Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

On SDS-PAGE, solubilized and proteinase K treated preparations of Neisseria gonorrhoeae strain BS4 (agar) showed differences in silver stained lipopolysaccharide (LPS) patterns, before and after induction to resistance to serum killing by incubation for 3 h at 37 degrees C with low Mr fractions from lysates of guinea pig red blood cells. Preparations from the original serum susceptible gonococci and LPS purified from such bacteria showed two components, but the preparations from the serum resistant gonococci were deficient in the higher Mr component. Furthermore, on immunoblotting with fresh human serum (FHS), the two LPS components of the susceptible gonococci reacted strongly with IgM. With preparations from the serum resistant gonococci there was no reaction in the area corresponding to the higher Mr component and a weaker reaction with the component of low Mr. Purified LPS from the susceptible gonococci neutralized the bactericidal activity of FHS against N. gonorrhoeae strain BS4 (agar) probably by reacting with the relevant antibody, since heated FHS was no longer bactericidal when mixed with a source of complement (human placental serum) after prior reaction with the LPS. These neutralization tests coupled with the results of immunoblotting strongly suggest that increased serum resistance is due to the lack of the high Mr LPS moiety.
 ...
PMID:Lipopolysaccharide alteration is associated with induced resistance of Neisseria gonorrhoeae to killing by human serum. 309 92

Analyses of chemical composition in whole cells of Rickettsia tsutsugamushi were performed and compared with those of the other rickettsiae and gram-negative bacteria. The results indicated that R. tsutsugamushi does not contain detectable amounts of 3-deoxy-D-mannooctulosonic acid, heptose, muramic acid, or glucosamine (less than 2, less than 2, less than 3, and less than 3 nmol/mg, respectively). The microorganism was found to contain four kinds of fatty acids (16:0, 18:0, 18:1, and 18:2), but not hydroxy fatty acids. Furthermore, in analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver or Coomassie blue staining, lipopolysaccharide bands were not detected in preparations treated with proteinase K. It is concluded that R. tsutsugamushi has little or no peptidoglycan or lipopolysaccharide.
 ...
PMID:Deficiency of peptidoglycan and lipopolysaccharide components in Rickettsia tsutsugamushi. 311 50

A gonococcal gene bank maintained in Escherichia coli K-12 was screened by colony immunoblotting, and a transformant expressing a surface antigen reactive to anti-gonococcal outer membrane antiserum was isolated. The isolate carried a recombinant plasmid, pTME6, consisting of approximately 9 kilobases of Neisseria gonorrhoeae DNA inserted into the BamHI site of pBR322. Surface labeling of E. coli HB101(pTME6) confirmed that the antigen was expressed on the E. coli cell surface. The antigenic material was resistant to proteinase K digestion and sensitive to periodate oxidation, indicating that the material was carbohydrate. Purified lipopolysaccharide (LPS) from HB101(pTME6) produced a unique band on silver-stained polyacrylamide gels that contained immunoreactive material as seen on Western blots of LPS samples. Only two of three E. coli LPS mutant strains carrying pTME6 reacted with the antigonococcal antiserum, suggesting that a certain E. coli core structure is necessary for antigen expression. We conclude that pTME6 contains one or more gonococcal genes encoding an LPS core biosynthetic enzyme(s) which can modify E. coli core LPS to produce a gonococcuslike epitope(s).
 ...
PMID:Expression of a cloned lipopolysaccharide antigen from Neisseria gonorrhoeae on the surface of Escherichia coli K-12. 311 95

Recently evidence has been obtained that a minute amount of cytidine 5'-monophospho-N-acetyl neuraminic acid (CMP-NANA) or a closely related compound is the low Mr factor in human red blood cells which induces Neisseria gonorrhoeae (BS4(agar] to resistance to killing by fresh human serum. Induction of gonococci to resistance by both CMP-NANA and semi-purified low Mr factor from red blood cells was accompanied by a 35-55% reduction of silver staining of lipopolysaccharide separated in SDS-PAGE gels of proteinase K digests. These alterations in lipopolysaccharide are probably responsible for conferring serum resistance. However, lipopolysaccharide-containing digests from resistant as well as from susceptible gonococci neutralised serum bactericidal activity. These observations may have wider implications since CMP-NANA is a sialylating agent wide-spread in mammalian tissues and LPS is ubiquitous amongst Gram-negative pathogens.
 ...
PMID:Cytidine 5'-monophospho-N-acetyl neuraminic acid and a low molecular weight factor from human blood cells induce lipopolysaccharide alteration in gonococci when conferring resistance to killing by human serum. 314 16

Lipopolysaccharide affects a variety of eukaryotic cells and mammalian organisms. These actions are involved in the pathogenesis of Gram-negative septicemia. Many of the actions of lipopolysaccharide are believed to be caused by its active moiety, lipid A. Our laboratory has previously identified a bioactive lipid A precursor, termed lipid IVA (Raetz, C. R. H., Purcell, S., Meyer, M. V., Qureshi, N., and Takayama, K. (1985) J. Biol. Chem. 260, 16080-16888), which can be labeled with 32P of high specific activity and purified. In this work we have used the labeled probe, 4'-32P-lipid IVA, to develop a novel assay for the specific binding of lipid IVA to whole cells. We have also demonstrated its use in a ligand blotting assay of immobilized cellular proteins. Using the whole cell assay, we show that 4'-32P-lipid IVA specifically binds to RAW 264.7 macrophage-like cultured cells. The binding is saturable, is inhibited with excess unlabeled lipid IVA, and is proteinase K-sensitive. It displays cellular and pharmacological specificity. Using the ligand blotting assay, we show that several RAW 264.7 cell proteins can bind 4'-32P-lipid IVA. The two principal binding proteins have Mr values of 31 and 95 kDa, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Fractionation studies indicate that the 31-kDa protein is enriched in the nuclear fraction and may be a histone, whereas the 95-kDa protein is enriched in the membrane fraction. The binding assays that we have developed should lead to a clearer understanding of lipid A/animal cell interactions.
 ...
PMID:Lipid A binding sites in membranes of macrophage tumor cells. 317 May 65

The sensitivity and specificity of an immune dot blot test (IDBT), which relies on a 125I-labeled genus-specific monoclonal antibody to detect the Chlamydia lipopolysaccharide (LPS) antigen, were improved by pretreatment of specimens with proteinase K. This enzyme destroys protein A and therefore eliminates false-positive reactions caused by the presence of Staphylococcus aureus. Proteinase K treatment also improved the ability of the assay to detect the Chlamydia LPS antigen. When the improved IDBT was compared with culture for detection of C. trachomatis in 1,394 urogenital specimens obtained from a genitourinary medicine clinic, the overall sensitivity was 96%, and LPS antigen was detected in 76 of 83 (92%) specimens that yielded less than 10 inclusions in culture. The specificity and positive and negative predictive values of the test were 97, 81.5, and 99%, respectively. Of 123 conjunctival swabs, 7 were positive by both tests and 4 swabs were positive only by IDBT. This improved IDBT provides a simple, reliable alternative to culture for the detection of C. trachomatis in urogenital and conjunctival specimens.
 ...
PMID:Sensitive immune dot blot test for diagnosis of Chlamydia trachomatis infection. 318 26

The techniques of capsular serotype, biotype determination and sodium dodecylsulphate polyacrylamide gel electrophoresis of sarcosinate-insoluble outer membrane protein (OMP) and of proteinase K lipopolysaccharide (LPS) preparations were applied to 41 genital and neonatal Haemophilus influenzae isolates. Twelve percent were capsulated (4b, 1a). Distribution of strains between biotypes was similar to that of isolates of other non-systemic pathogenic origin; only one isolate was biotype IV. The OMP profiles showed great variability with 4 group of proteins: a 16-Kd major peptide which was observed in all strains; 27-30-Kd major OMP including one constant 30-Kd peptide present in all strains except one; 32- to 50-Kd major OMP; and 49- to 54-Kd minor OMP. The rough LPS profiles also revealed heterogeneity. In view of the variability observed among H. influenzae strains, it is not possible to establish a relationship between pathogenicity and a macromolecular marker.
 ...
PMID:[Heterogeneity of strains of Haemophilus influenzae of genital and neonatal origin: analysis of capsular serotypes, biotypes and electrophoretic profiles of external membrane proteins and LPS]. 350 Jul 32

To determine whether lipopolysaccharide (LPS) structures of Campylobacter fetus are related to the three known heat-stable serogroups, proteinase K-treated whole cell lysates obtained from strains of each serogroup were electrophoresed in polyacrylamide gels. All strains had smooth-type LPS with multiple high-molecular-weight repeating units. The profiles of serogroup A from C. fetus subsp. fetus and from C. fetus subsp. venerealis were identical, but they were different from those of C. fetus subsp. fetus serogroups B and AB. When we immunoblotted the LPS of these serogroups with normal or immune rabbit serum we found homologous recognition between serogroups A from C. fetus subsp. fetus and C. fetus subsp. venerealis. Similarly, serogroups AB and B from C. fetus subsp. fetus showed homologous recognition. However, antiserum against serogroup A did not recognize serogroups B and AB and vice versa. Absorption studies confirmed the identity of LPS from all serogroup A C. fetus strains and cross-reactivity of the serogroup B and AB strains with one another. Serogroup A strains were resistant to the bactericidal activity in normal human serum, whereas serogroup B and AB strains generally were susceptible; isolates from humans predominantly belonged to serogroup A. Results of these studies suggest that the LPS composition forms the basis for the heat-stable serotyping system for C. fetus and that the structural and antigenic variants are associated with differential serum susceptibility.
 ...
PMID:Lipopolysaccharide structures of Campylobacter fetus are related to heat-stable serogroups. 351 Jan 69

Sera from pigs infected with Haemophilus (Actinobacillus) pleuropneumoniae were tested for antibodies to outer membrane proteins (OMPs) of the organism by immunoblotting. Convalescent sera were produced in naturally born, colostrum-fed pigs and in cesarean-derived, colostrum-deprived pigs given H. pleuropneumoniae serotype 5 intranasally twice at 5-week intervals. Sera, collected at weekly intervals, were reacted with Sarkosyl-insoluble, OMP-enriched preparations of H. pleuropneumoniae which had been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrophoretically transferred to nitrocellulose. Antibodies were detected to OMPs with an apparent molecular weight of 16,500 (16.5K OMP); to 29K, 38.5K, 43.5K, 45K, 49.5K, and 66.5K OMPs; and to several high-molecular-weight (greater than or equal to 94,000) OMPs, but not to the major 42K OMP. Antibodies to the heat-modifiable OMP (29K/43.5K) and the 38.5K OMP were detected in sera from noninfected pigs. Antibodies were also detected to two broad 54,000- and 95,000-molecular-weight bands which did not stain with Coomassie blue, stained with silver nitrate, resisted proteinase K digestion, and were eliminated by oxidation with sodium metaperiodate. This indicates that the 54,000- and 95,000-molecular-weight bands represent polysaccharide, possibly capsular or lipopolysaccharide immunogens. Adsorption of sera with cells from the homologous serotype 5 strain removed antibodies to the 45K, 49.5K, 66.5K, and greater than or equal to 94K OMPs and to the two polysaccharide bands, indicating that these antibodies were directed primarily to surface-exposed epitopes. When tested with OMP preparations from other serotype 5 strains, heterogeneity was apparent, both in the reactions with OMPs and with the polysaccharide bands. Silver staining of proteinase K-treated, whole-cell lysates from serotype 5 strains also indicated variable expression of the polysaccharide bands. Sera also reacted with OMPs from H. pleuropneumoniae serotypes 1 and 7; however, several OMPs and the lipopolysaccharide or polysaccharide determinants of these serotypes appeared to be type specific.
 ...
PMID:Antibody response of swine to outer membrane components of Haemophilus pleuropneumoniae during infection. 353 48

We examined Escherichia coli K-12 lipopolysaccharide (LPS), which is known to be an R-form LPS, for its ability to form a hexagonal lattice structure in vitro. The LPS from E. coli K-12 strain JE1011 did not form a hexagonal lattice structure when it was precipitated by addition of two volumes of 10 mM MgCl2-ethanol, but it did form such a structure when it was electrodialyzed and then converted to the magnesium or calcium salt form. The lattice constant of the magnesium salt form was 15.2 +/- 0.3 nm and that of the calcium salt form 18.5 +/- 0.3 nm. Since prior treatment of the LPS with proteinase K in the presence of sodium dodecyl sulfate did not affect its capability of hexagonal assembly, the lattice formation by the LPS does not require the presence of proteins.
 ...
PMID:In vitro hexagonal assembly of lipopolysaccharide of Escherichia coli K-12. 354 25


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