Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0009443 (cold)
 92,137 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hormone-sensitive lipase (HSL) in brown adipose tissue from mice was identified through immunoprecipitation with a polyclonal antibody (anti-HSL) towards rat white fat HSL and Western blotting. An 82 kDa polypeptide, slightly smaller than the rat white fat HSL 84 kDa subunit, was detected and its identity as HSL verified by inhibition properties. The HSL concentration per g tissue was several-fold higher in the mouse brown adipose tissue than in the rat white adipose tissue, but the specific activities per mg protein were similar. Cold-exposure (4 degrees C) of the mice for 24 h approximately doubled the HSL concentration but this increase parallelled the overall protein increase and did not reflect a specific effect on the HSL.
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PMID:Hormone-sensitive lipase in brown adipose tissue: identification and effect of cold exposure. 332 36

Stability is frequently a knife-edge phenomenon and it is this aspect which is both essential for the effective involvement of macromolecules in the living cell and also provides the basis for the sensitivity of some macromolecular systems to temperature. The response of proteins and nucleic acids is relatively simple at the phenomenological level, with rather sharp 'melting' transitions occurring. Since however the thermodynamic stability of both depends on the cooperation of a variety of non-covalent interactions which are qualitatively well understood but quantitatively difficult to assess, the full understanding and prediction of structural stability still evades us. We shall consider the effects of temperature on the different non-covalent interactions and how far these can account for protein and nucleic acid denaturation at elevated temperatures and also the cold inactivation of proteins. The latter has recently been shown to involve unsuspected complications in terms of protein conformational change. The increased stability of proteins and nucleic acids from thermophiles will be discussed. Stability is important not only in native folded proteins but also with respect to intermediate structures which occur during the folding of the newly synthesized polypeptide chain into the native, active protein. Through studies of protein folding the molecular basis of the phenomenon of temperature sensitive synthesis has been revealed. Given a stable molecular structure, its function will frequently be subject to variation with temperature. The deceptively simple temperature dependence of enzyme activity will involve the non-covalent interactions considered above for interaction between enzyme and substrate and for stability of the transition state complex. This complexity again makes the temperature dependence difficult to interpret. Further, the fact that proteins are dynamic structures is becoming recognized as an important feature factor in determining function. A balance has to be struck between on the one hand dynamic mobility which is essential for catalytic activity and on the other thermodynamic stability which holds the molecule in a potentially functional conformation under the given conditions of temperature and pressure. Readjustment of thermostability stability, as in thermophiles (or vice versa?), must also involve readjustment of dynamic mobility.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Temperature and macromolecular structure and function. 333 85

To investigate the functions of the paraventricular nucleus (PVN) which plays an important role as an integration site for the neuroendocrine and autonomic nervous systems, the firing activity of PVN neurons was recorded from hypothalamic slice preparations during thermal, osmotic and chemical stimulation. Neurons responded to environmental factors such as temperature and osmolarity and both warm-responsive and cold-responsive neurons were observed in the PVN. Some PVN neurons were also osmoresponsive and unlike neurons in the supraoptic nucleus, most osmoresponsive PVN neurons decreased their firing rate during hyperosmotic stimulation. One of the classical transmitters, noradrenaline, exerted excitatory effects on PVN neurons through alpha 1- and beta-receptors and inhibitory responses through alpha 2-receptors. Atrial natriuretic polypeptide exerted inhibitory effects on putative parvocellular PVN neurons but it had no effect on putative magnocellular PVN neurons. An endogenous sugar derivative, 2-deoxytetronic acid, thought to be an endogenous satiety factor, elicited inhibitory effects, supporting the possibility that the PVN also may be related to feeding behaviour. Arginine-vasopressin and oxytocin which are synthesised in the magnocellular neurosecretory cells excited PVN neurons, suggesting that the PVN may have short circuits modulating neural activity within the nucleus itself. We conclude that neurons in the PVN may receive multiple information and act as one of the important integrative sites in the brain.
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PMID:Thermal, osmotic and chemical modulation of neural activity in the paraventricular nucleus: in vitro studies. 340 58

The localization of vasoactive intestinal polypeptide (VIP) immunoreactivity in canine distal oesophagus was studied using different fixation and embedding procedures and labelling with protein A-gold. The retention of immunoreactivity and the preservation of ultrastructure was best after fixation with a mixture of 0.1% glutaraldehyde and 4% paraformaldehyde, and embedding in 'LR White' resin using the 'cold-cured' method. VIP immunoreactivity was localized exclusively over large granular vesicles in the myenteric plexus and in nerves of the circular muscle. Most varicose profiles in circular muscle were labelled, but some large granular vesicles in the same profiles which contained labelled vesicles as well as some varicose profiles with large granular vesicles were unlabelled. From these data it was uncertain whether unlabelled large granular vesicles contained VIP or other neuropeptides. A striking finding was the dense and close innervation of the interstitial cells of Cajal with nerve containing VIP-labelled large granular vesicles. This finding is consistent with earlier suggestions that VIP-immunoreactive nerves may innervate these cells which are in gap junction contact with smooth muscle and that this arrangement may be involved in the transmission of non-adrenergic, non-cholinergic nerve activity in distal oesophagus.
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PMID:Ultrastructural localization of VIP-immunoreactivity in canine distal oesophagus. 345 Jul 87

The capacity of microtubules to disassemble in vitro is profoundly affected by a protein factor designated STOP (stable tubule only polypeptide). Here we report the isolation of STOP protein and confirm that its activity is, as predicted, highly substoichiometric to the tubulin in microtubules. The isolation of the 145-kDa STOP (STOP145) protein has been effected from isolated cold-stable microtubules by two column steps: DEAE ion-exchange and a calmodulin affinity column. To confirm the protein's activity we have produced an antibody against STOP145 and have used the antibody to specifically remove the protein and the activity using an antibody-linked affinity column. We conclude that the STOP145 protein accounts for the observed in vitro stabilization of microtubules.
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PMID:Purification and assay of a 145-kDa protein (STOP145) with microtubule-stabilizing and motility behavior. 345 61

We have previously shown that platelet glycoprotein Ib is expressed in a minority of cells of the human leukemic cell line HEL (Tabilio, A., Rosa, J. P., Testa, U., Kieffer, N., Nurden, A. T., Del Canizo, M. C., Breton-Gorius, J., and Vainchenker, W. (1984) EMBO J. 3, 453-459). In this report, we have selected a stable HEL subclone with increased expression of glycoprotein (GP) Ib as assessed by 6 different monoclonal antibodies in order to investigate the biochemical characteristics of this glycoprotein. A single polypeptide chain of apparent Mr = 60,000 was precipitated under reducing and nonreducing conditions by a specific polyclonal anti-platelet glycocalicin antibody and two anti-GPIb alpha monoclonal antibodies (AN51 and AP1), both from surface-labeled and metabolically labeled HEL cells. We were unable to demonstrate the presence of a polypeptide corresponding to the beta subunit of GPIb or GPIX which is closely associated with GPIb. Competitive immunoprecipitation performed in the presence of an excess amount of cold platelet glycocalicin completely displaced the Mr = 60,000 polypeptide. Synthesis of N-linked oligosaccharide chains on this Mr = 60,000 polypeptide was inhibited by the antibiotic tunicamycin, and a shift of the apparent Mr from 60,000 to 48,000 was observed. O-Linked oligosaccharide chains identical to platelet GPIb hexasaccharides were deficient or incomplete since no peanut agglutinin binding to the Mr = 60,000 polypeptide was observed after neuraminidase treatment of HEL cells. Thus, our results provide evidence that the Mr = 60,000 polypeptide expressed on the surface membrane of HEL cells is closely related to platelet GPIb and corresponds to an incompletely or abnormally O-glycosylated GPIb alpha subunit.
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PMID:Expression of platelet glycoprotein Ib alpha in HEL cells. 346 23

The effects of the enzymes collagenase, pepsin, chondroitinase ABC and keratanase on the polypeptide composition of the mammalian tectorial membrane have been analysed using one dimensional SDS-polyacrylamide gel electrophoresis (SDS-PAGE). After reduction at least ten polypeptides can be consistently and clearly recognized in SDS gels with molecular weights relative to globular protein standards of 245, 235, 190, 165, 155, 145, 100, 93, 60-73 and 35-49 kDa. With the exception of the 60-73 and 35-49 kDa bands all these polypeptides are sensitive to digestion with bacterial collagenase. The 235, 165, 155, 145 and 93 kDa bands also resist degradation by cold, acidic pepsin. Amino acid analysis of whole tectorial membranes demonstrates that glycine accounts for nearly 25% of the total amino acid content, that proline, hydroxyproline and hydroxylysine are present and that amine sugars can be detected in fairly high concentrations. Estimates based on hydroxyproline content suggest that collagens account for 25-50% of the total tectorial membrane protein. Immunoblotting techniques demonstrate the presence of polypeptides cross reacting with antisera to Type II collagen, Type IX collagen and Type V collagen. Results from immunohistochemical studies confirm that these polypeptides are present in the tectorial membrane and are not contaminants of the isolation procedure. Collagenase treatment of tectorial membranes reveals the presence of an additional non-collagenous polypeptide with an apparent molecular weight of 173 kDa on 7.5% polyacrylamide gels, and polydisperse high molecular weight material spreading over a broad range at the top of the gels. This high molecular weight material and the 173, 60-73 and 35-49 kDa non-collagenous polypeptides are pepsin sensitive and all bind wheat germ agglutinin (WGA) suggesting that they contain N-acetyl glucosamine. The 173 kDa band also binds soybean agglutinin (SBA) suggesting the presence of N-acetyl galactosamine. In the absence of reducing agent the 173 and 60-73 kDa bands are no longer observed and high molecular weight material forming a broad band at the top of the separating gel is seen. The electrophoretic behaviour of this non-collagenous, glycosylated, disulphide bonded, high molecular weight material is altered by treatment with keratanase but not by chondroitinase ABC. The results of this study indicate the tectorial membrane contains at least three different collagen types and, in addition to these collagenous proteins, several non-collagenous, glycosylated polypeptides that may account for as much as 50% of the total tectorial membrane protein.
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PMID:Polypeptide composition of the mammalian tectorial membrane. 354 19

Pain is a complex phenomenon involving both neurophysiological and psychological components. Pathophysiological mechanisms involve neural pathways, and a variety of pain-producing substances and modulating mechanisms. These include acetylcholine, serotonin, histamine, bradykinin, prostaglandins, substance P, somatostatin, cholecystokinin, vasoactive intestinal polypeptide, noradrenaline and endogenous opioid peptides. In assessing patients with pain, it is essential to evaluate the cause of the pain, its severity, type, location, duration, quality, and response to therapies, among other factors. The measurement of pain is dependent on subjective responses, which are evaluated by methods which have been well developed over the last three decades. Alleviation of pain by non-drug treatments must be considered as well as use of pharmacological treatments. These include psychological support, placebos, relaxation training, biofeedback, hypnosis, heat, cold, physical supports and surgery. Oral drugs are generally preferable to parenteral drugs, as are drugs with few side effects and low addictive liability. Both overtreatment and undertreatment are to be avoided. Patients can be expected to differ in their needs and responses, and economic considerations ought not be ignored. Newer approaches to pain management include self-administration of parenteral drugs, the search for new types of analgesics and appreciation of the relationship between age, sex, race, etc. and the response to analgesics. Tricyclic antidepressants, phenothiazines and the new non-steroidal anti-inflammatory drugs have pointed the way to possible improvements in our ability to tailor specific drugs to the needs of individual patients.
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PMID:The management of pain. 355 78

A temperature-sensitive (ts) defect in growth of the A/Ann Arbor/6/60 (A/AA/60) cold-adapted (ca) and ts variant strain has been studied. At the restrictive temperature of 38.5 degrees C, the variant synthesized all the viral polypeptides in normal amounts within the infected cells, but the virions released into the culture fluid contained greatly reduced amounts of the matrix (M1) polypeptide and showed significantly low infectivity per unit hemagglutinin activity. Cell fractionation experiments revealed that incorporation of the M1 polypeptide into plasma membranes of the variant-infected cells was selectively reduced at 38.5 degrees C, whilst it occurred normally at 34 degrees C. The ts reassortants between the A/AA/60 variant and the A/AA/1/80 wild type (wt) strain (non-ts), which had the M gene derived from the wt parent, also showed similar patterns. These results suggest that the ts defect of the variant and its ts reassortants involves the process of incorporation of the M1 polypeptide into the plasma membranes of the infected cells and that this defect is not attributable to the M gene of the variant.
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PMID:Temperature-sensitive defect of influenza A/Ann Arbor/6/60 cold-adapted variant leads to a blockage of matrix polypeptide incorporation into the plasma membrane of the infected cells. 360 55

A comparison of mammalian gamma-crystallins has been made by computer-graphics model building of several gamma-crystallin sequences based on the atomic co-ordinates of the X-ray determined structure of calf gamma-II crystallin. The complete family of rat gamma-crystallins is compared together with the orthologous protein, gamma 1-2 crystallin, from rat, human and calf lens, and the orthologous protein, gamma 2-1 crystallin, from rat and human lens. In human gamma-crystallins, a major structural difference, the replacement of an arginine by a cysteine, occurs in one of the four-fold repeated folded hairpins, which may affect stability. Sequence variations involving buried residues were observed, leading to small differences in core packing of the different sequences which may be related to their regional location in the lens. Model-building studies also indicate that the surfaces of the different gamma-crystallins vary in number of exposed hydrophobic residues and ion pairs. These differences would affect protein-water interactions and therefore contribute to refractive index. A major variable region of the gamma-crystallin structures involves polar residues surrounding the inter-domain contact and the length of the polypeptide connecting the two domains. An attempt is made to correlate bovine gamma-crystallins which are known to be responsible for cold cataract with the corresponding sequences from rat lens.
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PMID:Structural variation in mammalian gamma-crystallins based on computer graphics analyses of human, rat and calf sequences. 1. Core packing and surface properties. 373 18


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