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)

The phenotypes of 273 offspring of 56 matings of various genotypes of lysozyme-deficient and normal New Zealand white rabbits were analyzed. It was determined that lysozyme deficiency of rabbits is inherited as an autosomal recessive with complete penetrance. The symbol ld is suggested for the gene for lysozyme deficiency. Further studies on the nature of the condition revealed that the lysozyme deficiency was not due to a lysozyme that was cold labile, or to a lysozyme that was so tightly bound it was unavailable for enzymatic assay, or to a lysozyme with a variant pH optimum. It was demonstrated, however, that the pH profile of the lysozyme remaining in the ld/ld rabbits was different from that found in normal rabbits.
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PMID:Inheritance of lysozyme deficiency in rabbits. 3 55

Strains of Escherichia coli can inhibit the in vitro growth of Neisseria gonorrhoeae. One E. coli strain released a potent agar-diffusible gonococcal growth inhibitor which was extracted and assayed in an agar well assay system. The culture conditions necessary to produce the inhibitor were determined. The inhibitor was bacteriostatic, in most cases, for N. gonorrhoeae. Based on ultrafiltration and column chromatography, the inhibitor appeared to have a molecular weight in the range of 1200 to 2000. Evidence that the molecule contained charged sites was obtained by membrane binding and column chromatography. The inhibitor was stable to extremes of heat, cold and pH. It was not volatile or susceptible to proteolytic enzymes, lysozyme, lipase, DNAase, RNAase or certain chelating agents. Its activity was completely blocked by ferric ammonium citrate. This inhibitor is dissimilar to previously reported gonococcal inhibitors of bacterial origin.
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PMID:Properties of a gonococcal inhibitor produced by Escherichia coli. 4 57

The distribution of ribonucleoprotein (RNP) within the mitotic spindle of newt lung epithelial cells was studied with the high voltage electron microscope (HVEM) using Bernhard's uranyl-EDTA-lead staining of thick sections in conjunction with the ribonuclease digestion of fixed cells. The results indicate that aside from ribosomes, the major RNP-containing components of the spindle are the kinetochores and centrioles, both of which stain electron-opaque after EDTA treatment. In both cases, the electron-opaque material associated with these microtubule organizing centers (MTOC's) can be removed by RNAse digestion and cold perchloric acid (PCA) extraction under conditions which leave the spindle microtubules (Mts) centrioles, and kinetochores intact. The staining reaction is not abolished by cold PCA extraction alone or by substituting other positively charged proteins (i.e., cytochrome c or lysozyme) for RNAse. The RNP component of the kinetochore is closely associated with the bases of the kinetochore microtubules. The RNP component of the centriole can be seen to surround the microtubules of the triplet blades. No evidence was found to indicate the presence of RNP in the pericentriolar material. The possible function of both kinetochore and centriolar RNP is discussed.
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PMID:Ribonucleoprotein staining of centrioles and kinetochores in newt lung cell spindles. 8 14

Stable and metabolically active protoplasts were prepared from the unicellular cyanophyte, Anacystis nidulans, by enzymatic digestion of the cell wall with 0.1% lysozyme. The yield of protoplasts from intact algal cells was approx. 50%. Incorporation of L-[U-14C]leucine into cold trichloroacetic acid-insoluble material from protoplasts preparations was linear for 1.5 h and continued for an additional 2.5 h. Incorporation of radiolabeled leucine into hot trichloroacetic acid-insoluble material from protoplast preparations demonstrated protein synthesis in protoplasts in vitro. Phycocyanin is the principal phycobiliprotein and allophycocyanin is a minor phycobiliprotein in A. nidulans cells. The light-absorbing chromophore of both of these phycobiliproteins is the linear tetrapyrrole (bile pigment), phycocyanobilin. Radiolabeled phycocyanin and allophycocyanin were isolated from protoplast preparations which had been incubated with L-[U-14]leucine or delta-amino[4-14C] levulinic acid (a precursor of phycocyanobilin). The radio-labeled phycobiliproteins were purified by ammonium sulfate fractionation and ion-exchange chromatography on brushite columns. The specific radioactivity of phycocyanin and allophycocyanin in brushite column eluates (protoplasts incubated with radiolabeled leucine) was 106 000 and 82 000 dpm/mg, respectively. The specific radioactivity of phycocyanin and allophycocyanin in brushite column eluates (protoplasts incubated with radiolabeled delta-aminolevulinic acid) was 33 000 and 38 000 dpm/mg, respectively. Phycobiliproteins from protoplasts incubated with radiolabeled leucine were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 25% of the incorporated radioactivity in protoplast lysates and approx. 60% of the incorporated radioactivity in protoplast lysates and approx. 60% of the incorporated ratioactivity in phycocyanin and allophycocyanin (in brushite column eluates) comigrated with the subunits of these phycobiliproteins on sodium dodecyl sulfate-polyacrylamide gels. Chromic acid degradation of phycobiliproteins from protoplast preparations incubated with delta-amino[4-14C] levulinic acid yielded radiolabeled imides which were derived from the phycocyanobilin chromophore. Imides from radiolabeled phycobiliproteins isolated from protoplast preparations incubated with L-[U-14C]leucine did not contain radioactivity. These results show that both the apoprotein and tetrapyrrolic moieties of phycocyanin and allophycocyanin were synthesized in A. nidulans protoplasts in vitro.
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PMID:Phycobiliprotein synthesis in protoplasts of the unicellular cyanophyte, Anacystis nidulans. 9 57

Cold centrifugation of lysis-inhibited Escherichia coli B infected with wild-type T4D results in extensive lysis beginning around 20 min after infection at 37 degrees C. Infection with an e mutant, which fails to make lysozyme, prevents lysis, but does not prevent a marked loss of K+ and Mg3+. The t gene product, thought to disrupt the cytoplasmic membrane in natural lysis, is not required for this handling-induced cation loss or lysis. Three lines of evidence argue that late protein synthesis is required to develop this potential for cation loss; the potential does not develop in infections by: (i) mutants defective in DNA synthesis, (ii) mutants defective in gene 55, and (iii) wild-type T4 when chloramphenicol is added at 6 min after infection. All late mutants examined, which are blocked in the major pathways of morphogenesis, do not prevent development of the potential. The evidence argues for a new, late effect of T4 infection on the cytoplasmic membrane.
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PMID:Late effect of bacteriophage T4D on the permeability barrier of Escherichia coli. 34 25

Minicells produced by Bacillus subtilis CU403 (divIVB1) are capable of mucopeptide biosynthesis as shown by the incorporation of L-alanine, D-alanine, and N-acetylglucosamine into trichloroacetic acid-precipitable material, which can be degraded to trichloroacetic acid-soluble material by lysozyme digestion. Incorporation of the precursors is sensitive to vancomycin and D-cycloserine and insensitive to chloramphenicol. Penicillin inhibits the incorporation of D- and L-alanine N-acetylglucosamine at concentrations in excess of 10 mug of penicillin per ml; however, minicells are insensitive to penicillin-induced lysis. The material synthesized in minicells from N-acetylglucosamine is not subject to turnover during a subsequent 6-h incubation period. [2-3H]glycerol is converted to a cold trichloroacetic acid-precipitable form by minicells. This synthesis is not inhibited by vancomycin, penicillin, D-cycloserine, or chloramphenicol. Fractionation of the material synthesized from glycerol into hot trichloroacetic acid-soluble material and chloroform/methanol-extractable material indicates that minicells convert glycerol into teichoic acid and lipid.
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PMID:Synthesis of cell envelope components by anucleate cells (minicells) of Bacillus subtilis. 40 71

The effects on the stringent control of ribosomal ribonculeic acid synthesis of the removal of cell wall, cold-shock treatment of cells, LiCl treatment of toluene-treated cells, and hypotonic treatment of spheroplasts were examined using Escherichia coli rel+ cells. Neither the removal of cell wall with penicillin or lysozyme nor the cold-shock treatment of the cells had an effect on the stringent control. The control mechanism, however, disappeared after the LiCl treatment of the toluene-treated cells, with the release of some protein component(s), possibly from the cytoplasmic membrane. The hypotonic and other treatments of spheroplasts, which disrupt the cytoplasmic membrane, also led to the abolishment of the control mechanism. These results suggested that the operation of the stringent control of ribosomal ribonucleic acid synthesis requires the cytoplasmic membrane, in which some proteins labile with LiCl treatment are embedded.
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PMID:Regulation of ribonucleic acid synthesis in spheroplasts, cold-shocked cells, and toluene-treated cells of Escherichia coli. 78 28

A remarkable resemblance between the appearance of opacity in lysozyme--salt water mixtures and the development of opacity in cold cataract in the young rat lens is strong evidence that cold cataract is fundamentally a phase separation of the "protein-water binary mixture" in the lens.
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PMID:Phase separation of a protein-water mixture in cold cataract in the young rat lens. 88 36

In order to broaden the scope and increase the utility of differential scanning calorimetry, a theoretical model of calorimetric thermograms is presently proposed which facilitates their biophysical interpretation and accounts explicitly for their modifications induced by denaturing agents and/or pH. The model rests mainly on statistical-physical considerations, the denaturation-linked increase of the number of binding sites for denaturants (including H+) serving as the conceptual basis for thermogram modelling. Denaturants were envisioned as contributing indirectly to thermal denaturation by forming complexes preferentially with unfolded protein molecules, shifting thus the equilibrium towards the denatured phase. After postulating the probability of complex formation, mean numbers of the relevant molecular species were computed by ensemble averaging. Finally, an eight-parameter expression has been derived defining protein heat capacity as a function of both temperature and denaturant concentration (or pH), each of the eight parameters having a distinct biophysical meaning. The model has been tested by applying it to the prediction of the pH-dependence of thermograms. Four proteins have been considered (lysozyme, myoglobin, apomyoglobin, and ribonuclease A), each represented by a series of three to four published thermograms recorded under different pH conditions. Model equations, fitted simultaneously to all thermograms in a pH series, reproduced correctly experimental tracings. Parameter values obtained as best-fit requirements (particularly those representing the number of binding sites unmasked by denaturation and the free energy of ion binding) were in close agreement with empirical, mainly potentiometric, data from literature. The empirically established pH-independence of the total enthalpy of denaturation, the phenomenon of cold denaturation, the pH-dependence of the Gibbs free energy of denaturation, of the melting temperature and of the temperature of cold denaturation, were all correctly predicted by the model. Combined effects of multiple denaturants, including the effects of pH in the presence of denaturants other than protons, are also predictable by the model.
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PMID:Biophysical models of protein denaturation. II. Effects of denaturants and of pH. 166 34

The method given earlier for predicting the thermodynamics of protein unfolding from the x-ray structure of a protein is applied here to the poly(L-alanine) helix. First, the fitting parameters derived earlier from a data base of 10 proteins were used to predict the unfolding thermodynamics of 4 other proteins. The agreement between the observed and predicted values is comparable to that found for the 10 proteins studied initially. Next, the temperature dependences of the Gibbs energy and enthalpy changes for unfolding of bacteriophage T4 lysozyme were predicted and compared with data in the literature. The predicted and observed temperature dependences are similar and the predicted results indicate that cold denaturation should be observed at low temperatures, as observed recently for a T4 lysozyme mutant. The fitting parameters derived from thermodynamic data for protein unfolding and for hydration of model compounds were used to predict the unfolding thermodynamics of the poly(L-alanine) helix. The results predict that helix formation is enthalpy-driven, and the predicted enthalpy change for unfolding (0.86 kcal per mol per residue) is close to the value found in a recent calorimetric study of a 50-residue alanine-rich helix.
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PMID:Prediction of the thermodynamics of protein unfolding: the helix-coil transition of poly(L-alanine). 201 95


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