Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.1.1.69 (BMT)
 2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

4-Hydroxyphenylpyruvic acid dioxygenase is an important enzyme in tyrosine catabolism in most organisms. From porcine and human liver cDNA libraries we isolated complementary DNA inserts for the enzyme. Protein sequence analysis of the porcine enzyme revealed a block of the amino terminus of the mature enzyme. Comparison of the amino acid sequence determined by Edman degradation of peptides derived from porcine liver 4-hydroxyphenylpyruvic acid dioxygenase with the nucleotide sequences revealed the primary structure of the porcine and human enzymes. The mature human and porcine enzymes have an 89% amino acid sequence identity in amino acid residues and are composed of 392 amino acid residues. A computer-assisted homology search revealed that the enzyme is 88% identical in amino acid sequence to rat liver-specific alloantigen F. A monoclonal antibody (mob 51), which can immunoprecipitate both the human and porcine enzymes, was developed. Cultured BMT-10 cells transfected with the cDNA insert of the human enzyme, using the expression vector pCAGGSneodE, produced a polypeptide with an M(r) of 43,000, which was immunoprecipitated with mob 51. Enzymic activity of the enzyme was detected in the transfected cells but not in the mock transfected cells. These findings suggest that the human 4-hydroxyphenylpyruvic acid dioxygenase is a homodimer of two identical subunits with an M(r) of 43,000. Liver-specific alloantigen F seems to be closely related to the enzyme or possibly to the subunit of the enzyme itself. Elucidation of the complete amino acid sequence of the enzyme is expected to reveal structure-function relationships of this metabolically important enzyme and to shed light on inherited disorders related to tyrosine metabolism, especially tyrosinemia types 1 and 3.
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PMID:Primary structure deduced from complementary DNA sequence and expression in cultured cells of mammalian 4-hydroxyphenylpyruvic acid dioxygenase. Evidence that the enzyme is a homodimer of identical subunits homologous to rat liver-specific alloantigen F. 133 42

The clonal expression of tumor rejection Ag (TRA) was analyzed on nine different clones derived from parental BALB3T3 cells that were transfected with activated H-ras, polyoma middle T (PyMT), c-myc, and v-src oncogenes. It was shown that Bras-h clone, which is an activated H-ras oncogene-induced transformant, expressed TRA as assessed in the transplantation study using syngeneic BALB/c mice. This TRA was not detected on parental BALB3T3 nontransformed cells, suggesting that TRA could be expressed in the BALB3T3 cell transformation. Furthermore, the cross-protection experiments indicated that this TRA was also conferred on other BALB3T3 transformants with high anchorage-independent growth potential such as an activated H-ras transformant Bras-d, and PyMT transformants BMT-f, BnMT-11, BnMT-20, except in the case of one H-ras transformant Bnr-12. In contrast, this TRA was not expressed on the transfectants with little or no anchorage independent growth potential such as a PyMT transfectant BnMT-4, a c-myc transfectant Bmyc-7, and a v-src transfectant Bsrc-7. We developed the mAb BRH19 that could react with TRA+ clones but not with TRA- clones. This mAb makes an immunoprecipitate, which is composed of a 50-kDa single polypeptide chain from Bras-h cell lysate. An injection to mice with this antigen could confer the protection against Bras-h challenge. These data indicate that the 50-kDa putative TRA molecule could be expressed in close association with the cell transformation, irrespective of the introduced oncogenes, and there may exist some regulatory mechanisms rather than individually distinct manners for the expression of TRA.
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PMID:Tumor rejection antigens on BALB3T3 cells transformed by activated oncogenes. 191 13

Experimental systemic lupus erythematosus (SLE) can be induced in mice by immunization with either a human monoclonal anti-DNA antibody bearing the 16/6 idiotype (16/6 Id) or with a mouse monoclonal anti-idiotypic antibody specific for the 16/6 Id. Susceptibility to the induction of experimental SLE is genetically determined but is not linked to the MHC. In the present study we tested the susceptibility of BM chimeras of different donor-host combinations to the induction of SLE and found that high levels of anti-16/6 Id and anti-ssDNA antibodies were induced in BALB/c-->C57BL/6, BALB/c-->BALB/c and normal BALB/c mice as opposed to C57BL/6-->BALB/c chimeras and normal C57BL/6 mice. The low levels of the anti-16/6 Id and anti-ssDNA antibodies produced by C57BL/6-->BALB/c chimeras immunized with the 16/6 fully allogeneic BMT as such chimeras were shown to produce high levels of antibodies to a T cell-dependent antigen (the synthetic polypeptide (Phe,G)-A--L). These results demonstrate that the production of SLE-related autoantibodies is controlled by donor-type BM derived cells and not by host-type cells in the thymic stroma.
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PMID:Systemic lupus erythematosus-related autoantibody production in mice is determined by bone marrow-derived cells. 824 73

(1) The polymerase chain reaction (PCR) was used to amplify Rh-related cDNAs from erythroid cells cultured by the selective two-phase liquid culture system for human erythroid progenitors in peripheral blood. Two Rh polypeptide cDNAs have been isolated from the PCR products and tentatively designated RhPI cDNA and RhPII cDNA. Both cDNA clones have an open reading frame composed of 1251 nucleotides. The RhPI cDNA clone shows a single nucleotide substitution with no amino acid substitution compared with the published sequence. The RhPII cDNA clone differs from the above by 41 nucleotide substitutions in the open reading frame, resulting in 31 amino acid substitutions. Besides these cDNA clones, eleven and five truncated isoforms of the RhPI and RhPII cDNAs, have been isolated, respectively. (2) The promoter region of the Duffy gene was cloned by IPCR of 1.1 kb SacI fragment and the 3' flanking sequence was cloned by IPCR of 1.9 kb EcoRI fragment. The IPCR products contained the known Duffy cDNA sequence without introns. By comparing the coding area of the Duffy gene in 28 Duffy positive individuals, we elucidated that one base change that results in an amino acid substitution (GAT(Asp44)-->GGT(Gly)) is in accordance with the Fya/Fyb polymorphism. This fact proves that the Duffy cDNA and its gene encode the Duffy blood group system. (3) Two common alleles in Esterase D (EsD) polymorphism, EsD1 and EsD2 were characterized by the substitution of one amino acid (Gly-Glu) caused by the point mutation of one nucleotide (G-A). The point mutation between cDNAs of EsD1 and EsD2 alleles was detectable as restriction fragment length polymorphism (RFLP) using Ssp1. The RFLP makes it possible to determine the EsD phenotypes using DNA samples from forensic materials without EsD enzymatic activity. (4) The authors report studies on 19 pairs of donors and recipients in bone marrow transplantation. A broad range of genetic markers at 42 gene loci, including one DNA marker 11 red blood cell markers, five human lymphocyte antigen types, 12 serum protein markers, five red cell enzyme markers, and eight salivary markers was evaluated before and after BMT over about 2 months. As a result, 11 out of 42 gene loci of genetic markers in recipients were transformed into the donor type.
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PMID:Molecular genetic basis of red cell markers and its forensic application. 869 Mar 20

Coumarins are main active components of Peucedanum praeruptorum Dunn. Among them, methoxylated coumarin compound, such as bergapten, xanthotoxin, and isopimpinellin, has high officinal value and plays an important role in medicinal field. However, major issues associated with the biosynthesis mechanism of coumarins remain unsolved and no corresponding enzyme has been cloned from P. praeruptorum. In this study, a local BLASTN program was conducted to find the candidate genes from P. praeruptorum transcriptome database using the nucleotide sequence of Ammi majus bergaptol O-methyltransferase (AmBMT, GenBank accession No: AY443006) as a template. As a result, a 1335 bp full-length of cDNA sequence which contains an open reading frame of 1080 bp encoding a BMT polypeptide of 359 amino acids was obtained. The recombinant protein was functionally expressed in Escherichia coli and displayed an observed activity to bergaptol. In vitro experiments show that the protein has narrow substrate specificity for bergaptol. Expression profile indicated that the cloned gene had a higher expression level in roots and can be induced by methyl jasmonate (MeJA). Subcellular localization analysis showed that the BMT protein was located in cytoplasm in planta. Homology modeling and docking based site-directed mutagenesis have been employed to investigate the amino acid residues in BMT required for substrate binding and catalysis. Conservative amino acid substitutions at residue H264 affected BMT catalysis, whereas substitutions at residues F171, M175, D226, and L312 affected substrate binding. The systemic study summarized here will enlarge our knowledge on OMTs and provide useful information in investigating the coumarins biosynthesis mechanism in P. praeruptorum.
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PMID:Cloning, Functional Characterization, and Catalytic Mechanism of a Bergaptol O-Methyltransferase from Peucedanum praeruptorum Dunn. 2725 33