Biomaterial Database

Electronic transitions in molecules in static external fields. I. Indole and Trp-59 in ribonuclease T1. 1988

P Ilich, and P H Axelsen, and F G Prendergast

Department of Biochemistry and Molecular Biology, Mayo Graduate School, Mayo Foundation, Rochester, MN 55905.

Electronic transition properties of indole perturbed by its environment were calculated by use of quantum-mechanical semi-empirical numerical methods. The environment was represented by a discrete set of charges placed at different positions around the indole ring. Wavelength shifts and transition intensity changes in indole were evaluated for several, specifically modeled geometries of external charges. This methodology was employed to estimate the extent of spectroscopic changes induced by small nonprotein polar species on the Trp-59 residue in the anisotropic environment of the protein ribonuclease T1. The geometry of the residue environment was obtained from dynamically equilibrated X-ray crystallographic data of the protein.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011789	Quantum Theory	The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E	Quantum Theories,Theories, Quantum,Theory, Quantum
D004722	Endoribonucleases	A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.	Endoribonuclease
D006163	Ribonuclease T1	An enzyme catalyzing the endonucleolytic cleavage of RNA at the 3'-position of a guanylate residue. EC 3.1.27.3.	Guanyloribonuclease,RNase T1,Ribonuclease N1,Aspergillus oryzae Ribonuclease,Guanyl-Specific RNase,RNase Apl,RNase F1,RNase Pch 1,RNase ST,Ribonuclease F1,Ribonuclease F2,Ribonuclease ST,Ribonuclease T-1,T 1 RNase,Guanyl Specific RNase,RNase, Guanyl-Specific,RNase, T 1,Ribonuclease T 1,Ribonuclease, Aspergillus oryzae
D014364	Tryptophan	An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.	Ardeydorm,Ardeytropin,L-Tryptophan,L-Tryptophan-ratiopharm,Levotryptophan,Lyphan,Naturruhe,Optimax,PMS-Tryptophan,Trofan,Tryptacin,Tryptan,Tryptophan Metabolism Alterations,ratio-Tryptophan,L Tryptophan,L Tryptophan ratiopharm,PMS Tryptophan,ratio Tryptophan
D014961	X-Ray Diffraction	The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Xray Diffraction,Diffraction, X-Ray,Diffraction, Xray,Diffractions, X-Ray,Diffractions, Xray,X Ray Diffraction,X-Ray Diffractions,Xray Diffractions