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G R Moore

Publications and source records attributed to G R Moore.

At least 163 records · Page 9Linked to original sources
PubMed1981

Structural studies of eukaryotic cytochrome c modified at methionine-65.

1H n.m.r. spectra were recorded in both oxidation states for the following species: tuna cytochrome c, tuna [carboxymethylmethionine-65]cytochrome c, horse cytochrome c and horse [homoserine-65]cytochrome c. The experiments give the assignments of the singlet methyl resonances of methionine-65 and the N-terminal acetyl group. The modification at methionine-65 is shown to cause an extremely small structural perturbation to one part of the molecule close to the site of modification.

Animals↗
PubMed1981

Nuclear magnetic resonance studies of Rhodospirillum rubrum cytochrome c'.

Cytochrome c' from Rhodospirillum rubrum has been studied by proton magnetic resonance (NMR) at 270 MHz. The pH and temperature-dependence properties as well as proton water relaxation enhancement and bulk susceptibility measurements were examined. We conclude that the fifth ligand to the iron is histidine. The pH-dependent shift of the heme methyl resonances of the ferric protein shows pKa's at 5.8 and 8.7. The low-pH equilibrium causes only minor changes in the properties of the protein. However, the high-pH equilibrium causes large changes throughout the NMR spectra which correlate with the reported visible spectral changes. These NMR spectral changes are compared with the low-temperature EPR and Mössbauer spectroscopic data. Analyses of the NMR data show that a second histidine, which is present in the sequence of c' from R. rubrum but is not conserved in other cytochromes c', is not a "distal" histidine. The nature of the sixth ligand and the significance of the high-pH transition are discussed.

Cytochrome c Group↗
PubMed1980

pH dependence of the redox potential of Pseudomonas aeruginosa cytochrome c-551.

The redox potential of Ps. aeruginosa cytochrome c-551 varies with pH between pH 5 and 8. The pH dependence can be analysed in terms of a pKa of 6.2 in the oxidised form and a pKa of 7.3 in the reduced form. The same pKa values are also observed in NMR spectra of the two oxidation states and the pKa of 7.3 is observed in titration of the visible absorption spectrum of the ferrocytochrome. From the NMR studies these pKa values have been assigned to the ionisation of one of the haem propionic acid groups. pH dependence of redox potential is of variable occurrence among cytochromes and the possible significance and basis of this variation is discussed.

Bacterial Proteins↗
PubMed1980

Nuclear magnetic resonance studies of the phenylalanine residues of eukaryotic cytochrome c.

The resonances of Phe 82 and Phe 10 in the nuclear magnetic resonance spectra of horse cytochrome c are reassigned using nuclear Overhauser enhancements. The reassignments provide new information about the oxidation state linked conformation change of cytochrome c. The region of the protein now known to be affected by the change extends to the part of the protein close to Phe 10.

Animals↗
PubMed1980

Nuclear-magnetic-resonance studies of eukaryotic cytochrome c. Assignment of resonances of aromatic amino acids.

The aromatic regions of the nuclear magnetic resonance spectra of horse ferricytochrome c and horse ferrocytochrome c are described. Resonance assignments have been made using NMR double-resonance techniques, spectral comparison of related proteins, the perturbing effects of extrinsic probes, and from knowledge of the X-ray structure of cytochrome c. 33 resonances arising from 39 aroumatic protons of ferrocytochrome c, and 18 resonances arising from 27 aromatic protons of ferricytochrome c have been assigned.

Amino Acids↗
PubMed1980

Nuclear-magnetic-resonance studies of eukaryotic cytochrome c. Assignment of resonances of aliphatic amino acids.

The aliphatic regions of the nuclear magnetic resonance spectra of horse ferricytochrome c and horse ferrocytochrome c are described. Resonance assignments have been made using NMR double-resonance techniques, spectral comparison of related proteins, the perturbing effects of extrinsic probes, and from knowledge of the X-ray structure of cytochrome c. There are eight firmly assigned methyl resonances of ferrocytochrome c and seven firmly assigned methyl resonances of ferricytochrome c.

Amino Acids↗
PubMed1980

Nuclear-magnetic-resonance studies of ferrocytochrome c. pH and temperature dependence.

The pH dependence and the temperature dependence of the nuclear magnetic resonance spectrum of horse ferrocytochrome c are described. This protein is very stable; it maintains an ordered structure over the pH range 4 to 12 at 25 degrees C and over the temperature range 4 degrees C to 97 degrees C at pH 7.0. The dynamic characteristics of the conformation of ferrocytochrome c were investigated. Particular emphasis was laid on the aromatic resonances and resonances of methyl groups shifted far upfield. Tyr-48 and Phe-46 were found to be relatively immobile whilst a region of the protein close to Ile-57 was found to be relatively flexible.

Amino Acids↗
PubMed1980

The stability of ferricytochrome c. Temperature dependence of its NMR spectrum.

The temperature dependence of the nuclear magnetic resonance spectrum of horse ferricytochrome c is described. The protein maintains an ordered structure over the temperature range 20 degrees C to 77 degrees C. The temperature dependence of the spectrum of ferricytochrome c arises from a number of causes including the paramagnetism of the ferric ion and protein structural changes. Preliminary analysis of the data show that the region of the protein about Ile-57 is flexible. Comparison of the data with the analogous data for horse ferrocytochrome c reveals that there is a small difference in structure between cytochrome c in its two oxidation states in the region about Ile-57.

Amino Acids↗
PubMed1980

The solution structures of tuna and horse cytochromes c.

The nuclear magnetic resonance spectra of tuna ferricytochrome c and tuna ferrocytochrome c are described. Resonance assignments are made using NMR double-resonance techniques. A comparison of the NMR data for tuna cytochrome c with the previously reported data for horse cytochrome c shows that the proteins have virtually identical main-chain folds. Three regions of local conformational differences have been distinguished.

Amino Acid Sequence↗
PubMed1980

Comparison of the structures of various eukaryotic ferricytochromes c and ferrocytochromes and their antigenic differences.

The nuclear magnetic resonance spectra of various eukaryotic ferricytochromes c and ferrocytochromes c are described. The proteins from the species donkey, cow, dog, rabbit, chicken and pigeon were investigated. The conformations of these proteins detected by NMR were compared to those of horse and tuna cytochromes c and in some cases small differences were found. These differences in structure were shown to correlate with antigenic differences between the various proteins.

Animals↗
PubMed1979

Osteogenesis imperfecta. A study of 160 family members.

Osteogenesis imperfecta, a genetic disease characterized by blue sclera, fragile bones, and hearing loss, was studied in 160 descendants of a single, affected individual. One hundred twenty family members in four generations were at risk of inheriting the gene for osteogenesis imperfecta. Fifty-six percent (68/120) had blue sclera, and, of this group, 66% had fragile bones, and 47% of those tested had hearing loss. The onset of hearing loss was usually in the second or third decade, and was primarily of the conductive type. The incidence of sensorineural hearing loss was only slightly less than the incidence of conductive hearing loss. To out knowledge, this is the largest reported kindred study of osteogenesis imperfecta. The genetic transmission of this disease as an autosomal dominant was confirmed.

Adolescent↗
PubMed1978

Structural homology of cytochromes c.

Cytochromes c from many eukaryotic and diverse prokaryotic organisms have been investigated and compared using high-resolution nuclear magnetic resonance spectroscopy. Resonances have been assigned to a large number of specific groups, mostly in the immediate environment of the heme. This information, together with sequence data, has allowed a comparison of the heme environment and protein conformation for these cytochromes. All mitochondrial cytochromes c are found to be very similar to the cytochromes c2 from Rhodospirillaceae. In the smaller bacterial cytochromes, Pseudomonas aeruginosa cytochrome c551 and Euglena gracilis cytochrome c552, the orientation of groups near the heme is very similar, but the folding of the polypeptide chain is different. The heme environment of these two proteins is similar to that of the larger bacterial and mitochondrial cytochromes. Two low-potential cytochromes, Desulfovibrio vulgaris cytochrome c553 and cytochrome c554 from a halotolerant micrococcus have heme environments which are not very similar to those of the other proteins reported here.

Amino Acids↗