Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adenylyl-(5'leads to N)-amino acids containing as amino components, methyl esters of D-, L- and DL-phenylalanine, D-, L- and DL-tyrosine, and D-, L- and DL-tryptophan have been investigated by proton magnetic resonance (PMR) spectroscopy and circular dichroism (CD). The temperature and pD dependences of proton chemical shifts of these compounds have been studied. These data, together with the magnitudes of the upfield chemical shifts of the PMR signals of adenine and aromatic amino acids residues in adenylyl-(5'leads to N)-amino acids, have enabled us to construct conformational models of these compounds. The proposed conformation has been substantiated by the CD results. It is shown that in adenylyl-(5'leads to N)-amino acids the planes of adenine and amino acid aromatic moieties are roughly parallel. The aromatic rings of phenylalanine and tyrosine are localized approximately above the centre of adenine. In adenylyl-(5'leads to N)-D, -(L)-tryptophan, the six-membered rings of the indole overlaps the five-membraned ring of adenine indole partially overlaps the six-membered ring of adenine. A difference in the non-covalent interactions of D- and L-amino acids with nucleotides has been revealed. The mutual localization of the aromatic systems of AMP and the amino acids and also the positions of -OCH3 group with respect to the centre of the amino acid aromatic moiety differs in the series of the studied nucleotide derivatives of D- and L-amino acids.
Mol Biol (Mosk)
PMID:[The secondary structure of amides of adenylic acid containing D- and L-aromatic amino acids]. 94 May 56

Exposure of dilute aqueous solutions of tryptophan to near UV light (320 to 390 nm) at subsolar levels yields fluorescent photoproducts capable of inhibiting the growth and differentiation of cultured mouse embryonic fibroblasts and fertilized sea urchin eggs. The ability of these cells to incorporate labelled precursors of protein, RNA, and DNA into their respective macromolecules was markedly inhibited by adding tryptophan preirradiated with near UV light to their incubation media. Thus the inhibition of growth and differentiation of these cells seems to result from a depression of their ability to synthesize macromolecules in the presence of the photoproducts.
Mol Cell Biochem 1976 Feb 25
PMID:Inhibition of cell growth by near ultraviolet light photoproducts of tryptophan. 94 71

Mutant penicillinase plasmids, in which penicillinase synthesis is not inducible by penicillin or a penicillin analogue, were examined by biochemical and genetic analyses. In five of the six mutants tested, penicillinase synthesis could be induced by growth in the presence of 5-methyltryptophan. It is known that the tryptophan analogue 5-methyltryptophan is readily incorporated into protein by S. aureus and that staphylococcal penicillinase lacks tryptophan. 5-methyltryptophan seems to induce penicillinase synthesis in wild-type plasmids by becoming incorporated into the repressor and thereby inactivating the operator binding function of the penicillinase repressor. Therefore, induction of penicillinase synthesis in the mutant plasmids by 5-methyltryptophan strongly suggests that the noninducible phenotype of these five plasmids is due to a mutation that inactivates the effector binding site of the penicillinase repressor (i.e., the five mutant plasmids carry an iS genotype for the penicillinase repressor). This conclusion was supported by heterodiploid analysis. The mutant plasmid that did not respond to 5-methyltryptophan either produces an exceedingly low basal level of penicillinase or does not produce active enzyme. This plasmid seems to carry a mutation in the penicillinase structural gene or in the promoter for the structural gene. Thus, a genetic characterization of many mutations in the penicillinase operon can be accomplished easily and rapidly by biochemical analysis.
Mol Gen Genet 1976 Aug 10
PMID:Characterization of mutations in the penicillinase operon Staphylococcus aureus. 95 3

The methods which have been used for the observation and assignment of resonances in the NMR spectra of proteins are reviewed. One such method, the selective deuteration of the aromatic protons of tryptophyl residues, is studied by NMR spectroscopy in model compounds in this paper, and in proteins in the following paper. On the basis of a reassignment of the PMR spectrum of the aromatic protons of L-tryptophan, the relative rates of H-D exchange in deutero-trifluoracetic acid (d-TFA) are H-2 greater than H-5 greater than H-6 greater than H-4 approximately H-7. The energies of activation for the first order exchange of both the H-2 and H-5 protons is 12 k.cal.mol-1. The rate constant for exchange of the H-2 protons of tryptophyl residues in peptides is much greater than in the amino acid itself and 5-10 times that for exchange of the H-5 protons. This suggests that the method can be used to label tryptophyl residues in proteins rapidly and specifically.
Mol Cell Biochem 1976 Aug 30
PMID:Kinetics of hydrogen-deuterium exchange of tryptophan and tryptophan peptides in deutero-trifluoroacetic acid using proton magenetic resonance spectroscopy. 95 13

Variations in size and charge of calf lens proteins, particularly gamma crystallins, were studied by polyacrylamide gel electrophoresis. Exposure of gamma crystallins to near-UV light in the presence of L-tryptophan produces species of higher electrophoretic mobility and higher retardation. Treatment with urea and sulfonation also produced changes in the retardation co-efficient. The increase of retardation co-efficient of gamma crystallin is interpreted to be a result of conformational changes. Gamma crystallins are particularly sensitive to photo-modification, and this process may be associated with age-related changes in the lens.
Mol Cell Biochem 1976 Jul 30
PMID:Modification of calf lens crystallins as determined by gel electrophoresis. 96 62

The reaction of iodine with aromatic residues of hen egg white lysozyme is examined by means of natural abundance 13C nuclear magnetic resonance spectroscopy. In the unfractionated product of the reaction at PH 5.5 (with I2/lysozyme molar ratios of 0.5, 1.0, and 2.5), the only detectably modified aromatic residues are Trp-108 and either Tyr-20 or Tyr-23 (probably the latter). The rates of reaction at the two sites are similar. The extents of modification (at each site) are approximately 25%, 50%, and approximately greater than 80% for I2/lysozyme molar ratios of 0.5, 1.0, and 2.5, respectively. At pH 4.5, the rates of reaction of both residues are about one-third or less of the rates at pH 5.5. When the reaction is carried out at pH 8.5 (with an I2/lysozyme molar ratio of 1.0), only the tyrosine residue is modified. Resonances observed in the spectra of the modified protein mixtures (but not in the spectrum of intact lysozyme) indicate that the modified Trp-108 residue is not oxindolealanine, but either delta1-hydroxytryptophan or an ester thereof. This result is consistent with previous evidence which indicates that the modified tryptophan is the Glu-35 ester of delta1-hydroxytryptophan-108 (Imoto, T., and Rupley, J.A. (1973) J. Mol. Biol. 80, 657-667; Beddell, C. R., Blake, C. C. F., and Oatley, S. J. (1975) J. Mol. Biol. 97, 643-654). The spectra also indicate that the modified tyrosine residue is predominantly monoiodinated. The spectra of modified protein samples subjected to denaturation with 6M guanidinium chloride for 24 h at 37 degrees (and the renatured) indicate that residue 108 is converted to about equal amounts of the two diastereoisomers of oxindolealanine. However, incubation in 6M guanidinium chloride for 2 h at 25 degrees does not cause measurable hydrolysis of the Glu-35 ester of delta1-hydroxytryptophan-108.
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PMID:Studies of chemical modifications of proteins by carbon 13 neuclear magnetic resonance spectroscopy. Reaction of hen egg white lysozyme with iodine. 98 24

The deuteration of the tryptophan residues of hen egg white lysozyme, bovine alpha-lactalbumin and bovine beta-lactoglobulin in d-TFA has been studied by PMR spectroscopy. It is found that short times of exposure to d-TFA allow selective deuteration at the C-2 position with only a small amount of deuteration at the C-5 position, as expected from studies on model peptides described in the previous paper. The proteins studied essentially regained their native structures after the treatment, except for broadening and shifting of the histidine resonances in the case of alpha-lactalbumin. Selective deuteration at the tryptophan C-2 position was readily observed by difference spectroscopy of the denatured protein, but PMR difference spectra of the same proteins in benign solvents did not contain resonances from all of the exchanged protons. Some resonances would not be observed because of line broadening, which causes the resonances to fall below the limit of sensitivity of detection at 100 MHz. Deuteration by brief exposure to d-TFA should be useful for the identification of tryptophan resonances in the PMR spectra of native proteins. The deuteration of all the aromatic protons of tryptophan residues in proteins by immersion in d-TFA for 4 hours at room temperature was studied. This technique is unlikely to be of general use for the simplification of the aromatic region of the PMR spectra of native proteins because of the degradation of tryptophan residues which results from the acid treatment.
Mol Cell Biochem 1976 Nov 30
PMID:Proton magnetic resonance spectroscopic studies of proteins containing deuterated tryptophan residues. 100 98

Reaction rates for ATP-PPi isotope exchange (vex) and tryptophanyl-tRNA formation (vaa) catalysed concomitantly in one incubation mixture by beef pancreas tryptophanyl-tRNA synthetase (trsase) have been examined as a function of substrate concentrations. Comparison of the vex/vaa ratio found experimentally with the ratio predicted theoretically conforms the mechanism suggested earlier and permits to describe it in more detail. I. At least two reaction routes exist in which an ATP-PP: exchange is allowed. These routes are interconnected with each other via the stage at which tRNA binds to the enzyme. 2. In both these routes the low molecular weight substrates bind with enzyme in the order ATP first, tryptophan second. 3. Enzyme-aminoacyladenylate complex is an intermediate in the reaction of aminoacyl-tRNA formation. Pyrophosphate is detached from the enzyme prior to tRNA. 4. The enzyme releases AMP and tryptophanyl-tRNA in a random fashion. All the aformentioned properties are common both for trigger mechanism and Yarus-Berg mechanism which up to now were considered in literature independently.
Mol Biol (Mosk)
PMID:[Kinetic model describing the action of tryptophanyl-tRNA-synthetase]. 105 75

The non-histone chromatin proteins (NHP) were isolated by a modified Wang technique. NHP were easily dissoluble in solutions of a physiological ionic strength within a wide pH range. NHP were subdivided into 18 zones by analytical polyacrylamide gel electrophoresis. NHP have molecular weights within the range 15,000 greater than 200,000. A part of NHP showed similar molecular weight but different values of molecular charge. NHP were separated by a gel filtration into 6 fractions. Two fractions were individual proteins. The great bulk of NHP has a molecular weight less than 40,000, and 6-6.5% of NHP-more than 100,000. The fractions different from each other in a specific UV-absorbtion, fluorescence and circular dichroism. The nhp fraction of a smaller molecular weight has a smaller content of alpha-helix (8%) and the greatest polarity of the environment of tryptophan residues; the molecules of this fraction may have a loose tertial structure. Other NHP have 15-24% of alpha-helix and possibly have compact globular sites.
Mol Biol (Mosk)
PMID:[Partial fractionation and physico-chemical properties of non-histone chromatin proteins]. 105 76

Equilibrium constants (K) of the complex formation of adenosine-5'-phosphate with phenylalanine (27 l/mol) and tryptophan (67 l/mol) in water (D2O, pD 9.9) have been determined. The comparison of the equilibrium constant values allowed to find the sequence of probabilities of the approach of aromatic amino acids to adenosine-5'-phosphate (tryptophan greater than tyrosine greater than phenylalanine). It has been shown that the dependence of lg K on l/T in the system phenylalanine-adenosine-5'-phosphate is non-linear. The ranges of the positive values of enthalpy (deltaH) and entropy (deltaS) changes of the complex phenylalanine-adenosine-5'-phosphate formation in the temperature interval 28-65 degrees have been found (deltaH = 0.2-1.5 kcal/mol, delta S = 14-50 e.u.). The conclusion about the hydrophobic interaction of aromatic cycles of nucleotide and amino acids has been deduced from the received data.
Mol Biol (Mosk)
PMID:[Intermolecular interaction of adenosine-5'-phosphate with phenylalanine and tryptophan by nuclear magnetic resonance]. 105 79


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