analysis shows that this instrument technique is feasible. This conclusion is based on a simulation study in which we evaluated the effect of various experiment errors on retrieval accuracy. The instrument errors used were based on measurements made on a breadboard model gas filter radiometer. The results show that HCl and HF can be measured with an rms error of 10% and CH(4), and H2O with an error of 15% over the 10-30-km range.

Penicillamine treatment of hereditary avian muscular dystrophy

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Enzymological studies on hereditary avian muscular dystrophy

White and red muscles of normal and genetically dystrophic chickens were compared with regards to activity levels of three soluble enzymes, glyceraldehyde-3-phosphate dehydrogenase, creatine phosphokinase, and acetyl phosphatase. In dystrophic white muscle (pectoral), activity of the two sulfhydryl enzymes, glyceraldehyde-3-phosphate dehydrogenase and creatine phosphokinase, was preferentially lost from the sarcoplasm resulting in decreased specific activities. By contrast, acetyl phosphatase was preferentially retained and showed increased specific activity. Dystrophic white muscle had decreased sulfhydryl content in the soluble proteins, severe reduction in muscle mass, fatty infiltration, and fragmentation of fibers. Red dystrophic muscles (thigh) were minimally involved in accordance with the known sparing of red fibers. Enzyme activities were correlated with histological observations. The results suggested that the disease process in dystrophic white muscle may be related to alterations in the sulfhydryl groups of proteins. The data are correlated with the beneficial effects of our treatment of hereditary avian dystrophy with the sulfhydryl compound, penicillamine (Chou, T.H., Hill, E.J., Bartle, E., Woolley, K., LeQuire, V., Olson, W., Roelofs, R., and Park, J.H. (1975) J. Clin. Invest. 56, 842-849).

Cysticercosis in otolaryngology

Cysticercosis is not likely to be the first diagnosis the otologist has in mind when regarding tumors in the head and neck area. The fact that this disease may present a diagnostic and therapeutic problem is illustrated by three cases, appearing in the tongue, buccal mucosa, and midline of the neck, respectively. The local finding of a soft nontender mass, the typical calcifications in the soft tissues visible on roentgenograms, and the histopathological findings are described and illustrated. Attention is drawn to the fact that cerebral cysticercosis, which is a very grave disease, may cause tinnitus, nystagmus, and hearing disturbances.

Beneficial effects of penicillamine treatment on hereditary avian muscular dystrophy

Hereditary muscular dystrophy in chickens of the New Hampshire strain was treated with penicillamine from the 9th day after hatching to the 425th day. The adult maintenance dose for males was 50 mg/kg per day and for females, 13-65 mg/kg per day. In avian dystrophy, deterioration of the muscle fibers is evidenced in the 2nd mo by an inability of the birds to rise after falling on their backs and by a progressive rigidity of the wings. The drug delayed the onset of symptoms and partially alleviated the debilitating aspects of the disease. Penicillamine produced three major improvements: (a) better righting ability when birds were placed on their backs; (b) greater wing flexibility; (c) and suppression of plasma creatine phosphokinase activity. The results are statistically analyzed and discussed in relationship to Duchenne dystrophy. Normal birds were not affected by penicillamine as judged by these parameters. The rationale for using penicillamine, a sulfhydryl compound with reducing properties, was (a) to attempt to protect essential thiol enzymes in the anabolic and glycolytic pathways against inactivation and (b) to prevent collagen cross-linking and deposition in muscle. Although the precise mechanism of drug action has not been determined. the possible role of penicillamine in mitigating the symptoms of genetic dystrophy in man is under consideration. Further, penicillamine may have a more generalized application i the prevention of contractures in a variety of neuromuscular disorders.

Covalent binding of 3-pyridinealdehyde nicotinamide adenine dinucleotide and substrate to glyceraldehyde 3-phosphate dehydrogenase

Glyceraldehyde 3-phosphate dehydrogenase (D-glyceraldehyde-3-phoshate:nicotinamide adenine dinucleotide oxidoreductase (phosphorylating), EC 1.2.1.12) forms a complex with 3-pyridinealdehyde-NAD which survives precipitation with 7% perchloric acid. The molar ratio bound 3-pyridinealdehyde-NAD to the enzyme is 2.5 to 2.9. Lactate, malate, and alcohol dehydrogenases do not form acid-precipitable complexes with 3-pyridinealdehyde-NAD. 3-Pyridinealdehyde-deamino-NAD or glyceraldehyde 3-phosphate also forms an acid-stable complex with glyceraldehyde 3-phosphate dehydrogenase; however, NAD, 3-acetylpyridine-NAD, or thionicotinamide-NAD does not produce an acid-stable complex. Incubation of the glyceraldehyde 3-phosphate dehydrogenase with glyceraldehyde 3-phosphate, acetyl phosphate, iodoacetic acid, or iodosobenzoate inhibits the formation of the acid-stable complex with 3-pyridinealdehyde-NAD. Glyceraldehyde 3-phosphate or 3-pyridinealdehyde-NAD also prevents carboxymethylation of the active site cysteine-149 by[14-C]iodoacetic acid. These studies indicate that the aldehyde group of 3-pyridinealdehyde-NAD forms a thiohemiacetal linkage with cysteine-149 which is the substrate binding site for the dehydrogenase reaction. These findings may account for the fact that 3-pyridinealdehyde-NAD strongly inhibits the dehydrogenase and esterase activities of 3-pyridinealdehyde-NAD forms a thiohemiacetal linkage with cysteine-149 which is the substrate binding site for the dehydrogenase reaction. These findings may account for the fact that 3-pyridinealdehyde-NAD strongly inhibits the dehydrogenase and esterase activities of glyceraldehyde 3-phosphate dehydrogenase which require reduced cysteine-149. However, the analogue does not inhibit the acetyl phosphates activity of the enzyme for which the active site sulfhydryl residues must be oxidized.