Biomaterial Database

Time-resolved fluorescence and 1H NMR studies of tyrosyl residues in oxytocin and small peptides: correlation of NMR-determined conformations of tyrosyl residues and fluorescence decay kinetics. 1986

J B Ross, and W R Laws, and A Buku, and J C Sutherland, and H R Wyssbrod

Steady-state and time-resolved fluorescence properties of the single tyrosyl residue in oxytocin and two oxytocin derivatives at pH 3 are presented. The decay kinetics of the tyrosyl residue are complex for each compound. By use of a linked-function analysis, the fluorescence kinetics can be explained by a ground-state rotamer model. The linked function assumes that the preexponential weighting factors (amplitudes) of the fluorescence decay constants have the same relative relationship as the 1H NMR determined phenol side-chain rotamer populations. According to this model, the static quenching of the oxytocin fluorescence can be attributed to an interaction between one specific rotamer population of the tyrosine ring and the internal disulfide bridge.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008968	Molecular Conformation	The characteristic three-dimensional shape of a molecule.	Molecular Configuration,3D Molecular Structure,Configuration, Molecular,Molecular Structure, Three Dimensional,Three Dimensional Molecular Structure,3D Molecular Structures,Configurations, Molecular,Conformation, Molecular,Conformations, Molecular,Molecular Configurations,Molecular Conformations,Molecular Structure, 3D,Molecular Structures, 3D,Structure, 3D Molecular,Structures, 3D Molecular
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D010121	Oxytocin	A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.	Ocytocin,Pitocin,Syntocinon
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
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
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014443	Tyrosine	A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.	L-Tyrosine,Tyrosine, L-isomer,para-Tyrosine,L Tyrosine,Tyrosine, L isomer,para Tyrosine