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C Valentin

Publications and source records attributed to C Valentin.

At least 19 recordsLinked to original sources
PubMed1992

Compound heterozygosity in a complete erythrocyte bisphosphoglycerate mutase deficiency.

Erythrocyte bisphosphoglycerate mutase (BPGM) deficiency is a rare disease associated with a decrease in 2,3-diphosphoglycerate concentration. A complete BPGM deficiency was described in 1978 by Rosa et al (J Clin Invest 62:907, 1978) and was shown to be associated with 30% to 50% of an inactive enzyme detectable by specific antibodies and resulting from an 89 Arg-->Cys substitution. The propositus' three sisters exhibited the same phenotype, while his two children had an intermediate phenotype. Samples from the family were examined using polymerase chain reaction and allele-specific oligonucleotide hybridization and sequencing techniques. Amplification of erythrocyte total RNA from the propositus' sister around the 89 mutation indicated the presence of two forms of messenger RNAs, a major form with the 89 Arg-->Cys mutation and a minor form with a normal sequence. Sequence studies of the propositus' DNA samples indicated heterozygosity at locus 89 and another heterozygosity with the deletion of nucleotide C 205 or C 206. Therefore, the total BPGM deficiency results from a genetic compound with one allele coding for an inactive enzyme (mutation BPGM Créteil I) and the other bearing a frameshift mutation (mutation BPGM Créteil II). Examination of the propositus' two children indicated that they both inherited the BPGM Créteil I mutation.

Arginine↗
PubMed1990

Isolation and characterization of the gene encoding the muscle-specific isozyme of human phosphoglycerate mutase.

The human muscle-specific phosphoglycerate mutase encoding gene (PGAM-M) has been cloned from a genomic cosmid library and sequenced. The sequence corresponding to the coding region was evaluated and revised by sequencing of the protein itself, fully confirming our results. The amino acid sequence of the M isozyme presented a 80.6% homology with the B isozyme (non-muscle-specific isozyme), a value higher than previously reported. The PGAM-M gene is composed of three exons, which consist of 454, 180 and 202 bp, respectively, and are separated by two introns of 103 bp and approx. 5.6 kb, respectively. Comparison of the structure of the human PGAM-M gene with that coding for human bisphosphoglycerate mutase, an erythroid-specific enzyme belonging to the same multifunctional enzyme family, revealed that the location of the second intron is similar in each gene and corresponds to a tertiary subdomain in the spatial structure of the protein. The transcription start point (tsp) in the PGAM-M gene was identified by both primer extension and S1 nuclease-protection experiments. A TATA-box-like element was observed 29 bp upstream from the tsp; the sequence ATTGG, inverse/complementary to CCAAT-box, was found 40 bp upstream from the supposed TATA box. No muscle-specific consensus sequences could be detected in the 5'-untranslated region. Only one polyadenylation AATAAA signal was observed in the short 3'-untranslated region (43 bp long). Finally, only one copy of this gene is present in the human genome instead of the several copies found for the PGAM-B gene, suggesting the possible evolutionary origin of the muscle subunit in a modified copy of the PGAM-B gene.

Amino Acid Sequence↗
PubMed1990

In situ mapping of the muscle-specific form of phosphoglycerate mutase gene to human chromosome 7p12-7p13.

A 2.3-kb-long probe derived from the 5' flanking region, the first exon and part of the first intron of the human muscle-specific phosphoglycerate mutase gene (PGAM-M) (EC 5.4.2.1) was used to map the gene by "in situ" chromosomal hybridization. The structural gene for PGAM-M was assigned to chromosome 7p12-7p13; a single hybridization peak indicated that there is a single gene for this isozyme of PGAM, and confirmed results obtained by Southern blot hybridization.

Bisphosphoglycerate Mutase↗
PubMed1990

Molecular size characterization of bacterial capsular polysaccharide vaccines by high performance liquid chromatography.

Bacterial capsular polysaccharides are major virulence factors and some are used as vaccinal antigens. Their molecular size is an important physicochemical criterion which correlates with immunogenicity. This article describes a new application of high performance liquid chromatography (HPLC), based on molecular sieving, for such an evaluation. This HPLC method is rapid, accurate, reproducible, requires only very low amounts of product and presents good correlation with conventional gel permeation chromatography.

Bacterial Capsules↗
PubMed1988

Isolation and characterization of the human 2,3-bisphosphoglycerate mutase gene.

The human 2,3-bisphosphoglycerate mutase gene was isolated from genomic libraries and analyzed by Southern blots and DNA sequencing. The transcription initiation site was localized by primer extension as well as by S1 protection of the mRNA. The gene extends over 22 kilobase pairs; it is composed of two introns (8.8 and 11.5 kilobase pairs long) and three exons (84, 662, and 965 base pairs long). The second exon correlates with a functional subdomain of the protein, as shown by comparison with the yeast phosphoglycerate mutase structure. The sequence TAGAAAA was found 30 bases upstream from the transcription initiation site and could be analogous to the TATA box. A sequence homologous to the CCAAT box was found twice, at positions -75 and -178. There is no GC-rich sequence or GC box in the 5'-flanking region of the gene. Northern blot analysis indicates that the 2,3-bisphosphoglycerate mutase mRNA is detected mainly in erythroid tissues and cell lines, although it is also present in low amounts in a nonerythroid tissue. A comparison of the 5'-upstream sequences with other promoters active only in erythroid cells did not reveal any common signal that could be responsible for the "erythroid promoter."

Amino Acid Sequence↗
PubMed1987

Time-course of alterations of high density lipoproteins (HDL) during thyroxine administration to hypothyroid women.

Serum HDL cholesterol, apolipoproteins AI and AII and post heparin lipolytic activities (PHLA) have been measured in a group of fourteen hypothyroid women without ovarian oestrogen secretion before and during a 2-month thyroxine treatment. The more rapid and consistent observed event was a decrease in apo AI levels (164 +/- 5 vs. 149 +/- 5 mg dl-1, mean +/- SEM, P less than 0.05) correlated (r = 0.79, P less than 0.05) to a slight increment of PHLA. A slight decrease in apo AII concentration was seen only after 5 days (25 +/- 2 vs. 22 +/- 2 mg dl-1, P less than 0.05) and in HDL cholesterol only after 60 days (1.3 +/- 0.6 vs. 1.1 +/- 0.5 mmol 1-1, P less than 0.05). Apo AI, HDL2 and HDL3 cholesterol were measured in another group of seven hypothyroid postmenopausal women before and after a 2-month thyroxine treatment. We observed a decrease in HDL2 cholesterol (1.69 +/- 0.20 vs. 1.17 +/- 0.09 mmol 1-1, P less than 0.02) with no changes in HDL3 cholesterol (0.88 +/- 0.09 vs. 0.99 +/- 0.06 mmol 1-1, NS). The decrease in HDL2 cholesterol correlated (r = 0.72, P = 0.05) with that for apo AI. The differential influence of thyroxine (T4) administration on the major HDL components might reflect changes in HDL composition due to the multiple effects of thyroid hormones on lipid metabolism. It can be hypothesized that the decrease in apo AI and HDL2 cholesterol concentrations are due, at least in part, to the increase in hepatic lipase activity.

Adolescent↗
PubMed1987

Molecular cloning of the human 2,3-bisphosphoglycerate mutase cDNA and revised amino acid sequence.

The human erythrocyte 2,3-bisphosphoglycerate mutase (BPGM) is a multifunctional enzyme which controls the metabolism of 2,3-diphosphoglycerate (DPG), the main allosteric effector of haemoglobin. Several cDNA banks were constructed from reticulocyte mRNA either by conventional cloning methods in plasmid pBR322 and screening with specific mixed oligonucleotide probes, or in the expression vector lambda gt 11. The largest cDNA isolated was 1673 bases, and encodes for a protein of 258 amino acids; it contains a large 3' untranslated region (785 bases). It is slightly smaller than the size of the intact mRNA estimated by Northern blot (1800 bases). Our sequence data indicate differences with the previously published amino acid sequence involving 21% of the residues. They were entirely confirmed by the amino acid composition of the tryptic peptides derived from purified BPGM. The revised amino acid sequence of the human BPGM is presented.

Amino Acid Sequence↗
PubMed1986

Molecular cloning and sequencing of the human erythrocyte 2,3-bisphosphoglycerate mutase cDNA: revised amino acid sequence.

The human erythrocyte 2,3-bisphosphoglycerate mutase (BPGM) is a multifunctional enzyme which controls the metabolism of 2,3-diphosphoglycerate, the main allosteric effector of haemoglobin. Several cDNA banks were constructed from reticulocyte mRNA, either by conventional cloning methods in pBR322 and screening with specific mixed oligonucleotide probes, or in the expression vector lambda gt 11. The largest cDNA isolated contained 1673 bases [plus the poly(A) tail], which is slightly smaller than the size of the intact mRNA as estimated by Northern blot analysis (approximately 1800 bases). This cDNA encodes for a protein of 258 residues; the protein yielded 34 tryptic peptides which were subsequently isolated by h.p.l.c. Our nucleotide sequence data were entirely confirmed by the amino acid composition of these tryptic peptides and reveal several major differences from the published sequence; the revised amino acid sequence of human BPGM is presented. These findings represent the first step in the study of the expression and regulation of this enzyme as a specific marker of the erythroid cell line.

Amino Acid Sequence↗
PubMed1986

Cloning and sequencing of mRNAs coding for two adult alpha globin chains of the salamander Pleurodeles waltlii.

A cDNA library of erythrocyte mRNAs was established from immature red blood cells of the adult amphibian, Pleurodeles waltlii (urodele; salamander). The cDNA clones corresponding to the four adult globin chains were first identified and characterized by positive selection and the cDNAs derived from the two (major and minor) alpha-globin chains sequenced. The sequences presented contain both the complete 3'-noncoding region and the coding region of both chains, with the exception of the first nine codons of the minor alpha-chain, and a portion of the 5'-noncoding region of the major chain. The amino acid sequences of the encoded alpha-globin polypeptides have been deduced and compared with those of Xenopus laevis and of man. These comparative studies suggest that the alpha-globins of Pleurodeles waltlii and Xenopus laevis may have diverged from a common ancestral gene at the time when mammalian and amphibian lines diverged, and that they then evolved separately. Duplication of the alpha-gene, which is responsible for the polypeptide heterogeneity, appears to have occurred earlier in Pleurodeles waltlii than in Xenopus laevis.

Amino Acid Sequence↗
PubMed1977

Electrophoretic and kinetic studies of human erythrocytes deficient in pyrimidine 5'-nucleotidase.

A new case of a defect in red cell pyrimidine 5'-nucleotide (P5N) activity was found in a large family from Guadeloupe in the West Indies. The propositus presented a characteristic hemolytic anemia with red cell basophilic stippling, an increased GSH level, and a shift of the peak in absorbance of nucleotide. The enzyme activity from the deficient red cells differed from that of the normal. The P5N activity of the deficient red cells was about 14% that of normal. The electrophoretic pattern of P5N activity of the deficient red cells was distinct from that of the control in terms of its Km and of the effects of pH on its maximum activity and heat stability. The significance of such differences is discussed.

Anemia, Hemolytic, Congenital↗
PubMed1977

Electrophoretic characterization of pyrimidine 5'-nucleotidase of human erythrocytes and its distinction from acid phosphatase.

Electrophoresis of red cell pyrimidine 5'-nucleotidase was carried out on cellulose acetate strips. One major band of activity was found in preparations from human erythrocytes. This enzyme showed a specificity for the pyrimidine nucleotides UMP and CMP. No activity was detected with AMP. Pyrimidine 5'-nucleotidase activity could be separated from that of acid phosphatase with the use of alpha-glycerophosphate. This method may be useful in the study of pyrimidine 5'-nucleotidase deficiency in red cells.

Acid Phosphatase↗