Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Elimination of low molecular weight proteins during sequential ultrafiltration/dialysis was studied in 29 uremic patients. Beta-2-microglobulin, retinol binding protein, free light chains lambda and kappa, Zn-alpha-2-glycoprotein, hemopexin, prealbumin, hemoglobin, albumin, acid alpha-1-glycoprotein, haptoglobin, alpha-1-antichymotrypsin, ribonuclease, lysozyme, amylase, non-specific esterase, and proteolytic activity were detected in all ultrafiltrates tested. The level of total protein and ribonuclease was determined in 36 crude ultrafiltrates from 23 patients. Concentrated ultrafiltrates were used to quantitate retinol binding protein, prealbumin, albumin, lysozyme, and amylase. Other proteins identified in the ultrafiltrates are present in trace amounts. The question was discussed whether ++inextensive but systematic loss of proteins during hemofiltration in chronic RDT might be the cause of patient homeostasis disturbances.
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PMID:Detection of plasma proteins during sequential ultrafiltration/dialysis. 406 85

A method has been developed for measuring the adhesion of platelets to purified collagen fibers obtained from bovine tendon. This method differs from others in that: (a) platelet adhesion is measured in the absence of platelet aggregation; (b) platelet-rich plasma collected in ACD (acid citrate dextrose) or EDTA, or washed platelets can be employed; (c) adherent platelets are enumerated directly; (d) erythrocytes and leukocytes do not adhere. Washed platelets suspended in human Ringer solution exhibit negligible adhesion (at the platelet concentrations employed) in contrast to washed platelets suspended in plasma. Addition of purified human fibrinogen (95% clottable, 2-4 mg/ml) to human Ringer solution completely restores the ability of washed platelets to adhere to collagen fibers. Albumin (fatty acid free, 50 mg/ml) is also capable of restoring adhesion. Albumin and seven other proteins at concentrations of 5-10 mg/ml, with varying molecular weights, isoelectric points, and frictional coefficients are incapable of supporting the adhesion of washed platelets. The proteins tested were human globulin, hexokinase, hemoglobin, cytochrome-C, insulin, thyroglobulin, and muramidase. Platelet adhesion is proportional to both platelet concentration and fibrinogen concentration, but is independent of temperature or glycogen stores. Modification of fibrinogen by acylation of amino groups or removal of sialic acid has no effect on its ability to support platelet adhesion. Degradation of fibrinogen with purified plasmin results in decreased support of platelet adhesion. This accompanied formation of early breakdown products with clottability ranging from 84-0%. Formation of fibrinogen degradation products was monitored by SDS-polyacrylamide gel electrophoresis of the corresponding fibrins after reduction of disulfide bonds (a method capable of distinguishing alpha-, beta- and gamma-chains). Decreased support of platelet adhesion is associated with the disappearance of intact alpha- chains and early modification of the beta-chains. Purified proteinpolysaccharide macromolecules obtained from bovine nasal and humeral cartilage, and from nucleosus pulposus are as effective as fibrinogen on a weight basis and ten to thirty times more effective on a molar basis in supporting platelet adhesion. The purified mucopolysaccharide side chains: chondroitin-4-sulfate, chondroitin-6-sulfate, and keratan-sulfate are incapable of supporting platelet adhesion.
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PMID:Biochemical and biophysical aspects of human platelet adhesion to collagen fibers. 556 92

On the basis of the known sequences and structures of myoglobin, and alpha and beta hemoglobin, a possible correlation between certain amino acids in the sequence and the location of the helical and non-helical parts of the structure is suggested. The presence in the sequence of four critical groups; proline, aspartic acid, glutamic acid, or histidine appears to be necessary (although the last three are not sufficient) for a helical disruption to form. Additional support for this correlation is obtained from analyses of proline replacement in mutant and variant proteins. A mechanism based on hydrophobic bonding is proposed as a rationale for the apparent behavior of these groups. On the basis of these rules and correlations, secondary structures can be proposed for lysozyme and tobacco mosaic virus protein which are consistent with several pieces of evidence.
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PMID:The influence of amino-acid sequence on protein structure. 588 9

The proteinase of a Trichosporon species was partially purified by dialysis, ammonium sulfate fractionation, and Sephadex G-100 gel filtration. A 170-fold purification of the enzyme with a 1.4% recovery of the activity was achieved. The proteinase was separated into a major component and possibly two minor components by starch gel electrophoresis. The pH optimum of the enzyme was 5.8 to 6.2. It was active against casein, hemoglobin, and crab protein substrates, but inactive against bovine serum albumin, lysozyme, and benzoylarginine ethyl ester. It was slightly activated by 10 mm cysteine, 0.1 mm ethylenediaminetetraacetic acid, and 0.1 mm Co(++). There was slight inhibition by 10 mm Co(++) and 0.1 mm phenylmethylsulfonylfluoride, and total inhibition by 1 mmp-chloromercuribenzoate. The proteinase was completely inactivated by heating at 60 C for 10 min.
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PMID:Characteristics of a proteinase of a trichosporon species isolated from Dungeness crab meat. 591 89

The three-dimensional structures of alpha-helices can be represented by two-dimensional projections which we call helical wheels. Initially, the wheels were employed as graphical restatements of the known structures determined by Kendrew, Perutz, Watson, and their colleagues at the University of Cambridge and by Phillips and his coworkers at The Royal Institution. The characteristics of the helices, discussed by Perutz et al. (1965), and Blake et al. (1965), can be readily visualized by examination of these wheels. For example, the projections for most helical segments of myoglobin, hemoglobin, and lysozyme have distinctive hydrophobic arcs. Moreover, the hydrophobic residues tend to be clustered in the n +/- 3, n, n +/- 4 positions of adjacent helical turns. Such hydrophobic arcs are not observed when the sequences of nonhelical segments are plotted on the wheels. Since the features of these projections are also distinctive, however, the wheels can be used to divide sequences into segments with either helical or nonhelical potential. The sequences of insulin, cytochrome c, ribonuclease A, chymotrypsinogen A, tobacco mosaic virus protein, and human growth hormone were chosen for application of the wheels for this purpose.
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PMID:Use of helical wheels to represent the structures of proteins and to identify segments with helical potential. 604 67

Recently, we reported the synthesis and immunochemistry of two peptides designed, by complementarity and surface-simulation synthesis, to mimic antibody-combining sites against two antigenic sites of lysozyme. In the present work antibodies were raised against one of these peptides, which is complementary to antigenic site 3 of lysozyme, to determine whether these antibodies will react with anti-lysozyme antibodies. Radioiodinated antipeptide antibodies were bound by immunoadsorbents of the immune IgG from two goats anti-lysozyme antisera but not by adsorbents of myoglobin, non-immune goat IgG or immune IgG of antisera against cytochrome c. The binding of anti-peptide antibodies to adsorbents of anti-lysozyme antibodies was fully inhibited by free lysozyme but not by bovine serum albumin, human hemoglobin A, horse cytochrome c or bovine ribonuclease A. Thus, antisera against an antibody-combining site can be raised by immunizing with a peptide which probably does not exist in the antibody but is designed by surface-simulation synthesis to mimic an antibody-combining site.
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PMID:Antibodies to synthetic antibody-combining sites. Antibodies against a surface-simulation peptide with antibody-combining activity toward lysozyme antigenic site 3 react with lysozyme antibodies. 615 39

The bone marrow biopsy specimens of 35 patients with benign and malignant erythroid hyperplasias were examined for the presence of hemoglobin A, hemoglobin F, muramidase (lysozyme), and transferrin, using an indirect immunoperoxidase method (PAP) on Zenker's-fixed paraffin-embedded bone marrow biopsy specimens and particles. Five cases of each of the following entities were studied: erythroleukemia and erythremic myelosis, acute granulocytic leukemia with maturation (FAB M2), polycythemia rubra vera, myeloproliferative syndrome in childhood, megaloblastic anemia (B12 and folate deficiency), erythroid hyperplasia (regenerating bone marrow and hemolytic anemia), and Ph' chromosome positive chronic granulocytic leukemia. Hemoglobin A was present in both the early and late erythroid precursors in all conditions. Hemoglobin F was the predominant hemoglobin in early erythroblasts of pernicious anemia and in both early and late erythroid elements in erythroleukemia and erythremic myelosis. Small quantities of hemoglobin F were present in a few isolated clusters in other conditions. Staining for hemoglobin F may be useful in identifying immature erythroid precursors and in distinguishing some cases of dysplastic erythroid hyperplasia from neoplasia. Additionally, these findings suggest that the maturational switch in hemoglobin synthesis operates with distinct pathways under different conditions.
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PMID:An immunohistochemical study of hemoglobin A, hemoglobin F, muramidase, and transferrin in erythroid hyperplasia and neoplasia. 619 99

The components of the nitrogenase complex, MoFe-protein and FeMo-cofactor, possessing no ATPase or nitrogen-fixing activity, maintain the 18O-exchange at the level of 1 atom of 18O per molecule of Pi, which is inhibited by ATP. The Fe-protein complex does not catalyze the 18O-exchange. The nitrogenase components do not hydrolyze the substrates for phosphatase (p-nitrophenylphosphate, beta-glycerophosphate, glucose 1-phosphate and ribose 5-phosphate). The artificial albumin-containing MoFe- and Fe-proteins and the carboxyl group-containing proteins (albumin, hemoglobin, lysozyme) as well as sodium molibdate do not catalyze the 18O-exchange. It is assumed that the site of the ATPase center which is subjected to phosphorylation, is located on the MoFe-protein.
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PMID:[Localization of the ATPase site of nitrogenase by isotopic oxygen exchange [180]-Pi in equilibrium with H20]. 621 20

A method for studying protein structure and estimating its electron conducting properties is proposed. The method is based on the kinetic recording of exchange quenching triplet labels and probes phosphorescence by chromophores or paramagnetic centres. It is shown that different types of exchange interactions (spin exchange, exchange energy transfer) between centres with distance R are described approximately by an equation (I = I0 exp-2R/L) where L changes from 0.7 A (absence of electron coupling--system of type I) to 6.5 A (strong electron coupling--system of type II). I (sec-1) corresponds to exchange energy transfer rate constant or exchange integral in the case of spin exchange. Life-times of excited triplet state eosin-isotiocionate labels connected with the terminal NH2-groups of the following preparations were measured by the method of kinetic phosphorescence decay recording: human oxyhemoglobin, methemoglobin, F- and CN-methemoglobin, metmyoglobin, F- and CN-metmyoglobins. The influence of lysozyme of the nitroxyl spin label bound to His-15 group on the phosphorescence spectrum was investigated. The analysis of our and literature data on the exchange interactions between the centres localized on the protein with known structure (hemoglobin, myoglobin, lysozyme, carboangidrase, bacterial ferredoxin) permit us to conclude that in the examined cases the experimental values correspond to model systems of type I and are different from the dependence in systems of type II by 5--15 order. This allows us to use equation (I) for estimation of the distances between the centres on proteins.
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PMID:[Use of triplet state exchange disactivation phenomenon for the study of structure and electron conductivity of proteins]. 626 83

The fluorescence polarization of fluorescent derivatives of hemoglobin and myoglobin was measured as a function of the concentration of added polymers (PEG-6 000, PEG-20 000) and globular proteins (lysozyme, ribonuclease A, beta-lactoglobulin). The results indicated that the effective size and shape of 1-anilino-9-naphthalene sulfonate myoglobin are unaltered in the presence of up to 25 g/dl poly(ethylene glycol), whereas they are significantly altered in the presence of comparable concentrations of other proteins. The results are consistent with the hypothesis that in the presence of high concentrations of added protein, 1-anilino-9-naphthalene sulfonate myoglobin self-associates to form a dimer similar in size and shape to 1-anilino-9-naphthalene sulfonate hemoglobin.
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PMID:Evidence for protein self-association induced by excluded volume. Myoglobin in the presence of globular proteins. 627 Dec 44


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