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L Charbonnier

Publications and source records attributed to L Charbonnier.

10 recordsLinked to original sources
PubMed1982

The toxic fraction of gliadin digests in coeliac disease. Isolation by chromatography on Biogel P-10.

Improvement in the fractionation of gliadin digests and in the isolation of toxic fractions was achieved using chromatography on Biogel P-10. Fraction V, one of the 11 fractions eluted from a peptic-tryptic digest of crude gliadin extracted from Cappelle wheat, significantly affected coeliac jejunal mucosa in organ culture. BV, gamma V, omega V, the corresponding fractions V from beta-, gamma- and omega-gliadins, displayed similar toxic effects. Fraction VI containing peptides with a lower molecular mass did not show any significant cytotoxic activity and, moreover, inhibited the toxicity of fraction V. Analysis of the toxic fractions V showed that they contained peptides of 7-8,000 molecular mass, rich in proline and glutamine and poor in aromatic amino acids and carbohydrates. Among the various fractions, V, beta V from beta-gliadin appeared the less heterogeneous.

Amino Acids↗
PubMed1980

Isolation and characterization of beta-gliadin fractions.

beta-Gliadins of Cappelle wheat are distributed in three subsets in starch gel electrophoresis at pH 3.2, Six of these beta components have been isolated by sulfopropyl-Sephadex C-50 chromatography, gel filtration on Sephadex G-100 and sulfoethyl-cellulose chromatography. Apparent molecular weights determined by gel filtration and SDS-polyacrylamide gradient gel electrophoresis are between 29 000 and 35 000. Valine is the N-terminal amino acid of all beta-gliadins with the exception of the slowest component in electrophoresis at pH 3.2 the N-terminal amino acid of which is asparagine. The main difference between the amino acid compositions is the lack of tryptophan in the fastest of the three component subsets visible in electrophoresis at pH 3.2.

Amino Acids↗
PubMed1980

[Comparative toxicity of different cereals for subjects intolerant of gluten].

Coeliac disease is caused by prolamines, the storage proteins of some cereals, located in the endosperm. Cereals do not all have the same toxicity. The four wheat prolamine groups (alpha, beta, gamma and omega gliadins), visible in electrophoresis at acid pH, have been isolated and their toxicities compared by observing the morphological changes in intestinal biopsies cultured in vitro when peptic-tryptic digests of the studied proteins were added to the culture medium. The toxicity was found to be mainly located in the alpha and beta-gliadins and in peptides of 5 to 10 000 molecular weight. Peptides, resulting from peptic-tryptic hydrolysis, varied in length as a direct function of their proline content. In fact, peptide bond splitting by pepsin and trypsin is known to be blocked by proline. Thus, proline content determines peptide length and toxicity. Wheat, rye and barley toxicities were compared on the basis of a correlation between toxicity and the alpha- and beta-gliadin-like prolamine contents of these cereals. Electrophoretic estimation of alpha- and beta-gliadin-like prolamine content gave the following prediction of relative toxicity (in decreasing order): wheat, triticale, rye, barley and oats.

Amino Acids↗
PubMed1978

Heterogeneity of avenin, the oat prolamin. Fractionation, molecular weight and amino acid composition.

The prolamin, avenin, was extracted from oat seeds and shown to be maximally extractable in 45% (w/w) ethanol. A purification procedure is described and some properties of avenin are examined. As with wheat and barley prolamins, salt soluble and glutelin fractions were simultaneously extracted. Starch gel electrophoresis revealed two novel fractions, which were isolated by ion-exchange chromatography. These fractions have similar amino acid composition, threonine as the N-terminal amino acid and both have a 22 500 molecular weight. It is suggested that the avenin constituents have a common ancestral gene.

Amino Acids↗
PubMed1976

[Nature and fractionation of barley proteins extracted by ethanol, isopropanol and n-propanol in different proportions].

Barley alcoholsoluble protein extractabilities by aqueous ethanol, isopropanol and n-propanol were measured at room temperature. The quantities extracted by each alsohol strongly depend on the concentration of the alcohol. The most efficient concentration for the three alcohols were by increasing order: 45 per cent ethanol, 40 per cent isopropanol, 35 per cent (w/w) n-propanol. Hrodein preparations extracted by these three alcoholic solutions and by 75 per cent (w/w) ethanol were compared by means of the flour nitrogen percentage they contain and by electrophoresis, amino-acid analysis and Sephadex G 100 gel filtration. The preparations studied do not differ markedly in their amino-acid composition or electrophoretic pattern which shows at least 17 different bands. On the other hand, Sephadex G 100 gel filtration separates two main groups of proteins, The first one is present at the same level in all preparations studied and consists of electrophoretically typical hordeins (already described hordeins). The other group represents a fraction of the preparation, the more abundant as the solvent is more effective. This second group is excluded on Sephadex G 100 chromatography and does not give well defined bands by starch gel electrophoresis. Consequently it is related to some glutelins. Nevertheless its amino-acid composition is very close to the mean hordein composition. Electrophoretic comparison with glutelins extracted by acetic acid and with hordeins, all reduced and alkylated, discloses a great similitude between this fraction, the glutelins and some hordein fast components alpha, beta and gamma.

1-Propanol↗
PubMedDate not supplied

The cytoplasmic male-sterility (CMS) determinant of common bean is widespread in Phaseolus coccineus L. and Phaseolus vulgaris L.

To identify regions of the mitochondrial genome that potentially could specify cytoplasmic male sterility (CMS) in Phaseolus coccineus (including P. polyanthus), and to define differences amongst P. coccineus lines, mitochondrial (mt)DNA restriction patterns and Southern blots of total DNA from sterile and fertile lines were analysed. By restriction endonuclease mapping we isolated a region which was specific to CMS lines flanking an F1-ATPase alpha-subunit (atpA) gene. DNA sequence analysis of this region showed 99.9% homology to the region previously isolated from P. vulgaris CMS Sprite. A high frequency of plants carrying the CMS-fragment was observed in a wild Phaseolus population, perhaps explaining the occurrence of inter- and intra-specific gene flow observed in the autogamous species P. vulgaris.

Blotting, Southern↗