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Biomedical subjects

A Tanoue

Publications and source records attributed to A Tanoue.

30 records · Page 2Linked to original sources
PubMed1991

Molecular defect in siblings with prolidase deficiency and absence or presence of clinical symptoms. A 0.8-kb deletion with breakpoints at the short, direct repeat in the PEPD gene and synthesis of abnormal messenger RNA and inactive polypeptide.

Prolidase deficiency is an autosomal recessive disorder with highly variable symptoms, including mental retardation, skin lesions, and abnormalities of collagenous tissues. In Japanese female siblings with polypeptide negative prolidase deficiency, and with different degrees of severity of skin lesions, we noted an abnormal mRNA with skipping of 192 bp sequence corresponding to exon 14 in lymphoblastoid cells taken from these patients. Transfection and expression analyses using the mutant prolidase cDNA revealed that a mutant protein translated from the abnormal mRNA had an Mr of 49,000 and was enzymatically inactive. A 774-bp deletion, including exon 14 was noted in the prolidase gene. The deletion had termini within short, direct repeats ranging in size of 7 bp (CCACCCT). The "slipped mispairing" mechanism may predominate in the generation of the deletion at this locus. This mutation caused a 192-bp in-frame deletion of prolidase mRNA and was inherited from the consanguineous parents. The same mutation caused a different degree of clinical phenotype of prolidase deficiency in this family, therefore factor(s) not related to the PEPD gene product also contribute to development of the clinical symptoms. Identification of mutations in the PEPD gene from subjects with prolidase deficiency provides further insight into the physiological role and structure-function relationship of this biologically important enzyme.

Amino Acid Sequence↗
PubMed1990

Structural organization of the gene for human prolidase (peptidase D) and demonstration of a partial gene deletion in a patient with prolidase deficiency.

Prolidase (peptidase D) catalyzes hydrolysis of the di- and tripeptide with carboxyl-terminal proline and plays an important role in recycling proline in various cells and tissues. By using human prolidase cDNA as a probe, a chromosomal gene related to prolidase was isolated from human gene libraries. The human prolidase gene is over 130 kilobases long and is split into 15 exons. All of the splice donor and acceptor sites conform to the GT/AG rule. The transcription initiation site was determined by nuclease S1 mapping and primer extension and was located 131 bases upstream from the initiation codon. A "CAAT" box-like sequence was present 67 bases upstream from the cap site, but there was no "TATA" box-like sequence. There were seven sets of sequences resembling the transcription factor Sp1 binding sites. Four were upstream from the cap site, and three were downstream. We also analyzed findings in patients with prolidase deficiency with respect to major gene re-arrangement. Several hundred base deletions, including the 14th exon, were identified. Knowledge of the gene structure of human prolidase will facilitate further studies on the expression and regulation of this gene and provide necessary information for analyses of mutations in patients with this deficiency.

Base Sequence↗
PubMed1990

Electron microscope autoradiographic examination of uptake behavior of lipophilic chemicals into fish gill.

Juvenile carp (Cyprinus carpio) were exposed to fenvalerate and to an oligomer with molecular weights of 420 and 2,000-50,000 and log Po/w values of 6.4 and more than 14, respectively, and uptake behavior into gill tissues was observed by electron microscope autoradiography. It was qualitatively demonstrated that fenvalerate was absorbed into gill tissues and localized in membrane systems of each cell. On the other hand, no absorption was observed for the oligomer, even in the external membrane of pavement cells. These results suggest that absorption of the oligomer is limited by low diffusion into membranes due to its very high molecular weight, resulting in no bioconcentration in fish. The significance of log Po/w in uptake behavior is also verified from the distribution behavior of fenvalerate.

Animals↗
PubMed1990

Biochemical basis of prolidase deficiency. Polypeptide and RNA phenotypes and the relation to clinical phenotypes.

Cultured skin fibroblasts or lymphoblastoid cells from eight patients with clinical symptoms of prolidase deficiency were analyzed in terms of enzyme activity, presence of material crossreacting with specific antibodies, biosynthesis of the polypeptide, and mRNA corresponding to the enzyme. There are at least two enzymes that hydrolyze imidodipeptides in these cells and these two enzymes could be separated by an immunochemical procedure. The specific assay for prolidase showed that the enzyme activity was virtually absent in six cell strains and was markedly reduced in two (less than 3% of controls). The activities of the labile enzyme that did not immunoprecipitate with the anti-prolidase antibody were decreased in the cells (30-60% of controls). Cell strains with residual activities of prolidase had immunological polypeptides crossreacting with a Mr 56,000, similar to findings in the normal enzyme. The polypeptide biosynthesis in these cells and the controls was similar. Northern blot analyses revealed the presence of mRNA in the polypeptide-positive cells, yet it was absent in the polypeptide-negative cells. The substrate specificities analyzed in the partially purified enzymes from the polypeptide-positive cell strains differed, presumably due to different mutations. Thus, there seems to be a molecular heterogeneity in prolidase deficiency. There was no apparent relation between the clinical symptoms and the biochemical phenotypes, except that mental retardation was present in the polypeptide-negative patients. The activities of the labile enzyme may not be a major factor in modifying the clinical symptoms.

Adolescent↗
PubMed1990

A single nucleotide change in the prolidase gene in fibroblasts from two patients with polypeptide positive prolidase deficiency. Expression of the mutant enzyme in NIH 3T3 cells.

Prolidase deficiency is an autosomal recessive disorder characterized by mental retardation and various skin lesions. Cultured skin fibroblasts were obtained from two independent patients with abnormal prolidase. Using the polymerase chain reaction, we amplified the entire coding region of human prolidase mRNA derived from patients' fibroblasts. Nucleotide sequence analysis of amplified cDNA products revealed a G to A substitution at position 826 in exon 12, where aspartic acid was replaced by asparagine at the amino acid residue 276, in cells from both patients. An analysis of the DNA showed that the substitution was homozygous. An expression plasmid clone containing a normal human prolidase cDNA (pEPD-W) or mutant prolidase cDNA (pEPD-M) was prepared, transfected, and tested for expression in NIH 3T3 cells. Incorporation of pEPD-W and pEPD-M resulted in the synthesis of an immunological polypeptide that corresponded to human prolidase. Active human enzyme was detected in cells transfected with pEPD-W, but not in those transfected with pEPD-M. These results were compatible with our observation of fibroblasts and confirmed that the substitution was responsible for the enzyme deficiency. As active prolidase was recovered in prolidase-deficient fibroblasts transfected with pEPD-W, this restoration of prolidase activity after transfection means that gene replacement therapy for individuals with this human disorder can be given due consideration.

Animals↗
PubMed1989

Primary structure and gene localization of human prolidase.

Complementary DNA clones of prolidase (imidodipeptidase, EC 3.4.13.9) were isolated from human liver and placental cDNA libraries. Two clones named lambda PL21 and lambda PP6 from the liver and placental cDNA libraries, respectively, were analyzed in detail. The first clone, lambda PL21, carried a cDNA insert of 1.7 kilobase pairs and covered all the coding region of human prolidase mRNA. The second clone, lambda PP6, contained a 1.8-kilobase insert with a full-length 3'-untranslated region. Comparison of the amino acid sequence predicted from the nucleotide sequence of the cDNA insert of the two clones with the partial amino acid sequence determined by Edman degradation of peptides derived from human erythrocyte prolidase established that both clones code for human prolidase. The amino terminus of the human mature enzyme is blocked and seems to begin with the sequence X-Ala-Ala-Ala. Presumably no processing occurs at the carboxyl terminus. The mature enzyme is composed of 492 residues, corresponding to Mr 54,305. The sequence of prolidase is unique and not similar to any known protein, except for a significant similarity to regions of F1-ATPase alpha and beta subunits from various sources. The gene has been mapped to the short arm of chromosome 19 (19p13.2). Elucidation of the complete amino acid sequence and the gene location of prolidase should provide the basis for understanding structure-function relationships and also inherited disorders caused by deficiency of this metabolically important enzyme.

Amino Acid Sequence↗
PubMed1988

Immunoaffinity purification of human erythrocyte prolidase.

A procedure including immunoaffinity gel chromatography of an immobilized monoclonal antibody was used to isolate human erythrocyte prolidase (EC 3.4.13.9). The monoclonal antibody was developed against liver prolidase and the antibody recognized the erythrocyte enzyme. The purification procedure included three steps of DEAE cellulose (batcher), immunoaffinity gel chromatography and gel filtration column chromatography. The overall recovery was approximately 20% and the specific activity of the purified preparation was approximately 260 U/mg of protein, a value exceeding that obtained using conventional procedures.

Chromatography, Affinity↗
PubMed1984

Clinical efficacy, extrapyramidal symptoms and serum levels: influence of administration schedules and concomitant drugs on serum bromperidol concentrations.

Bromperidol (4 or 12 mg per day) was administered to 18 newly admitted schizophrenics and 29 chronic schizophrenic inpatients once or four times a day and the two dose schedules were compared. The bromperidol levels in the four-times-a-day group were significantly higher than those in the once-a-day group and the daily variation in the serum level of the agent was markedly wider in the latter than in the former patients. The incidence and severity of extrapyramidal symptoms were not significantly different between the two. A clear relationship was not present between the serum levels and the development of extrapyramidal symptoms. The bromperidol serum values were not correlated with the therapeutic response but, at more than 5 ng per ml, there might be a positive correlation between the bromperidol levels and clinical efficacy in the newly admitted schizophrenics. As for concomitant medication, levomepromazine may raise the bromperidol serum level. An anti-parkinson drug failed to depress the bromperidol level.

Adult↗