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Compound
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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Invasive pulmonary aspergillosis, usually caused by Aspergillus fumigatus, is a life-threatening condition of immunosuppressed patients. We have created a mutant strain of this fungus that lacks an extracellular alkaline protease (AFAlp). This was accomplished by transformation of A. fumigatus with a plasmid containing a selectable marker for hygromycin B resistance, and a 504 bp segment of the AFAlp gene, obtained by polymerase-chain-reaction-based amplification of A. fumigatus genomic DNA. Approximately 25% of transformants resulted from disruption of the AFAlp gene.
SDS
-polyacrylamide gel electrophoresis of proteins from the culture filtrate of a strain carrying the AFAlp gene disruption showed that it lacked a major protein of 33 kDa. Furthermore, in contrast to the culture filtrate from wild-type cells, the mutant had undetectable activity on azocollagen and elastin-Congo red, over a broad pH range. This shows that AFAlp accounts for most, if not all, of the extracellular elastinolytic activity of A. fumigatus, and that the mutant strain will be useful in assessing the role of AFAlp in pathogenicity.
Mol
Microbiol 1992 Jun
PMID:An Aspergillus fumigatus alkaline protease mutant constructed by gene disruption is deficient in extracellular elastase activity. 149 93
A DNA fragment containing the gene for a cell wall hydrolase of Bacillus licheniformis was cloned into Escherichia coli. Sequencing of the fragment showed the presence of an open reading frame which encodes a polypeptide of 253 amino acids with a molecular mass of 27,513. The gene was designated as cwlM, for cell wall lysis. The deduced amino acid sequence indicated that there is a repeated sequence consisting of 33 amino acid residues in the C-terminal region. Deletion of the C-terminal region did not lead to any loss of cell wall lytic activity. The gene product purified from E. coli cells harboring a cwlM-bearing plasmid exhibited a M(r) value of 29 kDa on
SDS
-polyacrylamide gels, and characterization of the specific substrate bond cleaved by CWLM indicated that the enzyme is an N-acetylmuramoyl-L-alanine amidase (EC 3.5.1.28). The enzyme hydrolyzed the cell wall of Micrococcus luteus more efficiently than those of B. licheniformis and B. subtilis, but the truncated CWLM (lacking the C-terminal region) had lost this preference. CWLM prepared from B. subtilis cells harboring a plasmid containing cwlM had a similar M(r) value to that from E. coli. Amino acid sequence homologies between CWLM and other amidases, and their protein structures are discussed.
Mol
Gen Genet 1992 Jul
PMID:Genetic structure, isolation and characterization of a Bacillus licheniformis cell wall hydrolase. 149 75
In Ciona intestinalis a chymotrypsin-like activity is involved in sperm penetration of the egg vitelline coat. A chymotrypsin-like enzyme has been purified from spermatozoa by a protocol including ion exchange chromatography, gel filtration, and native polyacrylamide gel electrophoresis. The purified enzyme resulted homogeneous when analyzed by
SDS
-PAGE. The molecular weight of the chymotrypsin-like enzyme was estimated to be 35 kDa by gel filtration and 24 KDa by
SDS
-PAGE in nonreducing conditions. The pH optimum of the enzyme is 8.4 and its activity is enhanced by Ca2+. It shows the highest activity towards the synthetic substrate Suc-Ala-Ala-Pro-Phe-AMC. Furthermore, by electron microscopy, the purified enzyme affects the structure of egg vitelline coat, and thus it fulfills one of the criteria of a lysin.
Mol
Reprod Dev 1992 Aug
PMID:Purification and characterization of a vitelline coat lysin from Ciona intestinalis spermatozoa. 149 86
We identified a rat sperm flagellar surface antigen using an IgG1 monoclonal antibody (MC31) against rat epididymal sperm. Avidin-biotin-peroxidase immunohistochemistry demonstrated that the antigen was first expressed in the cytoplasm of early primary spermatocytes, then gradually became restricted to the principal piece of the sperm flagellum during spermatogenesis. However, when the sperm reached the corpus epididymidis, the antigen was expressed on the surface of both the principal piece and the midpiece of the flagellum. The epithelial cells of the epididymis were not stained with MC31. Immunogold electron microscopy showed that the antigen was present on the surface of the sperm flagellar plasma membrane. Immunoblotting of Triton X-100 extracts of epididymal sperm after one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions demonstrated that MC31 detected a major antigen of 26,000-28,000 daltons (26-28K). Two-dimensional isoelectric focusing and
SDS
-PAGE indicated that the 26-28K antigen had an isoelectric focusing point (pl) of 5.8-5.3; minor antigens were also detected from 26K (pl 5.8) to 35K (pl 5.0). These results indicate that the antigen recognized by MC31 is an acidic 26-35K protein that originates in the testis, is integrated into the sperm flagellar plasma membrane of the principal piece during spermatogenesis, and then is expressed on the entire flagellar surface during epididymal transit.
Mol
Reprod Dev 1992 Aug
PMID:A rat sperm flagellar surface antigen that originates in the testis and is expressed on the flagellar surface during epididymal transit. 149 89
The biochemical nature and relationship between the different isoforms of acetylcholinesterase (AChEs) secreted by adult Nippostrongylus brasiliensis was investigated, primarily via staining for enzyme activity and active-site labelling with [3H]-diisopropylfluorophosphate (DFP). Analysis by 1-dimensional
SDS
-PAGE under non-reducing conditions revealed the existence of 2 proteins of 74-kDa and 39-kDa, and each protein resolved as 2 species by isoelectric focusing. Both AChEs were co-purified via affinity chromatography on 9-[N beta-(epsilon-aminocaproyl)-beta-aminopropylamino]-acridine-coupled Sepharose 6B, and utilised to raise a polyclonal rabbit antiserum. Examination of the expression of secretory AChEs by adult worms during their residence in the gastrointestinal tract showed that the initial secretion of both forms on day 4 post-infection switched to predominant secretion of the 39-kDa protein by day 8. Immunoprecipitation of 35S-labelled products of in vitro translation via RNA from day 4 and day 8 worms predicted a single primary translation product of 59 kDa. These data suggested that the 'switching' event seen in vivo most likely corresponded to processing of the 74-kDa molecule. This interpretation was supported by limited digestion with V8 protease and chymotrypsin, which showed that the 74-kDa and the 39-kDa proteins possessed structural similarities.
Mol
Biochem Parasitol 1992 Jul
PMID:Characterisation of the secretory acetylcholinesterases from adult Nippostrongylus brasiliensis. 150 47
Protein P126 (also called P140, P113, SERA, SERP1) is a major parasitophorous vacuole antigen of Plasmodium falciparum. This protein is processed upon merozoite release into 2 fragments of 73 kDa (P73) and 50 kDa (P50), which are found in the culture medium. P73 is composed of 2 polypeptides of 47 and 18 kDa linked by disulfide bridges. In the presence of leupeptin, an inhibitor of serine and cysteine proteases which inhibits merozoite release, a 56-kDa intermediate product (P56) is recovered in the culture medium instead of P50. In order to map these proteolytic fragments on the 126-kDa precursor, we purified them from Plasmodium falciparum culture medium by immunoadsorption,
SDS
-electrophoresis and Western blotting on PVDF membrane and determined the N termini of P126, P73 (P47 and P18), P50 and P56. Comparison of these sequences with the amino acid sequence deduced from the P126 gene allowed the mapping of the different fragments on the precursor. P47 was at the N-terminal and P18 at the C-terminal end of P126. P56 and P50 had the same N-termini and were located in the middle of P126. This latter result indicates that the proteolysis of P56-P50 occurs at the C-terminus of P56. The peptide bonds cleaved by leupeptin-insensitive activities are Glu-Thr and Gln-Asp; C-terminal sequencing of P50 will be needed to identify the leupeptin-sensitive cleavage site.
Mol
Biochem Parasitol 1992 Jul
PMID:Intramolecular mapping of Plasmodium falciparum P126 proteolytic fragments by N-terminal amino acid sequencing. 150 48
In the mole crab Emerita asiatica, the main yolk proteins consist of two slow moving lipovitellins (Lv I and Lv II) of glycolipoprotein nature. Lv I cleaves into subunits (MW: 109,000 and 105,000) and Lv II gives rise to six subunits (MW: 65,000, 54,000, 50,000, 47,000, 44,000, and 42,000) in
SDS
-PAGE (with beta-mercaptoethanol). In order to observe the stability of Lv II as well as to achieve better resolution of the proteins, two different buffer systems (Phosphate buffered saline and tris-buffered saline), 40% sucrose, and glass distilled water were used as homogenizing media. Among them, better resolution was achieved with tris-buffered saline and 40% sucrose, and tris-buffered saline seems to be the ideal medium for elution of Lv II. The analysis of biochemical constituents of the major Lv II reveals a percentage composition of 69.325, 27.927, and 2.753 respectively for protein, lipid, and bound sugars. In the I stage embryo, protein comprises about 67.276%, lipid 29.65%, and bound sugars 3.015%. Vitellogenin (Vg) electrophoretically corresponding to the Lv I and Lv II was present in the female haemolymph during the entire period of embryogenesis. The number of subunits (8) of Vg in all stages remained unaltered and their approximate molecular weights were Vg1, 91,000; Vg2, 87,000; Vg3, 83,000; Vg4, 61,000; Vg5, 58,000; Vg6, 45,000; Vg7, 42,000; and Vg8, 38,000. Different proteins present in the embryos (I and IV stage) and the serum obtained from the animal carrying the I stage embryo were separated by gel-filtration in high performance liquid chromatography (HPLC). Sephadex (G-200) gel filtration chromatography was used to purify the Lv II in large quantity. Total lipid extracted from Lv II as well as the embryos belonging to different stages of development were separated into their constituent neutral, glycolipids, and phospholipids, using silicic acid column chromatography. Thin layer chromatography (TLC) was used to isolate the different phospholipids purified from various stages of embryos and Lv II. As many as seven different phospholipids were separated from Lv II and I and IX stage embryos; and whereas thin layer chromatogram of V and VI stage embryos showed six different phospholipids, embryos of VII and VIII stage contained four phospholipid species. Cholesterol, glycolipids, and individual phospholipids isolated from the Lv II and I stage embryo were quantified spectrophotometrically and the results were discussed.
Mol
Reprod Dev 1992 Sep
PMID:Purification and characterization of vitellogenin and lipovitellins of the sand crab Emerita asiatica: molecular aspects of crab yolk proteins. 151 Aug 41
Biochemical and immunoelectron microscopic methods have been used to analyze the distribution of actin in boar spermatozoa and its state of aggregation before and after acrosome reaction. F-actin was detected on sperm head and tail by electron microscopy using an improved phalloidin probe: incubation with a fluorescein-phalloidin complex and an anti-fluorescein antibody, followed by labeling with protein A-gold complex. Gold particles, indicating the presence of F-actin, were localized on the sperm surface of the acrosome-reacted spermatozoa. Specific labeling was localized (1) between the outer acrosomal membrane and the plasma membrane in the equatorial region, (2) between the outer surface of the fibrous sheath and the plasma membrane in the postacrosomal region, (3) around the connecting piece and the neck region, and (4) on the external surface of the fibrous sheath in the principal piece of the tail. Furthermore, after NP-40 extraction, the
SDS
-PAGE revealed a difference in solubility between reacted and unreacted boar spermatozoa, reflecting actin polymerization. We conclude that most actin in the acrosome reacted boar spermatozoa is polymeric.
Mol
Reprod Dev 1992 Sep
PMID:F-actin in acrosome-reacted boar spermatozoa. 151 Aug 50
Phaseolin is a glycoprotein that constitutes the major storage protein in bean seeds. The phaseolin gene promoters function in a seed-specific manner. In an attempt to understand if events following transcription of the gene also contribute to the seed-specific accumulation of the phaseolin protein, we studied the effect of substituting the constitutive CaMV-35S promoter for the beta-phaseolin gene promoter on expression of the phaseolin gene in different plant organs. A chimeric gene consisting of the 35S promoter, the coding sequence of the beta-phaseolin gene (all five introns and six exons) and the 3'-flanking region of the beta-phaseolin gene, was introduced into alfalfa via Agrobacterium tumefaciens. While all organs examined shared high levels of phaseolin transcripts, the only organ that showed significant accumulation of the phaseolin protein were the mature seeds. Co-migration of the major immunoreactive polypeptides from the non-seed organs with the authentic beta-phaseolin polypeptides on
SDS
-PAGE indicates that the protein in non-seed organs undergoes correct post-translational processing and modification, but are more unstable in a non-seed environment.
Plant
Mol
Biol 1992 Sep
PMID:Constitutive expression of the beta-phaseolin gene in different tissues of transgenic alfalfa does not ensure phaseolin accumulation in non-seed tissue. 151 Nov 40
Graves' disease is an autoimmune thyroid disease characterized by the presence of pathogenic autoantibodies to the TSH receptor (TSH-R). By using polymerase chain reaction, the extracellular region of the human TSH-R cDNA has been amplified and used to prepare recombinant TSH-R (extracellular) protein fused with glutathione-S-transferase (GST). Purification of the recombinant TSH-R (extracellular)-GST fusion protein was achieved by preparative gel electrophoresis in
SDS
or by preparative isoelectric focusing in urea. Following removal of
SDS
by detergent exchange or urea by dialysis, the purified recombinant receptor preparations were assessed for binding to the hormone or to autoantibodies from Graves' disease patients. The purified recombinant receptor preparations fail to show any binding to the hormone or autoantibodies either by inhibition of binding assays or by immunoblotting. The results imply that the correct folding and/or post-translational modifications of the polypeptide chain which are not achieved in recombinant proteins produced in Escherichia coli may be important for the binding of the hormone or Graves' disease autoantibodies to the TSH-R. The recombinant receptor prepared in this manner will be useful for immunological and cellular investigations in patients with Graves' disease.
J
Mol
Endocrinol 1992 Apr
PMID:Expression of a human thyrotrophin receptor fragment in Escherichia coli and its interaction with the hormone and autoantibodies from patients with Graves' disease. 151 18
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