Dictionary,Defintion,Meaning,What is Lesch Nyhan Syndrome,Leucine Zipper,Leaky Mutations,Lecitin Cholesterol Acyltransferase,Lectinomics

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Dictionary of Bioinformatics, Biotechnology, Biochemistry Dictionary of Bioinformatics, Biotechnology, Biochemistry Part 1 Part 2 Part 3 Immunoprecipitation - In Vitro Translation Inculsion Bodies - Inflammatory Response Infra Red Spectroscopy (IR Spectroscopy) - Insertion Site; Cloning Site Insulin Hypoglycaemia Test - Integration Integrins - Intermittent Branched Chain Ketonuria Intracellular Signalling - Ion Exchange Chromatography Ionomics - Isoniazid (Isonicotinic acid hydrazide, INH) Isotope Coded Infinity Tag (ICAT) Jak STAT Signallinig Pathway - Juxtacrine Signalling K Homology Domain - Khorana, Har Gobind Kimmelsteil-Wilson Syndrome - Knudson's Two-hit Hypothesis Kronberg Roger Lac Opern Lactate Dehydrogenase (LD) Laron Type Dwarfs - Late Genes Lesch Nyhan Syndrome - Leucine Zipper Limit Digest - Lineweaver Burk-Equatuion Lipid Storage Diseases (lipidoses) - Lipofection Localisome - Long accurate PCR (LA-PCR) Low Molecular weight (LMP) - Lundh test Lysosome M Phase Promoting factor (MPF) - Magnetic Resonance Imaging (MRI) Malabsorption - Maple Syrup Urine Disease (MSUD) Marasmic Kwashiorkor - Maturation Promoting Factor (MPF)

Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >>Lesch Nyhan Syndrome Leucine Zipper

	Leaky mutations Mutations that allow some basal level of gene expression. Leaving group The molecular group that is displaced in a unimolecular elimination or a bimolecular substitution reaction. Lecithin A common name for the membrane phospholipids phosphatidyl choline. Lecithin has detergent properties and is capable of dissolving cholesterol in arterial plaques. Lecithin (Phosphatidyl Choline)
Lecithin cholesterol acyltransferase (LCAT) See LCAT. Lectinomics The study of carbohydrate-biding proteins, excluding sugar-specific antibodies, receptors of free mono-or disaccharides for transport or chemotaxis and enzymes modifying the bound carbohydrate. Lectins Agglutinating proteins generally extracted from plants. These proteins bind oligosaccharides on cell surface with very high affinity and specificity. The cause cells to clump together (agglutinate) and mediate cell-cell interactions. Lederberg, Joshua (1925) A bacterial geneticist credited with the discovery of transduction by bacteriophage. He also devised the technique of replica plating to analyse genetic linkage and recombination in bacteria. He was awarded the Nobel Prize in Physiology or Medicine in 1958.
Left splicing junction The boundary between the right end of an exon and the left end of an intron. Legume A member of the pea family, which is a rich source of nitrogen stored in the form of nitrates. The roots of the leguminous plants have a symbiotic relationship with nitrogen fixing bacteria. Leiners disease Biotin deficiency in young infants characterised by exfoliative dermatitis and persistent diarrhoea. Leiomyoma A benign tumour of the smooth muscle. Lentivirus A retrovirus that causes chronic, subclinical infection that evokes an immune response resulting in demyelination of nerve cells. An example of a lentivirus is the visna virus that infects the brain cells of sheep.
Leptotene The stage in meiosis that immediately precedes synapsis. In this phase, the chromosomes appear as single, fine, threadlike structures. Lesch-Nyhan syndrome A rare, X-linked recessive disorder due to a complete deficiency of hypoxanthine guanine phosphoribosyl transferase (HGPRT) identified by Michael Leach and William Nyhan in 1964. It is characterised by mental retardation, loss of coordination, self-mutilation, choreoathetosis and other neurological signs and symptoms. Lethal allele A mutant form of a gene that ultimately results in the death of an organism if expressed in the phenotype. Also called lethal gene. Lethal dose The dose of the agent required to cause 100% mortality when administered to test animals.
	Lethal gene See lethal allele. Lethal locus A location in a gene in which a leaky mutation can be obtained as a result of gene deletion. Lethal mutation A mutation that inactivates a vital function essential for the survival of the cell or organism. Lethal zygosis Refers to the killing of female cells by conjugal transfer when the male: female rations increase. Leucine A branched chain amino acid. See amino acids. Leucine-rich repeat protein (LRR protein) A common receptor serine/threonine kinase in plants that is characterised by a tandem array of leucine-rich repeat sequences in the extracellular region.

Leucine-sensitivity hypoglycaemia Hypoglycaemia in children that is precipitated by casein, which has a high leucine content. Leucine is a stimulant of insulin secretion.

Leucine zipper A structural motif that is involved in protein-protein interactions in eukaryotic regulatory proteins. It contains two interacting α-helices with leucine residues in every seventh position.

Leucine Zipper

Leucine Zipper

Leucocyte See white blood cell.

Leukaemia Malignant disease characterised by the proliferation of leukocytes and their precursors in the blood and bone marrow.

Leukocyte adhesion deficiency (LAD) Immune deficiency in which one or more adhesion molecules are not expressed.

Leukocytopenia A decrease in the number of leukocytes in the blood.

Leukodystrophy A disturbance of the white substance of the brain.

Leukotrienes Molecules derived from arachidonate. These cause muscle contraction and bronchospasm.

Leventhal paradox A paradox that states that a random search through the infinite number of alternative denatured conformation of a protein would take an infinite length of time.

Levorotatory isomer A stereoisomer that rotes the plane of polarised light to the left.

LexA A protein that regulates the SOS system. The protein inhibits the expression of about 17 din genes involved in DNA repair. Damage to DNA produces an inducing signal causing self-cleavage of lexA protein. As a result, the SOS genes are expressed.

LexA repressor A protein that regulates the SOS system. During normal growth, the SOS functions associated with DNA repair are not expressed due to inhibition by lexA repressor. LexA repressor also inhibits its own expression as well as that of recA. Following DNA repair, the lexA repressor levels are increased and the SOS genes return to their usual repressed state.

Lexicon In bioinformatics, refers to a predefined list of terms that together completely defines the contents of a particular database.

Leydig cells (interstitial cells) Cells found scattered between the tubules that secrete testosterone in response to luteinising hormone (LH).

LHRH See GnRH.

Library (gene library). 1. A collection of cells (bacteria or yeast) that have been transformed by the introduction of recombinant vectors carrying DNA inserts from a single species. 2. Set of cloned fragments representing the entire genome. See cDNA library; expression library; genomic library; bank; gene bank.

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Dictionary of Bioinformatics, Biotechnology, Biochemistry Part 4 Part 5 Part 6 Part 7 Maxam Gilbert Sequencing - Meiosis Membrane Bioreactors - Meristem Culture Messenger RNA (mRNA) - Metal Chelate Chromotography Methaemoglobin (MetHb) - Methylation Specific (PCR) Microamplification - Microdroplet Array Microheterogenity - Microtiter Test Microtubule associated Proteins (MAPs) - Mismatch Repair Mitochondrial Precursor Protein - Mobile Introns Modification Interference - Molecular Imprinting Molecular Modelling Database (MMDB) - Monogenetic Disorders Monte Carlo Algorithms - Multidimensional Protein Identification Technology (MudPIT) Multiforked Chromosome - Mutation Frequency Allele Frequency Mutator Phenotype - Myxoedema Nanobioteechnology National Human Genome Research Institute (NHGRI) - near Patient Testing Nephelometry - Nephrotic Syndrome Neurofibromatosis - Neurotransmitter