Male sex hormone (androgen) secreted by the interstitial cells of the testis of mammals and responsible for triggering the development of sperm and of many secondary sexual ...
Thiol-activated haemolysin released by the bacterium Clostridium tetani.
Disease caused by the bacterium Clostridium tetani, spores of which persist in soil, but can proliferate anaerobically in an infected wound. Disease entirely due to ...
Neurotoxin released by Clostridium tetani ; becomes active when peptide cleaved proteolytically to heavy (100 kD) and light (50 kD) chains held together by ...
Potent local anaesthetic.
Broad-spectrum antibiotic that blocks binding of aminoacyl-tRNA to the ribosomes of both Gram positive and Gram negative organisms (and those of organelles). Produced by ...
Four homologous chromatids paired together during first meiotic prophase. More generally, any group of four objects.
A monovalent cation widely used in neurophysiology as a specific blocker of potassium channels. It is similar in size to the hydrated potassium ion, and gets stuck (reversibly) ...
Genus of ciliate protozoa frequently used in studies on ciliary axonemes, self-splicing RNA and telomere replication.
Nucleus, cell or organism that has four copies of the normal haploid chromosome set.
A potent neurotoxin (319 D) from the Japanese puffer fish. It binds to the sodium channel, blocking the passage of action potentials. Its activity closely resembles that of ...
General term for a monosaccharide with 4 carbon atoms.
Protein neurotoxin (70 kD) from venom of Pseudonaja textilis textilis that blocks neuromuscular transmission. All five subunits of the toxin have some phospholipase A2 ...
Transcription factor that binds to TATA box.
Transcription factor, one of the first to be cloned and characterized. Has a crucial role in transcription of 5S ribosomal RNA. Multiple cysteine/histidine zinc finger motifs. ...
Transcription factor consisting of TBP and two other proteins. An initiation factor required by RNA polymerase III; TFIIIA and TFIIIC assist its binding to the appropriate DNA ...
Transcription factor; large (500 kD) complex containing at least 5 subunits.
Any one of a number of accessory proteins involved in the binding of RNA Polymerase II to DNA in association with TBP.
See transforming growth factor.
(= Tec homology domain)
Proline-rich domain characteristic of Tec family protein kinases, probably ligand region for SH3 domain.
Hereditary blood disease in which there is abnormality of the globin portion of haemoglobin. Widespread in Mediterranean countries.
Sedative drug that when taken between 3rd and 5th week of pregnancy produced a range of malformations of the foetus, in severe cases complete absence of limbs (amelia), or much ...
Simple plant body, not differentiated into stem, root etc. Main form of the gametophyte generation of simpler plants such as liverworts.
Cell-permeable inhibitor of calcium ATPase of endoplasmic reticulum; leads to increase in cytoplasmic calcium ions. Acts independently of InsP3. A tumour promoter.
Protein from the African plant Thaumatococcus daniellii. It tastes 105 times sweeter than sucrose.
(= 3,7-dimethyl xanthine)
Principal alkaloid of cacao bean; has similar properties to theophylline and caffeine.
Inhibits cAMP phosphodiesterase, and is often used in conjunction with exogenous dibutyryl cyclic-AMP to raise cellular cAMP levels. Other, less ...
Form of calorimetry in which the rate of heat flow (or some other property) to a solid is measured as a function of temperature.
thermal melting profile
In general a record of the phase state of a system over a temperature range. Phase changes can be detected by exothermy or endothermy. Valuable in studying lipid and DNA ...
The study of energy and energy flow in closed and open systems.
Heat-stable metalloproteinase (EC 220.127.116.11.) produced by a strain of Bacillus stearothermophilus. Retains 50% of its activity after 1h at 80°C.
An organism that thrives at high temperature. The most extreme examples (hyperthermophiles) are cyanobacteria from hot-springs that have optima of 50-55°C, and will tolerate ...
A directed motile response to temperature. The grex of Dictyostelium discoideum shows a positive thermotaxis.
Aerobic Gram negative bacillus that lives in hot springs and was the source of Taq polymerase.
(= TPP; carboxylase)
The coenzyme form of vitamin B1 (thiamine), deficiency of which causes beri-beri. Forms the prosthetic group of pyruvate dehydrogenase, ...
Co-carboxylase. A cofactor that has an unusually acidic carbon atom able to form carbon-carbon bonds. Found in pyruvate dehydrogenase and transketolase.
Bipolar myosin-II filaments (12-14nm diameter, 1.6 m m long) found in striated muscle. Myosin filaments elsewhere are often referred to as ‘thick filaments’, although ...
Tendency of an organism or part of an organism to turn towards or respond to a mechanical stimulus.
Filaments 7-9nm diameter attached to the Z-discs of striated muscle, have opposite polarity in each half-sarcomere. Built of F-actin with associated tropomyosin and troponin. ...
thin layer chromatography
Chromatography using a thin layer of powdered medium on an inert sheet to support the stationary phase. Faster than paper chromatography, gives higher resolution, and ...
Compounds of the type. R-CO-S-R\'. See coenzyme A, palmitoylation.
The bond R-S-C, of which the best example is in methionine.
(= oxygen-labile haemolysins)
Cytolytic bacterial exotoxins that act by binding to cholesterol in cell membranes and forming ring-like complexes that act as pores. SH-groups ...
Group of small, hydrophobic plant proteins of 45-50 residues that are toxic to animals.
Intercellular disulphide-reducing enzyme. Also secreted by a variety of cells, despite the lack of a signal sequence, in a manner resembling the alternative secretory pathway ...
Glycogen storage disease in which the missing enzyme is phosphoglucomutase. See lysosomal diseases.
The major efferent lymph duct into which lymph from most of the peripheral lymph nodes drains. Recirculating lymphocytes that have left the circulation in the lymph node return ...
Human monocytic cell line derived from peripheral blood of 1-year-old boy with acute monocytic leukaemia. Have Fc and C3b receptors and will differentiate into macrophage-like ...
(= Thr; T; 119 D)
The hydroxylated polar amino acid.
A four-carbon sugar in which the two central hydroxyl groups are in trans orientation ( cis in erythrose).
Condition in which there is defective platelet aggregation, though adherence is normal. See Glanzmann\'s thrombasthenia.
Protease (34 kD) generated in blood clotting that acts on fibrinogen to produce fibrin. Consists of two chains, A and B, linked by a disulphide bond. B-chain has sequence ...
Gross deficiency in platelet number, consequently a tendency to bleeding.
In severe thrombocytopenia, bleeding into skin leads to small petechial haemorrhages. In primary thrombocytopenic purpura an autoimmune mechanism seems to cause platelet ...
(= b thromboglobulin)
Protein derived from platelet basic protein.
Specific endothelial cell receptor (100 kD: luminal surface only) that forms a 1:1 complex with thrombin. This complex then converts protein C to Ca, that in turn acts on ...
Traditional name for substance in plasma that converts prothrombin to thrombin. Now known not to be a single substance. (See thrombin).
Growth factor (19D) that regulates the proliferation of megakaryocytes and production of platelets (thrombopoiesis). Receptor is c-mpl, a cytokine receptor that can cause ...
Formation of a solid mass (a thrombus) in the lumen of a blood vessel or the heart.
Homotrimeric glycoprotein (450 kD) from a granules of platelets, and synthesized by various cell types in culture. Also found in extracellular matrix of cultured endothelial, ...
Obsolete name for platelet contractile protein: now known to be actomyosin (which makes up 15-20% of the total platelet protein).
Arachidonic acid metabolites produced by the action of thromboxane synthetase on prostaglandin cyclic endoperoxides. Thromboxane A2 (TxA2) is a potent inducer of platelet ...
Solid mass that forms in a blood vessel, usually as a result of damage to the wall. The first aggregate is of platelets and fibrin, but the thrombus may propagate by clotting ...
(= CDw90; formerly theta antigen)
Differentiation antigen (19 kD glycoprotein) on surface of T-cells, neurons, endothelial cells and fibroblasts. GPI-anchored and a member of ...
Membranous cisternae of the chloroplast, found as part of the grana and also as single cisternae interconnecting the grana. Contain the photosynthetic pigments, reaction ...
The excision of the thymus by operation, radiation or chemical means.
A lack of T-lymphocytes, due to failure of the thymus to develop, resulting in very reduced cell-mediated immunity though serum immunoglobulin levels may be ...
Term that is always used in practice for the nucleoside thymine deoxyriboside; not the riboside which naming of the other nucleosides might lead one to expect.
A method for synchronizing cells in culture. In the absence of thymidine, DNA synthesis cannot occur, so cells are blocked before S-phase; release of the block allows ...
Enzyme of pyrimidine salvage, catalysing phosphorylation of thymine deoxyriboside to form its 5\' phosphate, the nucleotide thymidylate. Animal cells lacking this enzyme can ...
(= 2,6-di-hydroxy, 5-methylpyrimidine; 5-methyluracil)
Pyrimidine base found in DNA (in place of uracil of RNA).
Dimer that can be formed in DNA by covalent linkage between two adjacent ( cis ) thymidine residues, in response to ultraviolet irradiation. Occurrence potentially mutagenic, ...
Lymphocyte within the thymus; term usually applied to an immature lymphocyte.
Biologically active pentapeptide corresponding to residues 32-36 of thymopoietin. Will induce prothymocytes and activate peripheral T-cells.
Peptide (28 amino acids) that restores aspects of immune function in vivo and in vitro. Possibly a thymic hormone.
Small protein (5 kD: 43 residues) found in large amounts in many vertebrate cells (approximately 0.2 mM in neutrophils) and that binds G-actin thereby inhibiting ...
The lymphoid organ in which T-lymphocytes are educated, composed of stroma (thymic epithelium) and lymphocytes, almost entirely of the T-cell lineage. In mammals the thymus is ...
The 650 kD protein of the thyroid gland that binds thyroxine.
Thyroxine and tri-iodothyronine are hormones secreted by the thyroid gland in vertebrates. These iodinated aromatic amino acid compounds influence growth and metabolism and, in ...
Long-acting thyroid stimulator is an autoantibody found in many cases of primary thyrotoxicosis which causes hyperplasia of the thyroid by undetermined mechanisms. Human ...
(= TSH; thyrotropin)
Polypeptide hormone (28 kD), secreted by the anterior pituitary gland, that activates cyclic AMP production in thyroid cells leading to production and ...
Disease of the thyroid, especially Hashimoto\'s disease, in which autoimmune destruction of the thyroid takes place.
(= protirelin; TRH; thyroliberin; TRF)
Tripeptide (pyroGlu-His-Pro-NH2) that releases thyrotropin from the anterior pituitary by stimulating adenyl cyclase. May also have ...
(= T4; tetra-iodothyronine)
See thyroid hormones.
Plasmid of Agrobacterium tumefaciens, transferred to higher plant cells in crown gall disease, carrying the T-DNA that is incorporated into the plant cell genome. Used as a ...
(= Tie1; Tie2/Tek)
Endothelium-specific receptor tyrosine kinase required for normal embryonic vascular development and tumour angiogenesis. Associates with p85 of PI3kinase. ...
See tissue inhibitors of metalloproteinases.
See tonoplast intrinsic protein.
Group of cells, often of mixed types and usually held together by extracellular matrix, that perform a particular function. Thus, tissues represent a level of organization ...
Originally the maintenance and growth of pieces of explanted tissue (plant or animal) in culture away from the source organism. Now usually refers to the (much more frequently ...
tissue culture plastic
Polystyrene that has been rendered wettable by oxidation, a treatment that increases its adhesiveness for cells from animal tissues, and without which anchorage -dependent ...
Integral membrane glycoprotein of around 250 residues, that initiates blood clotting after binding factors VII or VIIa.
tissue plasminogen activator
(= TPA; tPA)
Plasma serine protease, one of a closely related group of plasminogen activators. Contains an EGF-like domain and multiple copies of the kringle domain.
The process of determining the allelic types of the antigens of the major histocompatibility complex (MHC) that determine whether a tissue graft will be accepted or rejected. ...
Family of enormous proteins (2000-3500 kD) found in the sarcomere of striated muscle. Form a scaffolding of elastic fibres that may be important for correct ...
The mouse antigens coded for by the TLa complex; in normal animals only found on intrathymic lymphocytes, but also seen on leukaemic cells (hence, thymus leukemia antigen) in ...
Genes coding for and controlling TL antigens; the complex is situated close to the H-2 complex on mouse chromosome 17 and resembles H-2 in several ways.
(= thin layer chromatography)
Chromatographic separation method in which a thin layer of the solid phase (often silica, aluminium oxide or cellulose) is fixed onto a glass or ...
(= tosyl lysyl chloromethylketone)
Protease inhibitor, particularly effective against trypsin and papain.
Inhibitor of the release of calcium from intracellular stores.
See tobacco mosaic virus.
(= TNF-R; CD120)
There are two receptors for TNFa. Type I (CD120a; 55 kD) is present on most cell types and Type II (CD120b; 75 kD) is mainly restricted to haematopoietic cells. ...
tobacco mosaic virus
Plant RNA virus, the first to be isolated. Consists of a single central strand of RNA (a helix of 6500 nucleotides) enclosed within a coat consisting of 2130 identical ...
Transport system of the outer membrane of the chloroplast. Analogous to Tom complex though proteins are not the same. Toc75 seems to form the pore, Toc159 and Toc 34 are ...
(= a-tocopherol; vitamin E)
Protects unsaturated membrane lipids from oxidation and may prevent free-radical damage.
Class IV viruses with a single positive strand RNA genome. Bullet-shaped capsid, enveloped by a membrane formed from the host cell plasma-membrane; the budded membrane contains ...