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1.
In the process of molecular cloning of cDNA for proteins associated with a purified human placental sialidase fraction, we discovered one of the proteins with apparent molecular weight of 46 kDa is in reality alpha-N-acetylgalactosaminidase. The full length cDNA, pcD-HS1204, codes for 358 amino acids with the first 17 residues representing a putative signal peptide. The predicted amino acid sequence shows striking homology with human alpha-galactosidase A and yeast alpha-galactosidase. The substrate specificities as well as the behavior of the 46 kDa protein on hydroxylapatite chromatography confirmed that the 46 kDa protein is in reality alpha-N-acetylgalactosaminidase.  相似文献   

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Molecular cloning and characterization of cDNA for human myeloperoxidase   总被引:8,自引:0,他引:8  
Partial amino acid sequence of human myeloperoxidase was determined, and a 41-base oligonucleotide containing deoxyinosines at four positions was chemically synthesized. By using the oligonucleotide as a probe, cDNA clones for human myeloperoxidase were isolated from a cDNA library constructed with mRNA from human promyelocytic leukemia HL-60 cells. One of the clones containing a 2.6-kilobase insert was subjected to nucleotide sequence analysis. The sequence was found to contain an open reading frame, 2,235 nucleotides coding for a protein of 745 amino acids with a calculated Mr of 83,868. The heavy chain of myeloperoxidase, consisting of 467 amino acids, was located on the COOH terminus half of the protein. The RNA specified by the cDNA was prepared using SP6 RNA polymerase and translated in rabbit reticulocyte lysates, and the product was identified as human myeloperoxidase by immunoprecipitation with rabbit anti-human myeloperoxidase antibody. By Northern hybridization analysis of RNA from leukemic cells, it was shown that myeloperoxidase mRNA is abundantly expressed in human promyelocytic HL-60 and mouse myeloid leukemia NFS-60 cells. Furthermore, the results of Southern hybridization analysis of human genomic DNA suggest that there are one or two genes for myeloperoxidase in the human haploid genome.  相似文献   

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Four overlapping cDNA clones encoding contrapsin were isolated from a mouse liver cDNA library constructed in the expression vector, lambda gt11. M13 vector sequence analysis revealed that contrapsin cDNA contained an open reading frame of 1,254 bases encoding 418 amino acids. The N-terminal amino acid sequence of the isolated contrapsin matched residues 30 to 48 of the sequence deduced on nucleotide analysis. One clone, which had the longest 3' untranslated region, contained two sets of tandem polyadenylation signals, AATACA and AATAAA, which were located 497 bases apart, while the remaining three clones terminated at the first signal. The entire reading frame sequence of contrapsin cDNA showed 64% homology with that of human alpha-1-antichymotrypsin.  相似文献   

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A full-length cDNA clone of the human pregnancy zone protein (PZP) was cloned from the hepatocellular carcinoma cell line Hep3B. Based on the exon sequences of the PZP gene (Devriendt et al. (1989) Gene 81, 325-334; Marynen et al., unpublished data), primer pairs were designed to amplify six overlapping fragments of the PZP cDNA. The obtained cDNA is 4609 bp long and contains an open reading frame coding for 1482 amino acids, including a signal peptide of 25 amino acid residues. Comparison with the published partial PZP amino acid sequence (Sottrup-Jensen et al. (1984) Proc. Natl. Acad. Sci. USA 81, 7353-7357) and the PZP genomic sequences confirmed the identity as a PZP cDNA. 71% of the corresponding amino acid residues in PZP and human alpha 2-macroglobulin (alpha 2M) are identical and all cysteine residues are conserved. A typical internal thiol ester site and a bait domain were identified. A Pro/Thr polymorphism was identified at amino acid position 1180, and an A/G nucleotide polymorphism at bp 4097.  相似文献   

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Eucaryotes contain a class of enzymes called flavin-dependent monooxygenases (FMOs). Unlike mammals, yeast have only a single isoform-yFMO. Deletion mutants suggested that yFMO may play a role in folding proteins which contain disulfide bonds. Recently we detected two nucleotide errors in the GenBank sequences attributed to the yFMO gene. This previously led us to express and characterize a 373-residue catalytically active protein instead of the correct 432-residue enzyme. Here we report the sequencing, expression, and enzyme characterization of the full-length form of yFMO. Comparison of the two forms of yFMO showed similar pH profiles and K(m), K(cat), and V(max) values using glutathione as a substrate. These results indicate that the full-length yeast FMO has biochemical and catalytic properties similar to those of the truncated protein. Therefore, it is likely that the hypotheses concerning the enzyme's function proposed earlier are still valid.  相似文献   

10.
Molecular cloning of a cDNA for human delta-aminolevulinate dehydratase   总被引:5,自引:0,他引:5  
A cDNA encoding human delta-aminolevulinic acid dehydratase (ALA-D; EC 4.2.1.24), the second enzyme in the heme biosynthetic pathway, was isolated from a human liver cDNA expression library. Of the original 17 clones selected with anti-ALA-D antibody, only four expressed anti-ALA-D epitopes as assessed by rescreening with antibody preabsorbed with purified antigen. Subsequent screening of the antibody-positive clones with mixed oligodeoxynucleotide (oligo) probes, synthesized to correspond to human N-terminal and bovine active-site peptide sequences, identified three clones which hybridized only with the oligo probes for the bovine amino acid (aa) sequences. Restriction endonucleases analysis revealed that these three clones contained the same 800-bp cDNA insert. This insert was recloned into bacteriophage M13mp18 and mp19 and sequenced by primer extension. The aa sequence predicted from the partial nucleotide sequence was found to be essentially colinear with the sequences of four bovine ALA-D peptides, totaling 35 non-overlapping aa residues.  相似文献   

11.
A cDNA clone coding for the cell attachment domain in human fibronectin has been isolated using synthetic oligonucleotides. Three sets of mixed tetradecamer oligonucleotides were synthesized based on amino acid sequences in the 108-amino acid cell attachment domain (Pierschbacher, M. D., Ruoslahti, E., Sundelin, J., Lind, P., and Peterson, P. A. (1982) J. Biol. Chem. 257, 9593-9597). One of these sets was made complementary to amino acids located near the COOH terminus of the cell attachment domain and synthesized as a mixture of 24 sequences. This oligonucleotide mixture was used to prime cDNA synthesis with mRNA prepared from a human fibrosarcoma as a template. A cDNA library was constructed with the oligonucleotide-primed sequences in the vector pBR322. Colonies that hybridized with the primer were isolated from the library and further identified by hybridization with oligonucleotides deduced from an amino acid sequence located 45 amino acid residues NH2-terminal of the primer sequence. One clone which hybridized to both probes was characterized in detail. The insert was 380 base pairs long and its nucleotide sequence agreed completely with the corresponding amino acid sequence of human plasma fibronectin, showing that the sequences for this region are identical in plasma fibronectin and fibronectin from a cell line. This clone should be useful for studies on the expression of fibronectins and may also allow for the production of the biologically active cell attachment domain of fibronectin in bacteria.  相似文献   

12.
A nearly full-length cDNA clone for catalase (pCAS01) was obtained through immunological screening of cDNA expression library constructed from size-fractionated poly(A)-rich RNA of wounded sweet potato tuberous roots by Escherichia coli expression vector-primed cDNA synthesis. Two additional catalase cDNA clones (pCAS10 and pCAS13), which contained cDNA inserts slightly longer than that of pCAS01 at their 5'-termini, were identified by colony hybridization of another cDNA library. Those three catalase cDNAs contained primary structures not identical, but closely related, to one another based on their restriction enzyme and RNase cleavage mapping analyses, suggesting that microheterogeneity exists in catalase mRNAs. The cDNA insert of pCAS13 carried the entire catalase coding capacity, since the RNA transcribed in vitro from the cDNA under the SP6 phage promoter directed the synthesis of a catalase polypeptide in the wheat germ in vitro translation assay. The nucleotide sequencing of these catalase cDNAs indicated that 1900-base catalase mRNA contained a coding region of 1476 bases. The amino acid sequence of sweet potato catalase deduced from the nucleotide sequence was 35 amino acids shorter than rat liver catalase [Furuta, S., Hayashi, H., Hijikata, M., Miyazawa, S., Osumi, T. & Hashimoto, T. (1986) Proc. Natl Acad. Sci. USA 83, 313-317]. Although these two sequences showed only 38% homology, the sequences around the amino acid residues implicated in catalytic function, heme ligand or heme contact had been well conserved during evolution.  相似文献   

13.
We cloned a full-length complementary DNA for the hemagglutinin-neuraminidase (HN) mRNA of Sendai virus (HVJ) using a synthetic 27-mer as a probe. Nucleotide sequence analysis showed that there is a long open reading frame on the mRNA that encodes a protein of 575 amino acids. The deduced amino acid sequence indicated that only one hydrophobic region sufficiently long to anchor the protein in the membrane and located near the N-terminus (amino acids 35-60). It is suggested that HN protein is oriented with its N-terminus inside the membrane.  相似文献   

14.
A cDNA library from rat brain was constructed in pBR322 and screened with a 14-mer mixed oligonucleotide probe based on residues 231-235 of bovine proteolipid (PLP). A positive clone was isolated: it contained a 1334-base-pair cDNA insert and was subjected to DNA sequence analysis. The cDNA encoded information for the 276 amino acids of rat PLP. Comparison with bovine PLP sequence showed a complete amino acid sequence homology except for 4 amino acid residues.  相似文献   

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Summary Complementary DNA-clones for human preproacrosin have been isolated from a human testis cDNA library in gt11. The nucleotide sequence of the 1402bp cDNA insert includes a 20 bp 5 noncoding region, an open reading frame of 1263bp corresponding to 421 amino acids (45.9 kdalton), and a 105 bp 3 untranslated region. The deduced amino acid sequence is compared with that recently evaluated from a cDNA clone for boar preproacrosin. The sequence identity is 70%; the leader sequence, the catalytic triad (His, Asp, Ser; which is characteristic for serine proteinases) and the positions of the cysteine residues crosslinking the light and the heavy chain of the active enzyme, acrosin, are conserved in both species. At the C-terminal end, a proline-rich sequence is present in both species; this may represent the species-specificity of acrosin.  相似文献   

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The nucleotide sequence data reported in this paper have been submitted to the GenBank sequence database and have been assigned the accession number L33910  相似文献   

19.
Summary A full-length, low-molecular-weight (LMW) glutenin cDNA clone, pTdUCD1, has been isolated from a Triticum durum cv Mexicali wheat cDNA library. The complete sequence was determined and compared to the LMW glutenin genes that have been isolated from hexaploid wheat, Triticum aestivum. This cDNA codes for a protein of 295 amino acids (33,414 daltons) including a 20-amino acid signal peptide as deduced from the DNA sequence. Northern analysis showed that this cDNA hybridizes to a family of related sequences ranging in length from 1,200 to 1,000 nucleotides. This gene is similar but not identical to previously published LMW glutenin gene sequences. The most striking characteristic of all cloned LMW glutenin genes is the conservation of eight cysteine residues, which could be involved in potential secondary or tertiary structure, disulfide bond interactions. This paper presents a structural map defining distinct regions of the LMW glutenin gene family.  相似文献   

20.
Molecular cloning of cDNA coding for human preprourokinase   总被引:2,自引:0,他引:2  
A cDNA library was constructed in pBR322 from 18S to 20S mRNA that was extracted from human kidney cells, fractionated on oligo(dT)-cellulose column and sucrose-density gradient, and confirmed for urokinase production in Xenopus laevis oocytes. The Escherichia coli RR1 transformants were hybridized to synthetic oligonucleotide probe prepared according to the known amino acid sequence, Glu 73 to Glu 77 of human urinary urokinase chain B. The entire cloned cDNA covers a 2250-bp region, wherein the 1293-bp sequence codes for preprourokinase consisting of 431 amino acids, with the first 20 residues being a signal peptide. The 5'-untranslated region is at least 80 bp long and the 3'-untranslated region is longer than 850 bp.  相似文献   

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