Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Earlier, three genes Ds1, Ds2, and Ds3 encoding corresponding destabilase-lysozyme isoforms were identified. However only one form of the enzyme encoded by Ds3 gene coincided with the protein CNBr fragments [Mol. Gen. Genet. 253 (1996) 20]. In this work we found by ESI-TOF mass spectrometry that the enzyme preparation consists of at least three forms with molecular masses of 12677.6, 12839.7, and 12938.2Da, each of which contains seven disulfide bridges. Only one mass (12839.7Da) fits to the calculated mass for the protein encoded by Ds3 gene. Further analysis of the CNBr fragments of the enzyme showed the heterogeneity of large 5.5 kDa peptide at positions 64 (threonine or arginine) and 67 (histidine or arginine) in the wild-type amino acid sequence. One CNBr peptide, with Arg and His at positions 64 and 67, respectively, correlates in the molecular mass with the protein encoded by Ds3. In addition, we have found a new acid form of destabilase-lysozyme, P-Ac, which differs from all known destabilase-lysozyme structures by its N-terminal amino acid sequence.
...
PMID:Multiple forms of medicinal leech destabilase-lysozyme. 1278 7

Gastric carcinoma is the fourth most common cause of cancer death worldwide but its molecular biology is poorly understood. We catalogued the genes expressed in two gastric adenocarcinomas and normal stomach, using serial analysis of gene expression (SAGE), and compared the profiles on-line with other glandular epithelia. Candidates were validated by Northern blotting and immunohistochemistry. A total of 29 480 transcripts, derived from 10 866 genes, were identified. In all, 1% of the genes were differentially expressed (>/=fivefold difference plus P-value </=0.01) between cancers and normal stomach. The most abundant transcripts included ribosomal and mitochondrial proteins, of which most were upregulated in the tumours, as were other widely expressed genes including transcription factors, signalling molecules (serine/threonine protein kinases), thymosin beta 10 and collagenase I. Transcripts abundant in normal stomach were functionally important, including gastrin, immunoglobulin alpha, lysozyme, MUC5, pS2 and pepsinogens, which were among 55 gastric-specific genes. Many transcripts were minimally characterized or new, some cancer-associated genes reflected their intestinal morphology, and some normal gastric genes had previously been considered as pancreatic carcinoma markers. The gastric carcinoma profiles resembled other tumours', supporting the existence of common cancer-associated targets. These data provide a catalogue from which to develop markers for better diagnosis and therapy of gastric carcinoma.
...
PMID:Profiling, comparison and validation of gene expression in gastric carcinoma and normal stomach. 1283 51

Atomic solvation parameters (ASPs) are widely used to estimate the solvation contribution to the thermodynamic stability of proteins as well as the free energy of association for protein-ligand complexes. In view of discrepancies in the results of free energies of solvation of folding for various proteins obtained using different atomic solvation parameter sets, systematic studies have been carried out for the calculation of accessible surface area and the changes in free energy of solvation of folding (deltaG(s,f)) for mutants of lysozyme T4 where threonine 157 is replaced by amino acids: cysteine, aspartate, glutamate, phenylalanine, glycine, histidine, isoleucine, leucine, asparagine, arginine, serine and valine. The deviations of the calculated results from the experimental results are discussed to highlight the discrepancies in the atomic solvation parameter sets and possible reasons for them. The results are also discussed to throw light on the effect of chain free energy and hydrogen bonding on the stability of mutants. The octanol to water-based ASP sets 'Sch1' and 'EM' perform better than the vacuum to water-based ASP sets. The vacuum to water-based ASP sets 'Sch3' and 'WE' can be used to predict the stability of mutants if a proper method to calculate the hydrogen bond contribution to overall stability is in place.
...
PMID:Theoretical studies on solvation contribution to the thermodynamic stability of mutants of lysozyme T4. 1287 74

Shockman, Gerald D. (Temple University School of Medicine, Philadelphia, Pa.), Joseph J. Kolb, Bohdan Bakay, Margaret J. Conover, and Gerrit Toennies. Protoplast membrane of Streptococcus faecalis. J. Bacteriol. 85:168-176. 1963.-The membrane fraction of Streptococcus faecalis (ATCC 9790) was isolated and purified, by a variety of procedures, from cultures that were grown under closely controlled conditions of physiological age and nutrition. The most satisfactory method required the use of lysozyme-to-cell ratios below 0.01 and the intermediate formation of protoplasts in osmotically protective media. Amino acid analyses of three of the membrane preparations indicated a characteristic and constant, but not unusual, pattern; 42% of the membranes from threonine-depleted and 49 to 55% of the membranes from log-phase cultures were accounted for as protein. Significant quantities of d-alanine or d-aspartic acid were not detected, indicating the absence of contaminating cell-wall substance. Essentially, all of the nitrogen was accounted for as amino acids. The lipid content of membranes from stationary-phase threonine-depleted (36%) and valine-depleted (40%) cultures was significantly higher than the corresponding fraction of exponential-phase cultures (28%). The phosphorus content of the membrane lipid was relatively constant (2.8 to 3.0%), and the nitrogen content was extremely low (0.12 to 0.26%). Thus, changes in the composition of the membrane fraction occurred during the transition of log-phase cells into threonine- or valine-depleted cells.
...
PMID:Protoplast membrane of Streptococcus faecalis. 1398 37

Various mutant lysozymes having the N-glycosylation signal sequence, R21T (Asn(19)-Tyr(20)-Thr(21)), G49N (Asn(49)- Ser(50)-Thr(51)), R21T/G49N (Asn(19)-Tyr(20)-Thr(21)/Asn(49)-Ser(50)-Thr(51)), were secreted in the Pichia pastoris expression system. The secreted amounts of these mutant glycosylated lysozymes were almost the same as those of wild-type lysozyme (about 30 mg/liter). Glycosylation of the mutant lysozymes was confirmed by SDS-PAGE patterns, Endo-H treatment, TOF-MS analysis and chemical analysis. The composition of the carbohydrate chain attached to the single glycosylated lysozymes, R21T and G49N, was GlcNAc(2)Man(9-11), while that of the double glycosylated lysozyme, R21T/G49N, was GlcNAc(4)Man(27-32). The results of a CD analysis and lytic activity suggested that the conformation of the single glycosylated lysozymes had been conserved, while that of the double glycosylated lysozyme was less stable. The emulsifying properties of the lysozyme when glycosylated were greatly improved, being especially noteworthy in the double glycosylated lysozyme.
...
PMID:Functional properties of glycosylated lysozyme secreted in Pichia pastoris. 1464 91

To design artificial proteases that cleave peptide backbones of a wide range of proteins at selected sites, artificial active sites comprising the Cu(II) complex of cyclen (Cu(II)Cyc) and aldehyde group were synthesized on a cross-linked polystyrene. The aldehyde group was employed as the binding site in view of its ability of reversible formation of imine bonds with epsilon-amino groups of Lys residues exposed on the surface of proteins and Cu(II)Cyc as the catalytic group for peptide hydrolysis. The two polymeric artificial metalloproteases synthesized in the present study cleaved all of the protein substrates examined (myoglobin, gamma-globulin, bovine serum albumin, human serum albumin, lysozyme, and ovalbumin), manifesting saturation kinetic behavior. At 50 degrees C and pH 9.0 or 9.5, K(m) was (1.3-22) x 10(-)(4) M, comparable to those of natural proteases, and k(cat) was (6.0-25) x 10(-)(4) s(-)(1), corresponding to half-lives of 4.6-19 min. Intermediacy of the imine complexes formed between the aldehyde group of the catalyst and the epsilon-amino groups of Lys residues of the substrates was confirmed by the trapping experiment with NaB(OAc)(3)H. MALDI-TOF MS of the proteolytic reaction mixtures revealed formation of various cleavage products. Structures of some of the cleavage products were determined by using carboxypeptidase A and trypsin. Among various cleavage sites thus identified, Gln(91)-Ser(92) and Ala(94)-Thr(95) were the major initial cleavage sites in the degradation of myoglobin by the two catalysts. The selective cleavage of Gln(91)-Ser(92) and Ala(94)-Thr(95) was attributed to general acid assistance in peptide cleavage by Tyr(146) located in proximity to the two peptide bonds. Broad substrate selectivity, high cleavage-site selectivity, and high proteolytic rate are achieved, therefore, by positioning the aldehyde group in proximity to Cu(II)Cyc attached to a cross-linked polystyrene.
...
PMID:Artificial metalloprotease with active site comprising aldehyde group and Cu(II)cyclen complex. 1598 87

Entamoeba histolytica is a protozoan parasite that causes colitis and liver abscesses. Several Entamoeba species and strains with differing levels of virulence have been identified. E. histolytica HM-1:IMSS is a virulent strain, E. histolytica Rahman is a nonvirulent strain, and Entamoeba dispar is a nonvirulent species. We used an E. histolytica DNA microarray consisting of 2,110 genes to assess the transcriptional differences between these species/strains with the goal of identifying genes whose expression correlated with a virulence phenotype. We found 415 genes expressed at lower levels in E. dispar and 32 genes with lower expression in E. histolytica Rahman than in E. histolytica HM-1:IMSS. Overall, 29 genes had decreased expression in both the nonvirulent species/strains than the virulent E. histolytica HM-1:IMSS. Interestingly, a number of genes with potential roles in stress response and virulence had decreased expression in either one or both nonvirulent Entamoeba species/strains. These included genes encoding Fe hydrogenase (9.m00419), peroxiredoxin (176.m00112), type A flavoprotein (6.m00467), lysozyme (6.m00454), sphingomyelinase C (29.m00231), and a hypothetical protein with homology to both a Plasmodium sporozoite threonine-asparagine-rich protein (STARP) and a streptococcal hemagglutinin (238.m00054). The function of these genes in Entamoeba and their specific roles in parasite virulence need to be determined. We also found that a number of the non-long-terminal-repeat retrotransposons (EhLINEs and EhSINEs), which have been shown to modulate gene expression and genomic evolution, had lower expression in the nonvirulent species/strains than in E. histolytica HM-1:IMSS. Our results, identifying expression profiles and patterns indicative of a virulence phenotype, may be useful in characterizing the transcriptional framework of virulence.
...
PMID:Identification of differentially expressed genes in virulent and nonvirulent Entamoeba species: potential implications for amebic pathogenesis. 1636 89

Shockman, Gerald D. (Temple University, Philadelphia, Pa.), J. Stuart Thompson, and Margaret J. Conover. Replacement of lysine by hydroxylysine and its effects on cell lysis in Streptococcus faecalis. J. Bacteriol. 90:575-588. 1965.-Hydroxylysine was not significantly incorporated by Streptococcus faecalis ATCC 9790 or 8043 until exponential growth ceased as a result of lysine exhaustion. Uptake was then rapid and virtually complete within 1 hr. Lysine absence, rather than physiological age, seemed to be the governing factor. Hydroxylysine uptake rapidly reached a peak in the acid-soluble fraction, suggesting a precursor role for substances in this fraction. Substitution of hydroxylysine for lysine was much more efficient in mucopeptide synthesis than in protein synthesis. In wall medium, less than 1% of the incorporated hydroxylysine was found in the protein fraction. Addition of lysine to both growth and wall media inhibited both further hydroxylysine uptake and transfer of hydroxylysine from acid-soluble to mucopeptide or protein fractions. Hydroxylysine resulted in decreased penicillin susceptibility only after it was postexponentially incorporated. This effect was physiologically similar to that seen after threonine deprivation or chloramphenicol treatment. Hydroxylysine incorporation increased resistance to autolysis, but failed to decrease lysozyme susceptibility when measured after heat inactivation of autolysis. Electron microscopy of negatively stained cells showed increased thickness of cell walls containing hydroxylysine. Thus, most of the effects of replacement of lysine by hydroxylysine resemble those seen after deprivation of a nonwall amino acid (e.g., threonine or valine) or after chloramphenicol treatment. Each of these conditions results in inhibition of protein synthesis while permitting cell-wall synthesis to continue, resulting in autolysis-resistant, thick-walled cells.
...
PMID:Replacement of Lysine by Hydroxylysine and Its Effects on Cell Lysis in Streptococcus faecalis. 1656 51

Previously reported techniques for the electrotransfer of foreign DNA into pediococci yield only a small number of transformants/mug DNA, especially when using undomesticated strains. This study reports an improved protocol for the electrotransformation of pediococci, based on trials using Pediococcus acidilactici P60 and the plasmid pRS4C1. The improved protocol yields from 2 to 3 log units more transformants than the previously reported methods, with up to (9.1+/-1.3)x10(4) transformants/mug of foreign DNA under the best conditions identified. The most important modifications proposed are an increase in electric field strength during electroporation (from 12.5 to 20kV/cm) and a reduction in lysozyme concentration during the preparation of electrocompetent cells (from 4000 to 2000U/ml): together, these two modifications greatly improve transformant yield. In addition, increasing cell culture time (from OD(600nm)=0.6 to OD(600nm)=1.0-1.2) and increasing dl-threonine concentration in the growth medium (from 20 to 40mM) also contribute to improved electrotransformation efficiency.
...
PMID:Optimization of technical conditions for the transformation of Pediococcus acidilactici P60 by electroporation. 1727 85

High-resolution solid-state NMR (SSNMR) of paramagnetic systems has been largely unexplored because of various technical difficulties due to large hyperfine shifts, which have limited the success of previous studies through depressed sensitivity/resolution and lack of suitable assignment methods. Our group recently introduced an approach using "very fast" magic angle spinning (VFMAS) for SSNMR of paramagnetic systems, which opened an avenue toward routine analyses of small paramagnetic systems by (13)C and (1)H SSNMR [Y. Ishii et al., J. Am. Chem. Soc. 125, 3438 (2003); N. P. Wickramasinghe et al., ibid. 127, 5796 (2005)]. In this review, we discuss our recent progress in establishing this approach, which offers solutions to a series of problems associated with large hyperfine shifts. First, we demonstrate that MAS at a spinning speed of 20 kHz or higher greatly improves sensitivity and resolution in both (1)H and (13)C SSNMR for paramagnetic systems such as Cu(II)(DL-alanine)(2)H(2)O (Cu(DL-Ala)(2)) and Mn(acac)(3), for which the spectral dispersions due to (1)H hyperfine shifts reach 200 and 700 ppm, respectively. Then, we introduce polarization transfer methods from (1)H spins to (13)C spins with high-power cross polarization and dipolar insensitive nuclei enhanced by polarization transfer (INEPT) in order to attain further sensitivity enhancement and to correlate (1)H and (13)C spins in two-dimensional (2D) SSNMR for the paramagnetic systems. Comparison of (13)C VFMAS SSNMR spectra with (13)C solution NMR spectra revealed superior sensitivity in SSNMR for Cu(DL-Ala)(2), Cu(Gly)(2), and V(acac)(3). We discuss signal assignment methods using one-dimensional (1D) (13)C SSNMR (13)C-(1)H rotational echo double resonance (REDOR) and dipolar INEPT methods and 2D (13)C(1)H correlation SSNMR under VFMAS, which yield reliable assignments of (1)H and (13)C resonances for Cu(Ala-Thr). Based on the excellent sensitivity/resolution and signal assignments attained in the VFMAS approach, we discuss methods of elucidating multiple distance constraints in unlabeled paramagnetic systems by combing simple measurements of (13)C T(1) values and anisotropic hyperfine shifts. Comparison of experimental (13)C hyperfine shifts and ab initio calculated shifts for alpha- and beta-forms of Cu(8-quinolinol)(2) demonstrates that (13)C hyperfine shifts are parameters exceptionally sensitive to small structural difference between the two polymorphs. Finally, we discuss sensitivity enhancement with paramagnetic ion doping in (13)C SSNMR of nonparamagnetic proteins in microcrystals. Fast recycling with exceptionally short recycle delays matched to short (1)H T(1) of approximately 60 ms in the presence of Cu(II) doping accelerated 1D (13)C SSNMR for ubiquitin and lysozyme by a factor of 7.3-8.4 under fast MAS at a spinning speed of 40 kHz. It is likely that the VFMAS approach and use of paramagnetic interactions are applicable to a variety of paramagnetic systems and nonparamagnetic biomolecules.
...
PMID:Progress in 13C and 1H solid-state nuclear magnetic resonance for paramagnetic systems under very fast magic angle spinning. 1826 15


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---