Structure records sequences from

The most obvious data in a typical 3D structure record are the atomic coordinate data, the locations in space of the atoms of a molecule represented by (x, y, z) triples, and distances along each axis to some arbitrary origin in space. The coordinate data for each atom are attached to a list of labeling information in the structure record such as that derived from the protein or nucleic acid sequence. 

The Protein Data Bank (PDB http //www.pdb.org) is the worldwide repository of three-dimensional structural data of biological macromolecules, such as proteins and nucleic acids (Berman et al. 2003). The Protein Data Bank uses several text file-based formats for data deposition, processing, and archiving. The oldest of these is the Protein Data Bank format (Bernstein 1977), which is used both for deposition and for retrieval of results. It is a plain-text format whose main part, a so-called primary structure section, contains the atomic coordinates within the sequence of residues (e.g., nucleotides or amino acids) in each chain of the macromolecule. Embedded in these records are chain identifiers and sequence numbers that allow other records to reference parts of the sequence. Apart from structural data, the PDB format also allows for storing of various metadata such as bibliographic data, experimental conditions, additional stereochemistry information, and so on. However, the amount of metadata types available is rather limited owing to the age of the PDB format and to its relatively strict syntax rules. 

The best somce of validated protein and nucleic acid sequences in single-letter code derived from PDB structure records is NCBFs MMDB service, which is part... 

In their fundamental paper on curve resolution of two-component systems, Lawton and Sylvestre [7] studied a data matrix of spectra recorded during the elution of two constituents. One can decide either to estimate the pure spectra (and derive from them the concentration profiles) or the pure elution profiles (and derive from them the spectra) by factor analysis. Curve resolution, as developed by Lawton and Sylvestre, is based on the evaluation of the scores in the PC-space. Because the scores of the spectra in the PC-space defined by the wavelengths have a clearer structure (e.g. a line or a curve) than the scores of the elution profiles in the PC-space defined by the elution times, curve resolution usually estimates pure spectra. Thereafter, the pure elution profiles are estimated from the estimated pure spectra. Because no information on the specific order of the spectra is used, curve resolution is also applicable when the sequence of the spectra is not in a specific order. 

Fig. 14. Typical signals of triglycerides in a proton spectrum, (a) Structure of a triglyceride with three different fatty acids (one saturated, two unsaturated). Different positions of protons in the molecule are indicated, resulting in different chemical shifts in the spectrum, (b) Characteristic signal pattern of triglycerides (or fatty acids) in a spectrum from yellow fatty bone marrow of the tibia, containing triglycerides in the adipocytes with more than 90% volume fraction. The spectrum was recorded with TE = 50 ms by a PRESS sequence.

Fig. 15. Comparison of a water suppressed muscle spectrum and a spectrum from yellow bone marrow containing almost pure fat (triglycerides). Measurement parameters STEAM sequence, TE=10 ms, TM=15 ms, TR = 2 s, 40 acq., VOI (11 X 11 X 20) mm. (a) Spectrum from TA muscle recorded after careful positioning of the VOI, avoiding inclusion of macroscopic fatty septa allows separation of extramyocellular (EMCL, broken lines) and intramyocellular lipid signals (IMCL, dotted lines) based on susceptibility differences. For this reason characteristic signals from fatty acids occur double. Signals of creatine (methyl, Crs, and methylene, Cr2) show triplet and doublet structure, respectively, due to dipolar coupling effects. Further signals of TMA (including carnitine and choline compartments), Taurine (Tau), esters, unsaturated fatty acids (-HC=CH-), and residual water are indicated, (b) Spectrum from yellow fatty bone marrow of the tibia with identical measuring parameters, but different amplitude scale.

Selected entries from Methods in Enzymology [vol, page(s)] Acquisition of frequency-discriminated spectrum, 239, 162-166, 170 sensitivity, 239, 169-173 constant-time, 239, 23-26 doublequantum filtered, 239, 236 gradient pulse experiments, 239, 185-189 protein structural information, 239, 377-379 pulse sequence and coherence transfer pathway, 239, 148-149 paramagnetic metalloprotein, 239, 494-497 data recording, SWAT method, 239, 166-169, 172 line shapes, effects of gradient pulses, 239, 162-166 identification of protein amino acid resonances, 232, 100 cyclosporin A, 239, 240-241. 

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