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C Lazure

Publications and source records attributed to C Lazure.

At least 109 records · Page 6Linked to original sources
PubMed1987

Amino acid sequence of rabbit kidney neutral endopeptidase 24.11 (enkephalinase) deduced from a complementary DNA.

Neutral endopeptidase (EC 3.4.24.11) is a major constituent of kidney brush border membranes. It is also present in the brain where it has been shown to be involved in the inactivation of opioid peptides, methionine- and leucine-enkephalins. For this reason this enzyme is often called 'enkephalinase'. In order to characterize the primary structure of the enzyme, oligonucleotide probes were designed from partial amino acid sequences and used to isolate clones from kidney cDNA libraries. Sequencing of the cDNA inserts revealed the complete primary structure of the enzyme. Neutral endopeptidase consists of 750 amino acids. It contains a short N-terminal cytoplasmic domain (27 amino acids), a single membrane-spanning segment (23 amino acids) and an extracellular domain that comprises most of the protein mass. The comparison of the primary structure of neutral endopeptidase with that of thermolysin, a bacterial Zn-metallopeptidase, indicates that most of the amino acid residues involved in Zn coordination and catalytic activity in thermolysin are found within highly honmologous sequences in neutral endopeptidase.

Amino Acid Sequence↗
PubMed1987

The major 40-kDa glycoprotein in human prostatic fluid is identical to Zn-alpha 2-glycoprotein.

A major 40-KDA protein secreted by human prostate was isolated from whole seminal plasma by sequential column chromatography on DEAE-Sepharose CL-6B, concanavalin A(Con A)-Sepharose, and Sephadex G-100. Although the purified preparation still contained minor contaminants, its amino acid composition was found to be identical to the one of a glycoprotein isolated previously from seminal plasma by Lin et al (1983). Antibodies against this protein were produced in rabbits and their use in immunoblotting experiments revealed the presence of the antigen in several tissues including the prostate, the liver, the heart, the kidney, the epididymis, and the testis. A radioimmunoassay confirmed these results and showed that blood serum concentrations of this protein were relatively high in men (81 +/- 3 micrograms/ml), women (68 +/- 3 micrograms/ml), and cord blood of newborns (32 +/- 1 micrograms/ml). The serum concentrations of this protein along with its physicochemical characteristics suggested that it could be identical to Zn-alpha 2-glycoprotein, a human serum protein previously isolated by Burgi and Schmid (1961). This hypothesis was confirmed by a double immunodiffusion analysis using a commercial anti-Zn-alpha 2-glycoprotein antiserum. Finally, in vitro translation of prostatic poly(A) + RNA in rabbit reticulocyte lysate in the presence of canine pancreatic microsomal membranes resulted in the formation of an immunoprecipitable 42-kDa band. These results show that Zn-alpha 2-glycoprotein can be synthesized in the prostate itself. The demonstration of high concentrations of this protein in prostatic tissue and prostatic secretion should facilitate the elucidation of its role in the prostate and in other tissues.

Amino Acids↗
PubMed1987

Molecular cloning and sequence of the cDNA for a 94-amino-acid seminal plasma protein secreted by the human prostate.

The precursor to a seminal plasma protein reported to have inhibin-like activity was characterized through cDNA cloning and sequencing. It is a 114-amino-acid polypeptide which differs from its seminal plasma derivative mainly by the presence of a 20-residue amino-terminal extension, a putative signal sequence, carrying a possible N-glycosylation site. The protein is specified by a single gene per haploid genome. Its mRNA is detectable in the prostate but not in the testis, which suggests that it is primarily a prostatic secretory protein.

Amino Acid Sequence↗
PubMed1987

Complete amino acid sequence of a VLDV-type neurophysin from ostrich differs markedly from known mammalian neurophysins.

The neurohypophyseal hormones vasopressin and oxytocin are known to be synthesized in eutherian mammals as part of larger precursors containing either MSEL- or VLDV-neurophysins. A neurophysin has been isolated from ostrich neurohypophyses and shown by partial amino acid sequence determination to be related to mammalian VLDV-neurophysin. The present report describes the complete amino acid sequence of this ostrich neurophysin containing 93 residues. This amino acid sequence, the first reported in birds, differs in a remarkable manner from its mammalian homolog. Indeed, it contains a large number of substitutions, including one insertion, distributed throughout the polypeptide chain when compared to known VLDV-neurophysins. Whereas many of these substitutions are localized inside the so-called constant region of the neurophysin, the highest variation can be found in the COOH-terminal region.

Amino Acid Sequence↗
PubMed1987

The complete amino acid sequence of rat submaxillary gland tonin does contain the aspartic acid at the active site: confirmation by protein sequence analysis.

The revised amino acid sequence of rat submaxillary gland tonin, a serine protease, does contain the active site Asp residue. The active site of this kallikrein-related enzyme is thus made up of the same catalytic triad (Asp, Ser, and His) found in all known serine proteases. The important Asp residue has now been localized in a 16 amino acid peptide previously reported as missing in the tonin sequence. The complete amino acid sequence thus contains 235 residues corresponding to a molecular weight of 25,658, more in agreement with previously reported molecular weights. Moreover, the revised structure led (a) to the assignment of Arg, Asn, and Val residues instead of His, Asp, and Gly at positions 63, 165, and 169, respectively; (b) to the assignment of residues occupying an overlapping sequence at positions 165-171, and finally (c) to the localization of two N-glycosylation sites at positions 82 and 165. These results further document the close relationship of tonin to the ever expanding kallikrein family.

Amino Acid Sequence↗
PubMed1987

Regulation of carbonic anhydrase III by thyroid hormone: opposite modulation in slow- and fast-twitch skeletal muscle.

This laboratory previously reported that a major 30 kilodalton (kDa) protein of the soluble cytoplasmic fraction of the rat slow-twitch soleus muscle is modulated by thyroid hormone. This protein has been purified and a portion of the primary structure has been determined. The sequence analysis suggested that the 30-kDa protein is carbonic anhydrase III (CA III; EC 4.2.1.1). The reaction of the protein with a CA III specific antibody and the similar modulation of CA III by thyroid hormone also support this conclusion. Immunochemical quantification of CA III and measurement of CA activity were performed in skeletal muscles of defined fiber-type composition from rats that were rendered hyperthyroid by treatment with 3,3',5-triiodo-L-thyronine. These experiments revealed that CA activity and CA III content are deinduced in the soleus muscle (primarily type I fibers) and induced in the superficial vastus lateralis muscle (primarily type IIb), whereas no changes were detected in the tibialis anterior muscle (primary type IIa). These results show that the modulation of CA III by thyroid hormone in rat skeletal muscle is not limited to the slow-twitch soleus muscle and that the amplitude and direction of this modulation are directly related to the initial fiber-type composition of the skeletal muscle.

Amino Acid Sequence↗
PubMed1986

Complete amino acid sequence of Shigella toxin B-chain. A novel polypeptide containing 69 amino acids and one disulfide bridge.

The complete amino acid sequence of the B-chain of Shigella toxin has been determined using both liquid- and gas-phase sequenators. It reveals a 69-amino acid peptide with a single disulfide bridge, predicting a subunit molecular weight of 7691. No Asn-X-Ser(Thr) sequence was found, confirming the absence of potential N-glycosylation sites. A computer data bank search using a mutation data matrix did not detect any similarity greater than 30% with known sequences to date, indicating a novel primary structure. However, some distant homology with the 103-residue B-chain of cholera and Escherichia coli enterotoxins was revealed. Hydropathy, fractional exposure, and Chou and Fasman calculations all point to an ordered structure with a hydrophobic core spanning residues 36-52 and a hydrophilic domain between residues 10 and 20, the latter probably representing the most antigenic domain.

Amino Acid Sequence↗
PubMed1986

Purification and sequence determination of bovine atrial natriuretic factor.

We report the purification and the sequence determination of bovine atrial natriuretic factor (ANF) in acid extracts of bovine atrial appendages. The monitoring of the activity along the purification steps was performed with a radio-receptor assay using bovine adrenal cortex membranes sites and 125I ANF. Bovine ANF was separated by carboxymethyl agarose gel chromatography from catecholamines and major protein contaminants. It behaved as a 3 K dalton peptide on Sephadex G-50. The active fractions were then subjected to high performance liquid chromatography (HPLC) using a sulfopropyl cation exchange column. Subsequent purification steps by reverse phase mode on Ultrapore RPSC, Vydac TP 218 and uBondapak using acetonitrile gradients led to the obtention of a pure fraction which amino acid sequence was identical to that for human ANF. This confirms the high degree of homology of ANF structure among mammalian species and advocates the use of the radio-receptor assay based on bovine adrenal receptor for measuring human ANF.

Adrenal Glands↗
PubMed1986

Identification of the released form of atrial natriuretic factor by the perfused rat heart.

Atrial natriuretic factor (ANF), released by the isolated perfused rat heart, was extracted from the perfusates by C18 Sep-Pak cartridges and then isolated by immunoaffinity chromatography and by reverse phase HPLC. About 500 ng of immunoreactive material were so obtained and submitted to amino acid sequencing. The C-terminal Tyr was detected by radiolabelling. Identification of these residues indicated that the primary structure corresponds to ANF (Ser 99-Tyr 126) which is identical to the circulating form in the rat. These results indicate that the ANF released by the atria corresponds to a short peptide. Therefore, its maturation process may therefore take place either intracellularly or during secretion and implicates a tryptic-like cleavage after a single Arg residue in position 98.

Amino Acid Sequence↗
PubMed1986

[The Alpabem, an association of parents of young adults with symptoms of chronic mental illness.].

This article describes the stages encountered in the creation of an association for the parents of young adults with schizophrenia related symptoms. The association's mode of operation is also studied. The association's impact on the families'reactions to the illness is observed as well as the evolution of the psychiatric workers in charge of the beneficiaries. This article also deals with the social influence of such an organization.

English Abstract↗
PubMed1986

Dog prostate arginine esterase is related to human prostate specific antigen.

We have analyzed prostatic proteins of canine and human seminal plasma. We have compared in particular the physicochemical characteristics of arginine esterase from dog to those of the prostatic specific antigen from man. Both are major secretory proteins in each species. Arginine esterase and prostate specific antigen are related enzymes belonging to the serine-protease class. Their enzymatic activity towards protein substrates appears similar. However their activity towards synthetic substrates indicate that arginine esterase is a trypsin-like enzyme whereas prostate specific antigen has some chymotrypsin-like activity. The canine enzyme is inhibited by phenylmethylsulfonyl fluoride while the human one is not. The amino acid sequence of a portion of the NH2-terminal of the 2 proteins share 58% homology. Their molecular weights are similar: 29 KDa for arginine esterase and 34 KDa for prostate specific antigen. These results show that arginine esterase and prostate specific antigen are distinct but closely related proteins. These results strongly suggest that the dog could be an excellent model for the elucidation of the presently unknown role of this class of abundant enzymes of prostatic origin.

Amino Acid Sequence↗
PubMed1985

Structure-activity relationships of atrial natriuretic factor (ANF). III. Correlation of receptor affinity with relative potency on aldosterone production in zona glomerulosa cells.

The activity of various fragments of ANF as inhibitors of aldosterone secretion and as competitors of [125I] ANF (Arg101-Tyr126) binding to specific receptors was studied in bovine zona glomerulosa. Shortening or lengthening the N-terminal segment of ANF does not alter its biological activity while minimally altering affinity for its receptor. Removal of the C-terminal to Cys121 or expansion up to Arg128 leads to 1000-fold decrease in receptor affinity and activity. The results indicate the importance of the C-terminal segment of ANF in determining its active conformation.

Adrenal Cortex↗
PubMed1985

Identification of a biologically active circulating form of rat atrial natriuretic factor.

An atrial natriuretic peptide has been isolated from plasma of morphine treated rats by means of glass beads extraction, immunoaffinity chromatography, and reverse phase HPLC. 1.3 micrograms of immunoreactive material was obtained. The biological activity of this material was found comparable to that of ANF (Arg 101 - Tyr 126) on the inhibition of basal aldosterone secretion by rat adrenal zona glomerulosa cells and the displacement curve of iodinated ANF from ANF receptors in a mesenteric artery preparation. Gas phase amino acid sequencing indicated that it is related to ANF (Ser 99 - Tyr 126). These results suggest that the maturation of ANF may require a tryptic-like cleavage after a single Arg residue.

Adrenal Cortex↗
PubMed1985

ANF (Arg 101--Tyr 126) is the peptide secreted by rat atrial cardiocytes in culture.

The atrial natriuretic factor (ANF) secreted from rat cardiocytes in culture was purified and characterized. The purification procedure involves extraction of ANF by activated Vycor glass, followed by HPLC on C18 mu Bondapak and Vydac columns. The detection of ANF in column eluates was performed by a simple and sensitive radioimmunoassay. The amino acid composition and N-terminal amino acid sequencing appeared to be identical to the Arg 101 - Tyr 126 peptide. The isolated ANF showed biological activity, inhibiting basal and ACTH-stimulating aldosterone secretion from rat zona glomerulosa cells with the same potency as the synthetic peptide.

Adrenal Glands↗
PubMed1985

Structure-activity relationships of atrial natriuretic factor (ANF). II. Effect of chain-length modifications on vascular reactivity.

The effect of the length of ANF peptides on the inhibition of the norepinephrine-induced contraction was studied. Starting from the 26 residues ANF (Arg101-Tyr126), shorter N- and/or C-terminal fragments were produced, either by N-terminal chemical cleavage or C-terminal enzymatic digestion of ANF or both respectively. The N-terminal removal of Arg101 did not modify the inhibitory response. Further N-terminal truncation up to des-Arg101-Arg102-Ser103-Ser104 ANF still produced a marked inhibitory effect on norepinephrine. In contrast C-terminal cleavage had a much more pronounced effect. Since des-Tyr126 ANF, des-Arg125-Tyr126 ANF and des-Phe124-Arg125-Tyr126 ANF exhibit much lower activities than the parent ANF. Finally, when the 5 residues C-terminal to Cys121 are removed, the resulting molecule is almost inactive. These data indicate that the C-terminal segment of ANF may modulate the binding of ANF to its receptor(s). Relatively, the N-terminal region seems to be much less important.

Animals↗
PubMed1985

GAWK, a novel human pituitary polypeptide: isolation, immunocytochemical localization and complete amino acid sequence.

During the course of reverse-phase high pressure liquid chromatography (RP-HPLC) purification of a postulated big ACTH (1) from human pituitary gland extracts, a highly purified peptide bearing no resemblance to any known polypeptide was isolated. The complete sequence of this 74 amino acid polypeptide, called GAWK, has been determined. Search on a computer data bank on the possible homology to any known protein or fragment, using a mutation data matrix, failed to reveal any homology greater than 30%. An antibody produced against a synthetic fragment allowed us to detect several immunoreactive forms. The antisera also enabled us to localize the polypeptide, by immunocytochemistry, in the anterior lobe of the pituitary gland.

Amino Acid Sequence↗
PubMed1985

Metabolism of radioiodinated carboxy-terminal fragments of bovine parathyroid hormone in normal and anephric rats.

[125I]Carboxy-terminal fragments were produced by incubating [125I]bovine PTH(1-84) with plasma membranes from the rat renal cortex. After purification by gel chromatography and characterization by sequence analysis, these fragments, mainly [125I]bovine PTH(41-84), were injected into normal and acutely nephrectomized rats during two different experiments. In each case, blood was obtained from five rats at various time points (2, 4, 6, 8, 12, 24, 48, and 96 min); tissue was taken after they had been killed (4, 8, 24, and 96 min). Plasma and weighted aliquots of tissues were counted. Plasma at each time point and the extract of various tissues at the 8-min mark were further analyzed by gel chromatography. Each radioactivity peak on each profile was identified and quantitated planimetrically. [125I]Carboxy-terminal fragments were extracted from serum biexponentially: the first exponential had a half-life of 2.3 min and the second 27.2 min in normal rats. These values increased to 3.2 min (X 1.4) and 74.0 min (X 2.7) in nephrectomized rats. In normal rats, 125I-extraction was 33.4% (kidney), 15.9% (muscle), 6.9% (bone), less than 2.7% (liver), and under 1% in other tissues. In nephrectomized rats, these values were significantly (P less than 0.005) increased to 24.6% (muscle), 10% (bone), and 6.8% (liver) with less than 1% in other tissues. Most of the 125I-radioactivity present in these tissues at the 8-min time point migrated in the same manner as injected fragments or smaller degradation products generated in situ. Tissues which play a secondary role in circulating carboxy-terminal fragment extraction in normal rats can therefore increase this activity in anephric animals. Extraction overall remains less efficient, as demonstrated by the longer half-life of fragments in nephrectomized rats.

Animals↗