In vivo synthesis and processing of cereal lectins.

The synthesis and processing of cereal lectins was followed in vivo. The initial translation products of lectin genes are higher molecular weight (28 K) precursors, which are post-translationally processed in a single step into authentic lectin polypeptides (23 K). The conversion of precursor into mature product is a rather slow process (the precursor has a half life of 36 min) and is apparently not a prerequisite for biological activity since the precursor exhibits sugar binding activity.

Lectin synthesis in developing and germinating wheat and rye embryos.

Wheat (Triticum aestivum L.) and rye (Secale cereale L.) lectins are specifically synthesized during seed formation.

In vitro synthesis of lectins in cell-free extracts from dry wheat and rye embryos.

Cell-free extracts from dry wheat (Triticum vulgare L.) and rye (Secale cereale L.) embryos do not synthesize their corresponding lectins when incubated under conditions optimalized for translation of either exogenous or endogenous mRNA.

Isolation and partial characterization of a lectin from a false brome grass (Brachypodium sylvaticum).

A lectin has been isolated from embryos of a false brome grass species (Brachypodium sylvaticum) by affinity chromatography on immobilized N-acetylglucosamine. It is a dimeric protein of two identical subunits of mol.wt.

Subunit exchange between lectins from different cereal species.

Lectins from Triticum monococcum, Secale cereale (rye), and Hordeum vulgare (barley) can exchange their subunits in vitro and thereby form (intergeneric) heteromeric lectins. An analysis of the isolectin pattern of a Triticale variety revealed that intergeneric heterodimers of wheat and rye lectin subunits are normal constituents of the embryo cells. It appears, therefore, that these different cereal lectins are structurally so closely related that their subunits can not distinguish between identical and nonidentical partners when they associate into dimers.

A genetic basis for the origin of six different isolectins in hexaploid wheat.

Wheat (Triticum aestivum) germ agglutinin represents a complex mixture of multiple isolectin forms. Upon ion exchange chromatography at pH 3.8, three isolectins can be separated, each of which is composed of two identical subunits.

Isolation and partial characterization of wheat-germ-agglutinin-like lectins from rye (Secale cereale) and barley (Hordeum vulgare) embryos.

Lectins have been isolated from embryos of Secale cereale (rye) and Hordeum vulgare (barley) by affinity chromatography on immobilized N-acetylglucosamine. Both lectins are dimeric proteins of two identical subunits of mol.wt.

Efficient translation of long-lived messengers in extracts from dry pea primary axes : Evidence for the presence of lectin mRNA.

Extracts prepared from dry pea (Pisum sativum, L; cv oberon) primary axes translate efficiently their endogenous messengers in an in vitro protein synthesizing system. The native long-lived messengers are biologically fully active and direct the synthesis of a whole range of polypeptides with MW ranging up to 130,000. About 0.

Preparation and Characterization of a Highly Active Cell-free Protein-synthesizing System from Dry Pea Primary Axes.

A highly active and reliable cell-free protein-synthesizing system from dry pea primary axes has been developed. The system has been optimized with respect to both overall activity and translational fidelity. Under optimal conditions, the system incorporates nearly 1,000 picomoles leucine per 50 microliters incubation mixture.

Characterization of a maturation-specific mRNA in dry mung bean embryonic axes.

The poly(A)-rich RNA from dry mung bean (Vigna radiata [L.] Wilczek) embryonic axes has been isolated and translated in a wheat embryo cell-free system, and the products were analyzed on sodium dodecyl sulfate-polyacrylamide gels. The fluorographyic patterns showed a heavy band at approximately MW 12,000.

Botanical aspects of cell-free protein synthesizing systems from cereal embryos.

Some botanical aspects of cell-free protein synthesizing systems from cereal embryos have been investigated. The composition of the starting material determines both the stability and translation fidelity of the cell-free extracts. The active components of the extracts originate exclusively from the primary axes.

Cell-free translation of exogenous mRNA in extracts from dry pea primary axes.

Extracts from the primary axes of dry pea (Pisum sativum L.) seeds are able to perform an initiation-dependent translation of exogenous mRNA. SDS polyacrylamide gel electrophoresis of the products synthesized under direction of alfalfa mosaic virus RNA (AMV-RNA) and tobacco mosaic virus RNA (TMV-RNA) shows that the fidelity of translation in this pea system is at least as high as in a wheat embryo cell-free protein synthesizing system.

Preformed and newly synthesized messenger RNA in germinating wheat embryos.

In 6 h germinated wheat (Triticum aestivum L. cv. Cama) embryos, more than half of the messenger RNAs are actively involved in translation.

Some aspects of the synthesis of long-lived messenger ribonucleoproteins in developing rye embryos.

Untranslated messenger ribonucleoproteins (mRNPs informosomes) are present in developing rye (Secale cereale, L. cv. Celestijner) embryos throughout the last 5 weeks of seed formation.

Sedimentation properties of preformed messenger particles in dry rye embryo extracts.

Two classes of messenger containing particles can be distinguished in cell-free extracts from dry rye (Secale cereale, L.; var. Celestijner) embryos.