Site-directed mutagenesis and expression in Escherichia coli of WMAI-1, a wheat monomeric inhibitor of insect α-amylase

The wheat monomeric inhibitor WMAI-1 (syn. 0.28) produced inEscherichia coli using the pT7-7 expression ventor has the correct N-terminal sequence and the same electrophoretic mobility and specific activity towards the -amylase from the insectTenebrio molitor as the native WMAI-1 isolated from wheat. This confirms that the native inhibitor is not glycosylated and contradicts claims that a putative glycosyl moiety was essential for inhibition. Thirteen mutants have been obtained at six different sites. Substitution of the highly conserved N-terminal S by the sequence ARIRAR increased the pre-incubation time required for maximum activity. A similar result was obtained by insertion of GPRLPW after position 4, while insertion of EPRAPW at the same position rendered the inhibitor inactive. The substitution D/EGPRL and insertions DGP or D, at position 58, produced complete inactivation. All other mutations had only minor effects on activity

Nigrosine staining of wheat endosperm proteolipid patterns on starch gels

We have previously characterized a group of proteolipids from wheat endosperm, designated CM proteins, which are soluble in chloroformmethanol (2:1, v/v) and have a molecular weight lower than 25,000 daltons (1-3). These have been also studied by Redman and Ewart (4). The CM proteins are suitably fractionated into several components by starch gel electrophoresis at pH 3.2 (1). A sensitive staining procedure was required in connection with genetic studies of these proteins because phenotypes had to be ascertained in small endosperm fractions dissected without impairing normal germination and plant development. We report here on Nigrosine staining conditions for CM proteins under which high sensitivity and selectivity are achieve

Nucleotide sequence of a cDNA encoding an α/β-type gliadin from hexaploid wheat (Triticum aestivum).

A cDNA clone was isolated from a library obtained from developing endosperm of cv. Chinese Spring which encoded an α/β-type gliadin that differs from previously described ones. The nucleotide sequence and deduced amino acid sequence of the new clone, designated MM1, are presented

cDNAs of a wheat tetrameric inhibitor of a-amylases

In the laboratory of M. Metzlaff, genome specific DNA probes from Hordeum vulgare were cloned and characterized by H. Junghans. Regarding repeated DNA sequences our further investigations will concéntrate on the proofof alien chromatin in the wheat -Ae. markgrafii crossing material and on the enlargement of the investigation to their distribution in Poaceae species

Effects of n-butanol and filipin on membrane permeability of developing wheat endosperm with different sterol phenotypes.

Sterols are considered structural components of higher plant membranes on the basis of their presence in membrane-containing subcellular fractions [1—3], their effect on plant membrane permeability when added exogenously [4,5] and the sensitivity of plant cells to the polyene antibiotic filipin [6—8], which action is known to depend on the presence of sterols in the membrane (see [8]). Our recent finding of a gene that controls the free sterol level of developing wheat endosperm [9—11 ] allows to investígate whether endogenous sterol modifies membrane permeability in the same way as that added externally. We report here on the effect of «-butanol and filipin on the leakage properties of developing wheat endosperms with different genetically determined free sterol levéis

Heterogeneity of wheat endosperm proteolipids (CM proteins)

Proteins extracted with CHCl3-MeOH from wheat endosperm have been fractionated by Sephadex G-100 and the 15 000–20 000 MW range fraction, designated CM protein, has been examined by combined electrofocusing (pH range 5–8) and electrophoresis (pH 3.2) and the heterogeneity of the electrophoretic components has been ascertained. It has been shown by joint mapping and by sequential extraction that CM proteins are extracted by 70% EtOH but not by H2O, although they can be made water-soluble after dialysis against an acid buffer, pH 3.2, 3 M urea, without losing their solubility in CHCl3-MeOH mixtures. It is concluded that CM proteins fit the definition of a Folch—Lees proteolipid. The Triticum aestivum (genomes ABD) map can be reconstructed by mixing T. durum (AB) and Aegilops squarrosa (D). The low intragenomic variability of CM protein is confirmed

Chromosomal location of a gene that controls sterol esterification in Triticum aestivum L.

A previously described D genome locus (Pln) that controls sterol esterification in the wheat kernel has been assigned to the short arm of chromosome 7 D by comparison of the steryl ester phenotype of euploid kernels of Triticum aestivum variety Chinese Spring with those of the compensated nulli-tetrasomic lines and the 7 D S ditelosomic. Palmitate is the predominant ester in all but the 7 D nullisomic combinations, which have linoleate as the main ester. These lines also show a marked decrease in sterol esterification and a two-fold increase in free sterol, indicating that chromosomes 7 A and 7 B do not compensate for the loss of esterification capacity associated with 7 D

Translation and interpreting : Bridges across languages and cultures

This chapter looks at how translation and interpreting make communication across languages and cultures possible. After completing the chapter's activities, students will be able to: · Explain the complexity of communication across languages · Describe the value of translation and interpreting as a form of communication across languages · Distinguish between an interpreter and a translator · Give examples of misunderstandings inherent to communication, even in the absence of language barriers · Describe some of the difficulties translators and interpreters face and must overcom