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Query: EC:3.4.21.4 (
trypsin
)
42,187
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Surface antigenic variation was investigated in
Mycoplasma
arthritidis, an agent that produces chronic arthritis in rats which shares several features with many
mycoplasma
-induced diseases and thus defines a well-characterized model system. Hyperimmune rabbit antisera (anti-ISR1, anti-PG6, anti-H606 and anti-158p10) to whole M. arthritidis organisms were used as immunological probes in Western immunoblots of four M. arthritidis prototype strains (ISR1, PG6, H606 and D263) and five rat-passaged substrains (ISR1p1, ISR1p7, ISR1p8, 158p10 and D263p1). Several prominent antigens were identified that varied in expression. By Triton X-114 phase fractionation and treatment of whole cells with
trypsin
and carboxypeptidase Y, these strain-variant antigens were shown to be integral membrane proteins with C-termini and portions of the polypeptide chains oriented outside the membrane. Western blot immunoscreening of a large number of randomly selected clonal isolates and well-established clonal lineages from stock cultures of M. arthritidis ISR1p7, 158p10, PG6 and H606 revealed an expanded repertoire of variant membrane proteins whose expression was subject to independent, reversible phase variation. Colony immunoblots of these clonal populations with a hyperimmune rabbit antiserum to a gel-purified variant membrane protein (P36) showed that this phase switching occurred at a high frequency (10(-4) to 10(-2) per generation). Detailed immunological and biochemical characterization of the phase-variant membrane proteins demonstrated that they are: (i) antigenically related or distinct; (ii) apparently specific to particular strain populations; (iii) proteins or lipoproteins; (iv) major immunogens of M. arthritidis, recognized by serum antibodies from convalescent rat; and (v) able to undergo variation in expression during in vivo passage. Thus, M. arthritidis possesses a complex system capable of creating large repertoires of cell surface phenotypes which may affect the multiple interactions of this organism with its host and dictate its potential as a successful infectious agent and pathogen.
...
PMID:Major membrane proteins and lipoproteins as highly variable immunogenic surface components and strain-specific antigenic markers of Mycoplasma arthritidis. 857 12
Mycoplasma
bovis is a causative agent of bovine mastitis, arthritis, and pneumonia. Six monoclonal antibodies (MAbs) against M. bovis were prepared and used to characterize specific antigens of the
mycoplasma
. Reactivity of the MAbs to six M. bovis strains was tested by IFA, ELISA, and immunoblotting. The specificity of these MAbs was tested by the same methods against 8 other species of bovine mycoplasmas and 1
mycoplasma
species of sheep and goats (
Mycoplasma
agalactiae) that is highly cross-reactive with M. bovis. Three of the MAbs were used on Western blots of
trypsin
-treated whole organisms to determine if the antigens were exposed on the surface of M. bovis By isotyping, MAbs were identified as kappa chain IgG1 (3 MAbs), and IgM (3MAbs). The MAbs reacted with all six M. bovis strains in IFA, ELISA, and Western blots. Four of the antigens recognized were highly specific for M. bovis in ELISA, and 3 were cross-reactive with M. agalactiae or other bovine mycoplasmas in Western blots. One MAb reacted with multiple bands with all M. bovis strains, indicating recognition of a size-variant antigen. The size-variant antigen and one of the M. bovis-specific antigens were recognized as surface proteins. A large M. bovis-specific antigen was a conserved cytosolic protein. The M. bovis antigens discovered may be used for specific detection of the organism or measurement of antibody responses, particularly if used in tests with nondenatured alkali-treated antigen, such as ELISA.
...
PMID:Membrane-associated and cytosolic species-specific antigens of Mycoplasma bovis recognized by monoclonal antibodies. 857 97
A 150-kDa cytadhesin-like protein from
Mycoplasma
gallisepticum has been identified. A previously described 583-bp fragment (J.E. Dohms, L.L. Hnatow, P. Whetzel, R. Morgan and C.L. Keeler, Jr., Avian Dis. 37:380-388, 1993) was used to probe a genomic library of M. gallisepticum DNA. An 8.0-kb SacI fragment was identified, cloned, and partially sequenced. Analysis of the resulting 3,750-bp sequence revealed the presence of a 3,366-nucleotide open reading frame, mgc1. The 1,122-amino-acid protein encoded by this open reading frame, MGC1, has characteristics of a class I membrane protein and has homology with the MgPa cytadhesin of
Mycoplasma
genitalium (26.3%) and the P1 cytadhesin of
Mycoplasma
pneumoniae (28.7%). A portion of MGC1 was expressed as a glutathione S-transferase fusion protein and used to produce antiserum in rabbits. The antiserum recognizes a 150-kDa protein from M. gallisepticum. The protein is sensitive to
trypsin
, confirming that it is surface exposed. Primer extension analysis indicates that the mgc1 RNA starts within an upstream open reading frame, suggesting complex control of its expression. This is the first description of a functional gene from M. gallisepticum showing homology to cytadhesin genes from human mycoplasmas.
...
PMID:Cloning and characterization of a putative cytadhesin gene (mgc1) from Mycoplasma gallisepticum. 861 58
With the aim of characterizing specific immunogenic proteins of
Mycoplasma
mycoides subsp. mycoides small colony (SC) type, the aetiological agent of contagious bovine
pleuropneumonia
, a gene encoding a major immunogenic protein of 72 kDa named P72 was cloned and expressed in Escherichia coli. The expressed protein was of the same apparent molecular mass as that produced by the parent strain. The predicted molecular mass of P72, based on the DNA-deduced amino acid sequence, was 61.118 kDa, significantly lower than the apparent molecular mass of endogenous or recombinant P72 on SDS-PAGE. Analysis of the amino acid sequence revealed a typical prokaryotic signal peptidase II-membrane lipoprotein lipid attachment site and a transmembrane structure domain in the leader sequence at the amino-terminal end of the protein. P72 was shown to be a lipoprotein and its surface location was confirmed by
trypsin
treatment of whole cells. An unassigned gene encoding a peptide with some similarity to P72 was found on the genome sequence of M. capricolum subsp. capricolum but not on that of
Mycoplasma
genitalium. The P72 gene was detected in 11/11 M. mycoides subsp. mycoides SC strains. Antiserum against recombinant P72 reacted strongly with 12/12 strains of M. mycoides subsp. mycoides SC, weakly with
Mycoplasma
bovine group 7 strain PG50, but not with other members of the 'mycoides cluster' or closely related mycoplasmas. Cows experimentally contact-infected with M. mycoides subsp. mycoides SC developed a humoral response against P72 within 35 d. P72 is a specific antigenic membrane lipoprotein of M. mycoides subsp. mycoides SC with potential for use in development of diagnostic reagents. It seems to belong to a family of lipoproteins of the "mycoides cluster'.
...
PMID:Characterization of the gene for an immunodominant 72 kDa lipoprotein of Mycoplasma mycoides subsp. mycoides small colony type. 900 14
Adherence of
Mycoplasma
gallisepticum to erythrocytes was examined by colony immunoblotting, detergent phase fractionation,
trypsin
treatment, comparison of protein profiles, and comparison of erythrocyte-bound
mycoplasma
protein fractions of hemadsorption-positive and -negative mutants. The binding of M. gallisepticum to chicken or human erythrocytes was found to be mediated via surface-exposed membrane proteins undergoing high-frequency phase variation.
...
PMID:Adherence of Mycoplasma gallisepticum involves variable surface membrane proteins. 916 93
Monoclonal antibody (MAb) E8-18 reacted with four isolates of
Mycoplasma
capricolum subsp. capripneumoniae in Western blots identifying an epitope on a 24 kDa antigen (p24). MAb E8-18 did not react with 11 isolates belonging to four other
Mycoplasma
species or subspecies closely related to M. capricolum subsp. capripneumoniae. A combination of
trypsin
treatment of intact organisms and detergent-phase partitioning revealed p24 to be an integral M. capricolum subsp. capripneumoniae surface membrane protein.
...
PMID:Monoclonal antibody E8-18 identifies an integral membrane surface protein unique to Mycoplasma capricolum subsp. capripneumoniae. 930 16
Six isolates of
Mycoplasma
bovoculi obtained from cattle herds with bovine keratoconjunctivitis were analyzed by gel electrophoresis and immunoblotting techniques. All six strains showed similarity in their protein profiles although no two patterns were identical. Antigenic differences between strains were detected in immunoblots reacted with post-exposure calf serum. A common 94 kDa protein band designated p94 was detected in all six strains reacted with monoclonal antibody MA25.5 developed to one of the strains. The p94 was also recognized in these strains by the calf serum. Trypsin treatment of intact
mycoplasma
cells resulted in the removal of p94 from immunoblots reacted with MA or hyperimmune rabbit serum. Other
trypsin
-resistant antigens shared between strains or being strain-specific in nature were identified when
trypsin
-treated
mycoplasma
cells were reacted with hyperimmune rabbit serum. The p94 antigen was shown to be of mycoplasmal origin by radio-immunoprecipitation using the MA or hyperimmune rabbit serum. These studies identify the presence of a surface antigen (p94) on M. bovoculi membrane in all strains examined that is
trypsin
sensitive by the use of monoclonal antibody, calf serum and hyperimmune rabbit serum.
...
PMID:Identification and localization of a 94 kDa membrane protein found in Mycoplasma bovoculi strains. 977 58
The protein and antigen profiles of 60 isolates, strains and the type strain PG1 of
Mycoplasma
mycoides subsp. mycoides s.c. were compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblot analysis. Analysis using contagious bovine
pleuropneumonia
antisera and hyperimmune rabbit sera against several representative strains revealed some differences in protein profiles and variability in antigens among strains from different geographic regions. The most common antigenic bands had the molecular masses of 110, 95, 80, 69, 62, 60, 48, 44, 39 and 38 kDa. There were differences among European strains, where a larger group coming from Italy lacked the p98 antigen, thus, with one exception, distinguishing the Italian strains from Portuguese, French and Spanish strains. African, Australian and PG1 strains showed heterogenic profiles, with quantitative differences and in a few strains some antigenic bands were absent. The group constituting African, Australian and PG1 strains was characterised by the presence of 71.5/70 kDa antigens, which were not detected in European strains.
Mycoplasma
mycoides subsp. mycoides s.c. membrane proteins were characterised by Triton X-114 partitioning and p110, p98, p95, p62/60 and p48 were identified as immunogenic antigens. The simultaneous presence of these five antigens was common to all the sera examined and, therefore, indicates the diagnostic potential of immunoblotting. Most immunodominant antigens are surface-exposed proteins as determined by the
trypsin
treatment.
...
PMID:Antigen heterogeneity among Mycoplasma mycoides subsp. mycoides SC isolates: discrimination of major surface proteins. 981 Jun 18
The identification of a gene (gapA) from
Mycoplasma
gallisepticum with homology to the P1 cytadherence gene of
Mycoplasma
pneumoniae is reported. The gapA gene is a 2895 bp ORF encoding a protein with a molecular mass of 105 kDa. Nucleotide sequence analysis of the gapA gene revealed 45% homology to the M. pneumoniae P1 gene, 46% homology to the
Mycoplasma
genitalium MgPa gene and 47% homology to the
Mycoplasma
pirum P1-like protein gene. It has a 64 mol % A+T content compared to 46, 60 and 72 mol % respectively for the P1, MgPa and the P1-like protein genes. As with the P1 and MgPa genes, gapA is a central gene in a multi-gene operon, but unlike the P1 and MgPa genes, there is only a single copy of gapA in the genome. GapA is a
trypsin
-sensitive surface-exposed protein. Chicken tracheal-ring inhibition-of-attachment assays, using anti-GapA Fab fragments, resulted in 64% inhibition of attachment. These results indicated that GapA plays a role in cytadherence of M. gallisepticum to host cells.
...
PMID:Molecular and biochemical analysis of a 105 kDa Mycoplasma gallisepticum cytadhesin (GapA). 984 32
Membrane nucleases of mycoplasmas are believed to play important roles in growth and pathogenesis, although no clear evidence for their importance has yet been obtained. As a first step in defining the function of this unusual membrane activity, studies were undertaken to clone and analyze one of the membrane nuclease genes from
Mycoplasma
pulmonis. A novel screening strategy was used to identify a recombinant lambda phage expressing nuclease activity, and its cloned fragment was analyzed. Transposon mutagenesis was used to identify an open reading frame of 1,410 bp, which coded for nuclease activity in Escherichia coli. This gene coded for a 470-amino-acid polypeptide of 53,739 Da and was designated mnuA (for "membrane nuclease"). The MnuA protein contained a prolipoprotein signal peptidase II recognition sequence along with an extensive hydrophobic region near the amino terminus, suggesting that the protein may be lipid modified or that it is anchored in the membrane by this membrane-spanning region. Antisera raised against two MnuA peptide sequences identified an M. pulmonis membrane protein of approximately 42 kDa by immunoblotting, which corresponded to a
trypsin
-sensitive nucleolytic band of the same size. Maxicell experiments with E. coli confirmed that mnuA coded for a nuclease of unknown specificity. Hybridization studies showed that mnuA sequences are found in few
Mycoplasma
species, suggesting that
mycoplasma
membrane nucleases display significant sequence variation within the genus
Mycoplasma
.
...
PMID:Cloning of mnuA, a membrane nuclease gene of Mycoplasma pulmonis, and analysis of its expression in Escherichia coli. 1007 79
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