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Biomedical subjects

I Sakai

Publications and source records attributed to I Sakai.

At least 73 records · Page 4Linked to original sources
PubMed1989

Characterization of four different mammalian-cell-derived recombinant human interferon-beta 1s. Identical polypeptides and non-identical carbohydrate moieties compared to natural ones.

In order to evaluate the structural identification of various recombinant human interferon-beta 1s, the recombinant proteins were produced in four different mammalian cells (human PC12 and PC8 lung adenocarcinoma cells, Chinese hamster ovary cells and mouse C127 cells) and characterized. Each mammalian-cell-derived recombinant human interferon-beta 1 represented a single band of 23 kDa on sodium dodecyl sulphate/polyacrylamide gel electrophoresis, the same molecular mass as fibroblast-derived natural human interferon-beta 1. Specific activities, amino acid compositions, amino-terminal sequences, peptide maps on C18 reversed-phase high-performance liquid chromatography and circular dichroic spectra of recombinant proteins were in good agreement with natural ones. On the other hand, the patterns of isoelectric focusing were different between mammalian-cell-derived recombinant human interferon-beta 1s and natural human interferon-beta 1. Sugar composition analysis revealed that the recombinant protein from Chinese hamster ovary cells has a similar sugar composition to that of natural protein and the other recombinant proteins have increased amounts of galactose and glucosamine in comparison to the natural protein. Furthermore, there is no galactosamine in the natural protein, while small amounts of galactosamine were detected in the oligosaccharides released from PC8- and C127-derived recombinant proteins by N-glycanase. These results indicate that mammalian-cell-derived recombinant human interferon-beta 1s have identical polypeptides to those of natural human interferon-beta 1 but their carbohydrate moieties, including unusual N-linked oligosaccharides, are individually different from natural ones and depend on the host cell.

Adenocarcinoma↗
PubMed1989

[Association of immunomodulators and HLA antigens in rheumatoid arthritis].

We studied the association between HLA antigens and clinical response to immunomodulators or the toxic effects of immunomodulators in 191 patients with rheumatoid arthritis (RA). All patients received nonsteroidal anti-inflammatory drugs. Fifty-seven patients were treated with auranofin, 61 patients with penicillamine and 45 patients with lobenzarit. We found that HLA-Cw 1 is significantly (p less than 0.05) associated with a substantial clinical response to auranofin in RA patients (65% vs 33% of Cw 1-negative patients). We observed that HLA-DR 4 is a risk factor for the occurrence of toxic reactions to penicillamine (45% vs 21% of DR 4-negative patients: p less than 0.05) and that HLA-DRw 9 is a risk factor in the case of lobenzarit (62% vs 32% of DRw 9-negative patients: p less than 0.05). HLA-A 24-positive patients with RA experienced a low frequency of side effects from auranofin (16% vs 37% of A 24-negative patients: p less than 0.05). HLA-A 2 or Cw 7-positive patients with RA experienced a low frequency of side effects from penicillamine (12% vs 49% of A 2-negative patients: p less than 0.01, 17% vs 46% of Cw 7-negative patients: p less than 0.05). Our data demonstrated that HLA antigens are significantly associated with a clinical response to immunomodulators and the toxic effects of immunomodulators in patients with RA.

Adjuvants, Immunologic↗
PubMed1987

The cDNA and protein sequences of human lactate dehydrogenase B.

Human lactate dehydrogenase B (LDH-B) cDNA was isolated and sequenced. The LDH-B cDNA insert consists of the protein-coding sequence (999 bp), the 5' (54 bp) and 3' (203 bp) non-coding regions, and the poly(A) tail (50 bp). The predicted sequence of 333 amino acid residues was confirmed by amino acid composition and/or sequence analyses of a total of 185 (56%) residues from tryptic peptides of human LDH-B protein. The nucleotide and amino acid sequences of the human LDH-B coding region show 68% and 75% homologies respectively with those of the human LDH-A. The peptide map and amino acid composition data have been deposited as Supplementary Publication SUP 50139 (7 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies are available on prepayment [see Biochem. J. (1987) 241, 5].

Amino Acid Sequence↗
PubMed1987

Expression of the cDNA encoding for mouse sperm-specific lactate dehydrogenase C in Chinese-hamster ovary cells.

The cloned cDNA encoding for mouse sperm-specific lactate dehydrogenase C (LDH-C) was inserted immediately downstream to the MMTV 5' LTR promoter, and it was shown to synthesize mouse LDH-C polypeptide in Chinese-hamster ovary cells. The mouse LDH-C subunit and the endogenous Chinese-hamster LDH-A subunit formed in vivo a heterotetrameric LDH-A3C1 isoenzyme, and this novel isoenzyme exhibited enzymic activity utilizing lactate as substrate.

Animals↗
PubMed1987

Molecular cloning and nucleotide sequence of the cDNA for sperm-specific lactate dehydrogenase-C from mouse.

Mouse sperm-specific lactate dehydrogenase-C (LDH-C) cDNA was cloned and sequenced from lambda gt11 expression library. The LDH-C cDNA insert of 1236 bp consists of the protein-coding sequence (999 bp), the 5' (54 bp) and 3' (113 bp) non-coding regions, and the poly(A) tail (70 bp). The Northern blot analysis of poly(A)-containing RNAs from mouse testes and liver indicates that the LDH-C gene is expressed in testes but not in liver, and that its mRNA is approx. 1400 nucleotides in length. The nucleotide and amino acid sequences of the mouse LDH-C cDNA show 73% and 72% homologies, respectively, with those of the mouse LDH-A. The Southern blot analysis of genomic DNAs from mouse liver and human placenta indicates the presence of multiple LDH-C gene-related sequences.

Amino Acid Sequence↗
PubMed1987

Molecular nature of spontaneous mutations in mouse lactate dehydrogenase-A processed pseudogenes.

The presence of at least ten mouse LDH-A pseudogenes was demonstrated in the genomic blot analysis, and four different processed pseudogenes have thus far been isolated and characterized. In this report, the nucleotide sequences to two different mouse lactate dehydrogenase-A processed pseudogenes, M11 and M14, were determined and compared with the protein-coding sequences of the mouse and rat LDH-A functional genes. In the pseudogene M11, the sequence of 64 nucleotides from codon no. 257 to 278 was tandemly duplicated. In the pseudogene M14, the sequence of 22 nucleotides from codon no. 68 to 75 was replaced by an inserted repetitive sequence of 242 nucleotides homologous to a mouse truncated R element. The pattern of nucleotide substitutions accumulated in mouse LDH-A pseudogenes M11 and M14, as well as that of pseudogene M10 identified previously, was analyzed, and the substitution frequencies of the C or G at the CG dinucleotide were found to be high.

Animals↗
PubMed1984

Lewis-like activities of and rabbit antisera against glycoconjugates present in edible organs of phanerogamia and cryptogamia.

13 species of phanerogamia and cryptogamia were found to contain substances cross-reacting with anti-Lewis agglutinins in ethanol precipitates from their edible organs such as leaves. Crude glycoconjugates were isolated from some species by Sephacryl S-200 gel filtration, immunization with some of which resulted in the production in rabbits of anti-Lea-like agglutinins with a high titer. Production of anti-Lea-like precipitin with high specificity was also confirmed in a rabbit antiserum against the glycoconjugate prepared from young leaves of Aralia elata.

Animals↗
PubMed1982

[Studies on tubercle bacilli and their contaminant bacteria in the sputum of pulmonary tuberculosis after chemotherapy ].

Growth activity and morphological changes of tubercle bacilli under prolonged chemotherapy were examined in the sputa of patients with pulmonary tuberculosis. Special attention was paid to the growth activity and pathogenicity of smear-positive and culture-negative bacilli. In addition, the incidence of tubercle bacilli and contaminant bacteria in the sputa was also followed during the prolonged chemotherapy. 1) One case out of about 70 patients with pulmonary tuberculosis showed persistent smear-positive and culture-negative bacilli in the sputa over a period of 15 month. The bacilli were successfully cultured on the Kirchner medium fortified with calf sera. The harvested bacilli were injected into guinea pig for their pathogenicity. However, no macroscopic changes were observed with the tuberculin test remaining negative. 2) Tubercle bacilli disappeared from the sputa of most patients who had received chemotherapy over a period ranging from several weeks to month. Contaminant bacteria were usually recovered from sputa containing less tubercle bacilli. In sputa rich in tubercle bacilli contaminant bacteria were sparse, but as the tubercle bacilli decreased by chemotherapy, so increased reciprocally the bacteria which were shown to be resistant to anti-tuberculosis drugs used.

Animals↗
PubMed1981

Composition and immunochemical properties of glycoproteins with anti-B agglutinin activity isolated from Euonymus sieboldiana seeds.

Five major glycoproteins with anti-B agglutinin activity were isolated from seeds of Euonymus Sieboldiana by a procedure based on precipitation with ammonium sulphate, Sepharose 4B gel filtration, CM- and DEAE-Sepharose chromatography and Sephacryl S-200 gel filtration. The purified glycoproteins each gave a single symmetrical peak on Sephacryl S-200 gel filtration with elution volumes corresponding to molecular weights of approximately 15,000 to 130,000, each forming a single precipitin line on gel diffusion plates with anti-E. Sieboldiana antibody. These anti-B glycoproteins were rich in acidic amino acids without cysteine and methionine and contained about 8--36% carbohydrate, of which galactose, arabinose and glucose were the predominant sugars, with small amounts of glucosamine, rhamnose, fucose, xylose, mannose and ribose. The most anti-B active lectin agglutinated human B red blood cells at a concentration of 2 micrograms/ml and was strongly inhibited by melibiose. The three other lectins with anti-B agglutinin activity, however, were not inhibited by any galactose-containing glycosides.

ABO Blood-Group System↗
PubMed1981

Purification, composition and immunochemical properties of arabinogalactan-protein H active glycopeptides from Euonymus sieboldiana seeds.

Seven blood group H active glycopeptides were isolated from the defatted seeds of Euonymus Sieboldiana by a procedure that included extraction with cold phosphate-buffered saline, fractionation with ammonium sulfate, chromatography with CM- and DEAE Sepharose CL 6B, and gel filtration on Sepharose 4B and Sephacryl S-200. Each glycopeptide, except three macromolecular ones, eluted as a single symmetrical peak from the Sephacryl S-200 chromatography. On the basis of their elution from a column that had been calibrated with FITC-dextrans as molecular weight markers, these glycopeptides had molecular weights of approximately 110,000, 15,000 and 8,000. All isolated H active glycopeptides inhibited eel anti-H reagent at concentrations of 1 to 63 microgram/ml and exhibited a single precipitation band against the eel reagent on immunodiffusion. Furthermore, all of them contained galactose and arabinose as major sugars, with fucose, rhamnose, mannose, glucose and glucosamine as minor sugars. Amino acid analysis of the four H active glycopeptides retarded by the Sepharose 4B column revealed the presence of hydroxyproline together with large amounts of threonine and serine. However, the three excluded macromolecular H active glycopeptides contained both threonine and serine, but no hydroxyproline.

ABO Blood-Group System↗