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)

Baseline rates for secretion of mucous glycoprotein were similar similar (680--830 microgram/g tissue/24 hour) for cultured tracheal epithelium from newborns of 26--32 weeks' gestation, full term newborns, and older children. Addition of methacholine to culture medium augmented secretory rates of glycoprotein from all tissue sources 3--5 fold. The overall composition of secreted mucous glycoproteins changed little with increasing age. A trend toward less sulfation and toward increased sialic acid and fucose content was noted in secreted glycoproteins from explants of older subjects. Histochemical observations of stored glycoprotein in tracheal tissue, which was subsequently used for organ culture experiments, confirmed that a modest, but consistent sulfate to sialic acid shift occurs during early life. In contrast, baseline secretory rates for lysozyme from tracheal epithelium of preterm infants were one-half as large as rates from epithelium of full term babies and were refractory to cholinergic stimulation. Stimulation of lysozyme secretion by a cholinergic agonist was achieved in all cases by 40 weeks' gestation. We conclude that basal glycoprotein secretion and the mechanism for glycoprotein response to cholinergic stimulation have developed by the earliest age of viability, but that lysozyme secretion is deficient and is unresponsive to cholinergic stimulation in tracheal tissue from preterm newborns.
Pediatr Res 1977 Sep
PMID:Human tracheobronchial secretions: development of mucous glycoprotein and lysozyme-secreting systems. 90 85

Cyanomethyl 1-thioglycosides ofD-galactose, D-glucose, 2-acetamido-2-deoxy-D-glucose, and D-mannose were prepared from the respective pseudothiourea derivatives and chloroacetonitrile. The nitrile group in these cyanomethyl thioglycosides can be converted to a methyl imidate group by treatment with sodium methoxide or HC1 in dry methanol to yield 2-imino-2-methoxyethyl 1-thioglycosides (IME-thioglycosides). The factors influencing the yield of IME-thioglycosides were investigated. The most convenient method of preparing IME-thioglycosides was treating 0.1 M cyanomethyl thioglycoside peracetate in dry methanol with 0.01 M sodium methoxide at room temperature for 24-48 h (50-60% yield). These IME-thioglycosides reacted readily with simple amines, amino acids, and proteins in mildly alkaline buffer solutions. Alpha-amylase and lysozyme modified with these reagents under appropriate conditions retained full activities. Thus the IME-thioglycosides constitute a new group of reagents for attaching sugars to proteins.
Biochemistry 1976 Sep 07
PMID:2-Imino-2-methoxyethyl 1-thioglycosides: new reagents for attaching sugars to proteins. 96 12

Thioglycosides of D-galactose, D-glucose, N-acetyl-D-glucosamine, and D-mannose were covalently attached to Aspergillus oryzae alpha-amylase, hen's eggs lysozyme, and bovine serum albumin by amidination, diazo coupling, and amide formation. The binding of the newly formed glycoproteins (neoglycoproteins) to rabbit liver membranes was measured, using asialoorosomucoid as a reference. Attachment of D-galactosides by any of the three methods enhanced binding by several orders of magnitude. Coupling of a comparable number of D-mannosides or N-acetyl-D-glucosaminides had little or no effect. Attachment of D-glucosides also enhanced binding but to a variable extent depending on the method of attachment. Thus, the behavior of neoglycoproteins toward rabbit liver membranes closely paralleled that of serum glycoproteins (Ashwell and Morell, 1974) with respect to sugar specificity.
Biochemistry 1976 Sep 07
PMID:Attachment of thioglycosides to proteins: enhancement of liver membrane binding. 96 13

Earlier studies of the magnetic field dependence of the nuclear spin magnetic relaxation rate of solvent protons in solutions of diamagnetic proteins have indicated that this dependence (called relaxation dispersion) is related to the rotational Brownian motion of solute proteins. In essence, the dispersion is such that 1/T1 (the proton spin-lattice relaxation rate) decreases monotonically as the magnetic field is increased from a very low value (approximately 10 Oe); the dispersion has a point of inflection at a value of magnetic field which depends on protein size, shape, concentration, temperature, and solvent composition. The value of the proton Larmor precession frequency nu(c) at the inflection field appears to relate to tau (R), the rotational relaxation time of the protein molecules. We have measured proton relaxation dispersions for solutions of various proteins that span a three-decade range of molecular weights, and for one sample of transfer ribonucleic acid. We have also measured deuteron relaxation dispersions for solutions of three proteins: lysozyme, carbonmonoxyhemoglobin, and Helix pomatia hemocyanin with molecular weight 900 000. A quantitative relationship between both proton and deuteron dispersion data and protein rotational relaxation is confirmed, and the point is made that magnetic dispersion measurements are of very general applicability for measuring the rotational relaxation rate of macromolecules in solution. It has been previously shown that the influence of proton motion on the relaxation behavior of the solvent is not due to exchange of solvent molecules between the bulk solvent and a hydration region of the protein. In the present paper, we suggest that the interaction results from a long range hydrodynamic effect fundamental to the situation of large Brownian particles in an essentially continuum fluid. The general features of the proposed mechanism are indicated, but no theoretical computations are presented.
Biochemistry 1976 Sep 21
PMID:Protein rotational relaxation as studied by solvent 1H and 2H magnetic relaxation. 96 35

Circular dichroism spectra have been obtained for albumin, alpha-chymotrypsinogen, collagen, concanavalin A, elastase, hemoglobin, histone f2b, alpha-lactalbumin, lactate dehydrogenase, beta-lactoglobulin, lysozyme, myoglobin, papain, ribonuclease A, and thermolysin in the presence of sodium dodecyl sulfate and dithiothreitol. While all spectra have the shape anticipated for a mixture of random coil and alpha helix, the intensities differ markedly ([theta]222 ranges from --1400 to --15 000 deg cm2/dmol). The variation in the circular dichroism can be quantitatively explained by a model which assumes that the arginyl, histidyl, and lysyl residues have an enhanced probability of propagating a helical segment in the presence of the detergent. The model also permits the computation of dimensional properties (unperturbed end-to-end distance and radius of gyration) for polypeptides of known amino acid sequence. Such computations have been performed for 67 proteins. The computed dimensions are compatible with experimental values and with the molecular weight dependence of the transport properties of the complexes. Furthermore, the model can account for the abnormal transport properties of the sodium dodecyl sulfate complexes formed by ribonuclease A, collagen fragments, and histones f2a1, f2a2, f2b, and f3. Even though some of the protein--sodium dodecyl sulfate complexes have helical contents as high as 50%, their overall conformation more closely approximates that of a random coil than a rod.
Biochemistry 1976 Sep 21
PMID:Conformational properties of the complexes formed by proteins and sodium dodecyl sulfate. 96 36

Lysozyme was isolated from the small intestine of mice by combined ion-exchange and molecular sieve chromatography. This lysozyme differs from that isolated from the urine of mice with monocytoma in amino acid composition, and migration rate in cellulose acetate electrophoresis. As intestinal lysozyme originates at least in part from the Paneth cell, our results point towards the existence of isozymes of lysozymes in mice.
Experientia 1976 Sep 15
PMID:Purification and partial characterization of lysozyme from mouse small intestine. 97 38

The amylase:creatinine clearance ratio in patients suffering from acute pancreatitis or acute duodenal perforation was higher than normal in both groups of patients. These findings cast doubt on the value of this parameter as a specific index of acute pancreatitis. The mechanism or mechanisms underlying the increased amylase excretion have not been determined. However, the markedly elevated urinary excretion of lysozyme observed in some patients suggests, by analogy, that diminished tubular reabsorption of amylase may contribute towards the elevated amylase:creatinine ratio.
S Afr Med J 1976 Sep 18
PMID:Amylase: creatinine clearance ratio and urinary excretion of lysozyme in acute pancreatitis and acute duodenal perforation. 98 10

The possibility of representing the conformations of a pair of peptide units in terms of two parameters, namely angle (nu) between the two peptide planes and the virtual-bond angle delta (C(alpha)i-1, C(alpha)i, C(alpha)i+1), and its usefulness in recognizing unfavourable conformations, is discussed. To exemplify the concept, the local conformations in lysozyme have been plotted in the (nu,delta) plane.
Biochem J 1976 Sep 01
PMID:A new type of representation of dipeptide conformation. 98 17

Hen blood serum (White Leghorn) possessed the lytic action against Micrococcus lysodeikticus which was less than one-thousandth of egg white obtained from hens of the same species, suggesting that lysozyme was present. The filter-sterilized hen blood serum also inhibited the growth of M. lysodeikticus in broth culture. The isolated lysozyme, purified by column chromatography and gel filtration, proved to be a basic protein with a low molecular weight (about 15,000), active against M. lysodeikticus, and more stable at acidic pH values than at alkaline pH values when heated. In amino acid composition, the isolated serum lysozyme had slightly higher proline and lower aspartic acid content than hen egg white lysozyme. The blood serum lysozyme was less heat stable at various pH values (4.5 to 8.4) than egg white lysozyme.
Poult Sci 1976 Sep
PMID:Lysozyme in hen blood serum. 99 2

The antibacterial effect of lysozyme manufactured in the USSR was studied with respect to 1496 pathogenic strains of different microbial species. It was found that the percentage of the organisms sensitive to lysozyme among the total number of the microbes tested was not high and ranged within 1.5-3 except streptococci (21.7 per cent). Significant differences in the minimum bacteriostatic concentration (from 0.0006 to 10 mg/ml) with respect to both different microbial species and organisms belonging to the same microbial species were found. By the level of the antibacterial activity the Soviet lysozyme was not inferior to the Italian preparation. With respect to streptococci the Soviet lysozyme was more active.
Antibiotiki 1976 Sep
PMID:[Characteristics of the antimicrobial activity of lysozyme]. 99 64


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