beamline: In particle physics, a beamline is the line along which a beam of particles travels through, or when projected from, a particle accelerator. It may refer to the line of travel within an actual accelerator, and to the equipment that maintains that beam in a storage ring or accelerates it in a linear accelerator. It may also refer to a beam of X-rays projected to stations for doing crystallography  Beamline, Wikipedia, accessed Oct. 3, 2005  Google = about 240,000  June 7, 2004, about 1,210,000 Oct. 3, 2005  Related terms: synchrotrons, Industrial Macromolecular Crystallography Association IMCA 

bicelle: Bicelles are an attractive membrane mimetic system because of their planar surface and lipid composition, which resemble biological membranes. In addition, their  orientation and morphologic properties make them amenable to solid- and solution-state NMR. This article reviews the physical properties of bicelles, such as magnetic alignment and viscosity as well as the different models proposed in the literature to explain the bicelle morphology. The utility of bicelles for studying the interaction and structure of membrane peptides and proteins by solid- and solution-state NMR is also presented, along with the advantages and limitations of bicelles. Bicelles as Model Membranes for Solid and Solution-State NMR Studies of Membrane Peptides and Proteins ISABELLE MARCOTTE,1 MICHE` LE AUGER2 Concepts in Magnetic Resonance Part A, Vol. 24A(1) 17–37 (2005)  Published online in Wiley InterScience (www.interscience.wiley. com). DOI 10.1002/cmr.a.20025   http://sbl.unmc.edu/ncsb/journals/BicellesModelMembranesNMR.pdf  

¹³C : Carbon isotopes used in NMR labeling.

ClogP: Algorithms

COSY: Correlated Spectroscopy, 2D NMR.

chemical shift: The variation of the resonance frequency of a nucleus in nuclear magnetic resonance (NMR) spectroscopy in consequence of its magnetic environment. The chemical shift of a nucleus, is expressed in ppm by its frequency, cpd, relative to a standard, ref, and defined as = 106(cpd - ref)/o  where o is the operating frequency of the spectrometer. For ¹H and ¹³C NMR the reference signal is usually that of tetramethylsilane (SiMe4). Other references are used in the older literature and in other solvents, such as D2O.  If a resonance signal occurs at lower frequency or higher applied field than an arbitrarily selected reference signal, it is said to be upfield, and if resonance occurs at higher frequency or lower applied field, the signal is downfield. Resonance lines upfield from SiMe4 have positive, and resonance lines downfield from SiMe4 have negative -values. [IUPAC  Physical Organic Chemistry]

An atomic property that varies depending on the chemical and magnetic properties of an atom and its arrangement within a molecule. Chemical shifts are measured by NMR spectroscopists to identify the types of atoms in their samples. [NIGMS, US Structures of Life glossary, 2000 http://www.nigms.nih.gov/news/science_ed/structlife.pdf.  Google = about 68, 200 June 7, 2004NMR Nomenclature: Nuclear Spin Properties and Conventions for Chemical Shifts IUPAC Provisional Recommendations, Physical and Biophysical Chemistry Division, Commission Molecular Structure and Spectroscopy Comments by Aug. 21, 2001 http://www.iupac.org/reports/provisional/abstract01/harris_310801.html

chemical shift anisotropy CSA: A “relaxation” property. 

comparative spectral analysis CoSA: SEE under Quantitative ¹³C NMR Spectrometric Data- Activity Relationships Modeling QSDAR
comparative structural connectivity spectra analysis CoSCSA: SEE under Quantitative ¹³C NMR Spectrometric Data- Activity Relationships Modeling QSDAR
comparative structurally assigned spectral analysis CoSASA: SEE under Quantitative ¹³C NMR Spectrometric Data- Activity Relationships Modeling QSDAR 

cryogenic probe: One of the engineering challenges has been to cool the detection circuitry to these very low temperatures while maintaining the sample itself at ambient temperatures.  The first generation of these cryoprobes provides a factor of three improvement in signal- to- noise ratio, which means about a factor of nine or ten reduction in data collection time. Soon we will be able to combine the cryoprobes with the NOESY data collection and residual dipolar coupling to determine complete high- quality protein structures much faster. Related terms: cryoprobe, microcryoprobes, triple resonance cryoprobes.

cryoprobe ™ : Bruker has developed  high- performance cryogenic probes for high- resolution applications. These probes have improved signal/noise (S/N) ratios obtained by reducing the operating temperature of the coil and the pre- amplifier. The dramatic increase in the S/N ratio by a factor of  4, as compared to conventional probes, leads to a possible reduction in experiment time of 16  or a reduction in required sample concentration by a factor of 4.  [Bruker website] http://www.bruker.de/analytic/nmr-dep/probes/cryoprobe.htm  Related terms: cryogenic probe, microcryoprobes.

crystal: A regular repeat of molecules, usually with some sort of internal rotational symmetry. Protein crystals are usually about 40- 60% solvent by weight and are thus fragile and sensitive to drying out. [Robert L. Campbell, Protein crystallography: Important points and definitions. http://pldserver1.biochem.queensu.ca/~rlc/work/teaching/definitions.shtml 

crystallography: The branch of science that deals with the geometric description of crystals and their internal arrangement. [OMD]  

The study of the structures of molecules contained within crystals. A crystal is a solid that consists of millions of virtually identical tiny repeating units called "unit cells"; each unit cell is the same size, is oriented identically, and has the same contents, as every other unit cell. Typically the unit cell contains one or a small number of molecules. IMCA- CAT: A Layman's Introduction http://www.imca.aps.anl.gov/   Narrower terms: protein crystallography, X-ray crystallography, synchrotron- based x-ray crystallography  -- or are these equivalent?

crystallomics: -Omes & -omics

Dalton: Unit of mass equal to the unified atomic mass (atomic mass  constant). [IUPAC Compendium] After John Dalton (1766-1844) British chemist and physicist. more Chemistry

dephases: (Electricity.) To put out of phase, as two parts of a single alternating  current. [dictionary.com]  http://www.dictionary.com/cgi-bin/dict.pl?term=dephase

deuterium- decoupled triple- resonance NMR: Gives an improvement in sensitivity.  If you randomly change some of the hydrogens in the sample to deuterium, then all of the other peaks in the spectrum can be made sharper, and the pulse sequence can be designed to erase, or decouple, the resonance- splitting effects of deuterium. 

Electron Spin Resonance EST: Electron paramagnetic resonance (EPR) and electron spin resonance (ESR) can be viewed as two alternative names in a family of electron magnetic resonance (EMR) techniques. The measurements owe their origin to the magnetic properties of the electron which, since it has a magnetic moment (associated with the electron spin), will interact with an external magnetic field. Simply, the electron can behave like a small bar magnet when placed in a magnetic field, trying to align itself with the external field. It is then possible to cause the electron to 'flip' from alignment with the external field, to alignment against the field by irradiation with suitable microwave electromagnetic radiation. (Gigahertz, that is 10⁹Hz). Resonance techniques are generally used to measure this intriguing phenomenon, with the measurements finding uses in science topics as diverse as anthropology, the brewing industry, metalloenzyme biochemistry and the study of the electronic properties of molecules and atoms, Like its younger cousin, NMR, nuclear magnetic resonance, EMR is also developing as an imaging technique for magnetic resonance imaging (MRI).  ESR Electron Spin Resonance Group of the Royal Society of Chemistry, What's in a name? http://www.esr-group.org.uk/Name.html 

EMR Abbreviations http://www.esr-group.org.uk/Name.html#abbrev 

FT-NMR: Fourier Transform NMR: A major breakthrough occurred in 1966. Richard R. Ernst then discovered (together with Weston A. Anderson, USA) that the sensitivity of NMR spectra could be increased dramatically if the slow frequency sweep was replaced by short, intense radiofrequency pulses. The pulses cause a signal to be emitted by the nuclei. This signal is measured as a function of time after the pulse. It cannot be interpreted directly. Ernst discovered, however, that it was possible to extract the resonance frequencies from such a signal and to convert the signal into a NMR spectrum by a mathematical operation (Fourier* transformation, FT). This is performed rapidly in a computer. The whole process can be compared with stretching both arms over a piano and pushing all the keys at the same time. All the tones are there, but they are difficult to distinguish. A computer can discern the different tones (frequencies). Ernst's discovery is the basis of modern NMR spectroscopy, called FT NMR. It leads to a tenfold, and sometimes 100-fold increase in sensitivity since the pulse response contains information on all resonance frequencies at the same time. [Fourier-Transform NMR, Nobel e-Museum, 2001] http://www.nobel.se/chemistry/educational/poster/1991/fourier.html

flexible linkages: In proteins.

fluxome: Omes & omics
free induction decay FID: See spin, FT-NMR 
four-D: See 4D

¹H: Hydrogen isotope used in NMR labeling.

HMQC Heteronuclear Multiple Quantum Correlation: The HMQC experiment provides correlation between protons and their attached heteronuclei through the heteronuclear scalar coupling. This sequence is very sensitive (compare to the older HETCOR) as it is based on proton detection (instead of the detection of the least sensitive low gamma heteronuclei). NMR Course, Dept of Chemistry,  Queen's University, Kingston Ontario, Canada http://www.chem.queensu.ca/facilities/nmr/nmr/webcourse/hmqc.htm#hmqc 

hr-MAS High Resolution Magic Angle Spinning: The sample is spun at a high speed at a well-defined angle to the main magnetic field. Orienting the sample in this manner is a technique that was developed originally for solid state NMR to minimize the spectral line broadening introduced by intermolecular dipolar coupling or sample inhomogeneity. The appeal of hr-MAS is that it allows the study of systems that were previously not accessible with NMR. Some particularly interesting recent applications of this technology include the study of biological tissues and combinatorial chemistry samples that have been isolated on polymer beads.  [Aileen Constans "Taking It Higher: State- of- the- Art NMR technology offers answers for the solution and solid states" Scientist 14 (21): 26, Oct. 30, 2000]  http://www.the-scientist.com/yr2000/oct/profile1_001030.html  Broader term: MAS Magic Angle Spinning 

HSQC Heteronuclear single quantum correlation: The HSQC experiment have been proposed by Bodenhausen and Ruben (G. Bodenhausen and D. J. Ruben, Chem. Phys. Lett., 69, 185 (1980)). The HSQC experiment is in fact a double INEPT experiment. This experiment correlates protons with their directly attached heteronuclei. Proton magnetization is detected (during t2 - detection time) while the low-gamma nuclei evolves during the evolution time - t1. Because of the detection of the high frequency nuclei, this sequence is very sensitive. The enhancement in sensitivity this experiment permits is much greater than the enhancement obtainable by simple NOE (Nuclear Overhauser Effect). This is why this experiment have been referred to as the "OverBodenhausen" experiment. NMR Course, Dept of Chemistry,  Queen's University, Kingston Ontario, Canada http://www.chem.queensu.ca/facilities/nmr/nmr/webcourse/ 

high-field NMR: The spectra of complex biomolecules contain a large number of peaks, many of which are close together or overlap. Higher field magnets, or higher frequency instruments, offer better peak resolution, enabling analysis of larger and larger molecules. Also, in NMR, sensitivity increases almost with the square of the magnetic field, so when magnetic field strength is doubled, sensitivity increases about fourfold. Data can thus be acquired faster, or alternatively, samples can be run at lower concentrations in the same experimental time. The latter advantage is particularly important to the study of large biomolecules, which are often difficult to express and purify in large quantities and can aggregate and precipitate out of solution at high concentrations. Finally, high- field NMR can lead to the development of new NMR experiments that exploit properties exhibited by molecules at high magnetic fields.  [Aileen Constans "Taking It Higher: State- of- the- Art NMR technology offers answers for the solution and solid states" Scientist 14 (21): 26, Oct. 30, 2000]  http://www.the-scientist.com/yr2000/oct/profile1_001030.html

high pressure NMR: Advanced high-resolution NMR spectroscopy, including two-dimensional NMR techniques, combined with high pressure capability, represents a powerful new tool in the study of proteins. High-Resolution, High-Pressure NMR Studies of Proteins J. Jonas,* L. Ballard,# and D. Nash# Biophysical Journal Volume 75 July 1998 445–452 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1299717/pdf/9649405.pdf 

high-resolution diffusion-ordered spectroscopy HR-DOSY: Philip Hodge and Gareth Morris and their colleagues at the University of Manchester [are] using NMR to help them pick out the best host molecules from an array of hopefuls for use in analytical sensor applications. ... A multi- dimensional version of NMR, which disperses signals for the members of the library according to an additional criterion: their diffusion coefficients. Normally all the members will diffuse relatively rapidly. However, when a soluble polymer, with an added side-group of interest, is added to the combinatorial array, each member of the array that binds to the functionality on the polymer diffuses more slowly than before. The magnitude of the shift indicates the strength of the interaction. The spectrum of the most tightly bound molecule can then be plotted.  [Elemental Discoveries Mar. 2001, Issue 39] http://www.sciencebase.com/mar01iss.html

hyphenated techniques: NMR together with chromatography and/ or mass spectrometry. Includes LC- NMR. Google = about 12,500 June 7, 2004

Industrial Macromolecular Crystallography Association IMCA:  http://www.imca.aps.anl.gov/  Related terms: beamline, synchrotrons infrared spectromicroscopy: Microscopy

isotope: A form of a chemical element that contains the same number of protons but a different number of neutrons than other forms of the element. Isotopes are often used to trace atoms or molecules  in a metabolic pathway. In NMR, only one isotope of each element contains the correct magnetic properties to be useful.  [NIGMS, US Structures of Life glossary, 2000] http://www.nigms.nih.gov/news/science_ed/structlife.pdf.

J coupling: See spin-spin coupling.

kD: kilo Dalton. Also abbreviated kDa.

LC-NMR: Liquid Chromatography - Nuclear Magnetic Resonance: Nuclear magnetic resonance (NMR) detection coupled with liquid chromatography (LC) offers great promise in combining the ability to separate complex mixtures into individual components with one of the most structurally rich detection schemes available. [Bert Wang, Introduction to LC- NMR Technology, Wang NMR, Inc. 2002   http://www.wangnmr.com/LCNMR_technology.htm

MAD Multiwavelength Anomalous Diffraction : An approach to solving the phase problem in protein structure determination by comparing structure factors collected at different wavelengths, including the absorption edge of a heavy-atom scatterer. Also known as multiple-wavelength anomalous diffraction or multiwavelength anomalous dispersion.  International Union of Crystallography 2008 http://reference.iucr.org/dictionary/Multiwavelength_anomalous_diffraction_(MAD) 

A technique used in X-ray crystallography that accelerates the determination of protein structures. It uses X-rays of different wavelengths, relieving crystallographers from having to make several different metal- containing crystals.  NIGMS, US Structures of Life glossary, 2000 http://www.nigms.nih.gov/news/science_ed/structlife.pdf

MAS Magic Angle Spinning: NMR strategy in which the tube is rotated at very high speed and at a  specific angle which cancels out the line broadening effects of inhomogeneities in the sample. This yields high resolution and high sensitivity which are very useful in trace analysis or in looking at solid phase synthesis resins. IUPAC Combinatorial Chemistry

Has since long been proven powerful in the studies of heterogeneous samples such as powdered solids, compartmentalized liquid samples, or heterogeneous solid- liquid mixtures. Recently it has been shown that higher resolution could be achieved if high- resolution  magnetic-  susceptibility- matching probe (Nano.nmr probe) technology was used in conjunction to MAS High resolution liquid NMR and magic angle spinning. M. Delepierre ,”High Resolution Liquid NMR and Magic Angle Spinning” J. Chim. Phys., Vol. 95 (2) February 1998  http://www.edpsciences.org/articles/jcp/abs/1998/02/dele/dele.html  Google = about 12,800 June 7, 2004  Narrower term: hrMAS

macromolecular crystallography: The study of the structures of large biological molecules contained in crystals. "Large" in this context means that the molecules consist of 400 atoms and up. Biological macromolecules rarely exist as crystals in their natural state, so part of the science consists of coercing the molecules (usually proteins, but occasionally DNA and RNA molecules) to form crystals. Typical crystals of macromolecules are 10-500 microns (0.01 mm - 0.5 mm) in each dimension. IMCA- CAT: A Layman's Introduction http://www.imca.aps.anl.gov/

metabolomics: -Omes & -omics  metabonome, metabonomics: -Omes & -omics

MicroCryo Probes™ : Bruker offers these for 3 mm sample tubes. Traditionally, NMR samples are placed in 5 mm tubes, with a high solvent- to- sample ratio. With the increased sensitivity offered by accessories such as the CryoProbes, researchers have noticed more solvent impurities in their spectra. The 3 mm tubes and MicroCryoProbes allow spectroscopists to study mass- limited samples, such as natural products and metabolites, in less solvent.  [Aileen Constans "Taking It Higher: State-of-the-Art NMR technology offers answers for the solution and solid states" Scientist 14 (21): 26, Oct. 30, 2000]  http://www.the-scientist.com/yr2000/oct/profile1_001030.html

Based on cryogenically cooled receiver coils and electronics ... can make routine measurements in the nanogram range [Bruker BioSpin] http://www.bruker-biospin.com/nmr/products/crp_micro.html  Related terms: cryogenic probes, cryoprobe.

mmCIF dictionary Macromolecular Crystallographic Information File:  Background and introduction http://mmcif.rcsb.org/mmcif-early/background/index.html 

multidimensional (three- and four-dimensional) NMR: Introduced about 12-15 years ago. This technology has the advantage of resolving the severe overlap in 2D spectra and represents a very important breakthrough. Related terms:  3D NMR, 4D NMR

¹⁵N: Nitrogen isotope label for NMR.

NMR Nuclear Magnetic Resonance:  NMR spectroscopy makes it possible to discriminate nuclei, typically protons, in different chemical environments. The electron distribution gives rise to a chemical shift of the resonance frequency. The chemical shift, , of a nucleus is expressed in parts per million (ppm) by its frequency, n, relative to a standard, ref, and defined as = 106 (n - ref)/o, where o is the operating frequency of the spectrometer. It is an indication of the chemical state of the group containing the nucleus. More information is derived from the spin- spin couplings between nuclei, which give rise to multiplet patterns. Greater detail may be derived from two- or three- dimensional techniques. These use pulses of radiation at different nuclear frequencies, after which the response of the spin system is recorded as a free- induction decay (FID). Multi- dimensional techniques, such as COSY and NOESY, make it possible to deduce the structure of a relatively complex molecule such as a small protein (molecular weight up to 25 000). In proteins containing paramagnetic centres, nuclear hyperfine interactions can give rise to relatively large shifts of resonant frequencies known as contact and pseudo- contact (dipolar) shifts, and considerable increases in the nuclear spin relaxation rates. From this type of measurement, structural information can be obtained about the paramagnetic site. [IUPAC Bioinorganic]

A technology for protein structure determination. NMR generally gives a lower- resolution structure than X-ray crystallography does, but it does not require crystallization. NMR is currently applicable only to smaller proteins. Narrower terms:  2D NMR, 3D NMR, 4D NMR, COSY, deuterium decoupled triple resonance NMR, high field NMR, LC-NMR, multidimensional NMR, NMR - biomolecular, NOESY, ROESY, reduced dimensionality triple resonance NMR, SAR by NMR, STD NMR, solid state NMR, solution state NMR, TOCSY, TROSY, FT-NMR Fourier Transform NMR triple resonance NMR.  Related term: ESR Electron Spin Resonance
Spectroscopy Now, NMR Knowledge Base, John Wiley & Sons, Ltd., UK http://www.spectroscopynow.com/coi/cda/home.cda?chId=5

NMR active atom: An atom that has the correct magnetic properties to be useful for NMR. For some atoms, the NMR-active form is a rare isotope, such as ¹³C or ¹⁵N. [NIGMS, US Structures of Life glossary, 2000 http://www.nigms.nih.gov/news/science_ed/structlife.pdf

IUPAC definitions are reprinted with the permission of the International Union of Pure and Applied Chemistry.