Mitogenic properties of pokeweed lectin-D isoforms on human peripheral blood lymphocytes: non-mitogen PL-D1 and mitogen PL-D2.

We investigated native structures and mitogenic properties of pokeweed lectin-D isoforms (PL-D1 and -D2) on human peripheral blood lymphocytes along with other isolectins (PL-A to -C). Both native PL-D isoforms appeared to behave as monomers. PL-D2 proliferated the lymphocytes like PL-C, whereas PL-D1 had no mitogenicity.

Structures of two lectins from the roots of pokeweed (Phytolacca americana).

Pokeweed lectin (PL), a lectin specific for N-acetylglucosamine-containing saccharides, stimulates peripheral lymphocytes to undergo mitosis by binding to their cell surfaces. Four types of lectins have been isolated from the roots of pokeweed (Phytolacca americana) and shown to contain homologous domains but to have different molecular sizes and biological properties. PL-D, the smallest lectin in the group, has two isolectins, PL-D1 and PL-D2.

Molecular cloning, functional expression, and mutagenesis of cDNA encoding class I chitinase from rye (Secale cereale) seeds.

A cDNA encoding rye seed chitinase-a (RSC-a) was cloned by rapid amplification of cDNA ends and PCR procedures. It consists of 1,191 nucleotides and encodes an open reading frame of 321 amino acid residues. Recombinant RSC-a (rRSC-a) was produced in the oxidative cytoplasm of Escherichia coli Origami(DE3) in a soluble form by inducing bacteria at a low temperature (20 degrees C).

Similarity between protein-protein and protein-carbohydrate interactions, revealed by two crystal structures of lectins from the roots of pokeweed.

The roots of pokeweed (Phytolacca americana) are known to contain the lectins designated PL-A, PL-B, PL-C, PL-D1, and PL-D2. Of these lectins, the crystal structures of two PLs, the ligand-free PL-C and the complex of PL-D2 with tri-N-acetylchitotriose, have been determined at 1.8A resolution.

Crystallization and preliminary X-ray analysis of lectin C from the roots of pokeweed (Phytolacca americana).

Lectin C from the roots of pokeweed (Phytolacca americana) (PL-C; 13 747 Da, 126 amino-acid residues), which consists of three chitin-binding domains, was initially crystallized in two crystal forms. One form, obtained in the presence of 30%(w/v) PEG 4000, belongs to the tetragonal system. The other, obtained in the presence of 2.

Mutational analysis of amino acid residues involved in catalytic activity of a family 18 chitinase from tulip bulbs.

We expressed chitinase-1 (TBC-1) from tulip bulbs (Tulipa bakeri) in E. coli cells and used site-directed mutagenesis to identify amino acid residues essential for catalytic activity. Mutations at Glu-125 and Trp-251 completely abolished enzyme activity, and activity decreased with mutations at Asp-123 and Trp-172 when glycolchitin was the substrate.

Antifungal activity of rye (Secale cereale) seed chitinases: the different binding manner of class I and class II chitinases to the fungal cell walls.

The antifungal activities of rye seed chitinase-a (RSC-a, class I) and -c (RSC-c, class II) were studied in detail using two different bioassays with Trichoderma sp. as well as binding and degradation experiments with the cell walls prepared from its mycelia. RSC-a inhibited more strongly the re-extension of the hyphae, containing mainly mature cells, than RSC-c did.

Molecular cloning, functional expression, and mutagenesis of cDNA encoding rye (Secale cereale) seed chitinase-c.

We cloned a complete cDNA encoding rye seed chitinase-c, designated RSC-c, by rapid amplification of cDNA end and PCR procedures. The cDNA of RSC-c consists of 1,018 nucleotides and includes an open reading frame encoding a polypeptide of 266 amino acid residues. A recombinant RSC-c was produced by expression in Escherichia coli Origami(DE3) and purified.