Characterization of highly toxic type 2 ribosome-inactivating proteins from Adenia lanceolata and Adenia stenodactyla (Passifloraceae).

From the caudices of the Passifloraceae Adenia lanceolata and A. stenodactyla, two lectins called lanceolin and stenodactylin, respectively, were purified by affinity chromatography on CL Sepharose 6B. The lectins are glycoproteins with M(r) 61,243 (lanceolin) and 63,131 (stenodactylin), consisting of an enzymatic A chain linked to a larger B chain with lectin properties, with N-terminal amino acid sequences similar to that of volkensin, the toxic lectin from A.

Detection of ricin and other ribosome-inactivating proteins by an immuno-polymerase chain reaction assay.

Ribosome-inactivating proteins (RIPs) are plant proteins with enzymatic activity, classified as type 1 (single chain) or type 2 (two chains). They are identified as rRNA N-glycosidases (EC 3.2.

Ribosome-inactivating proteins and other lectins from Adenia (Passifloraceae).

The caudices of 10 Adenia species contain galactose-binding lectins that were purified by affinity chromatography. All lectins but three agglutinate human erythrocytes. Six lectins consist of two unequal chains, which can be separated by reduction, and inhibit protein synthesis both by a rabbit reticulocyte lysate and by HeLa and Raji cells.

Selective lesions of rabbit extraocular muscles injected with the anti-AChR immunotoxin saporin-mAb 73.

Purpose: To evaluate the effects on extraocular muscles of a skeletal muscle-specific immunotoxin, saporin-mAb 73, as an alternative to botulinum toxin to induce a permanent correction of oculo-facial dystonias or some forms of ocular motility disorders.

Methods: An immunotoxin was prepared with a monoclonal antibody (mAb 73) against acetylcholine receptors of skeletal muscle, linked to saporin, a type 1 ribosome-inactivating protein (RIP) from Saponaria officinalis. Sixteen New Zealand white rabbits were treated with a single injection of immunotoxin directly into the medial rectus muscle of one eye.

Novel poly(ethylene glycol) derivatives for preparation of ribosome-inactivating protein conjugates.

This study describes the synthesis, characterization, and reactivity of new methoxypoly(ethylene glycol) (mPEG) derivatives containing a thioimidoester reactive group. These activated polymers are able to react with the lysyl epsilon-amino groups of suitable proteins, generating an amidinated linkage and thereby preserving the protein's positive charge. mPEG derivatives of molecular weight 2000 and 5000 Da were used, and two spacer arms were prepared, introducing chains of different lengths between the hydroxyl group of the polymer and the thioimidate group.

Cloning and expression of cDNA coding for bouganin.

Bouganin is a ribosome-inactivating protein that recently was isolated from Bougainvillea spectabilis Willd. In this work, the cloning and expression of the cDNA encoding for bouganin is described. From the cDNA, the amino-acid sequence was deduced, which correlated with the primary sequence data obtained by amino-acid sequencing on the native protein.

Ribosome-inactivating and adenine polynucleotide glycosylase activities in Mirabilis jalapa L. tissues.

Several tissues of Mirabilis jalapa L. (Nyctaginaceae) were assayed for inhibition of translation by a rabbit reticulocyte lysate (as a signal of ribosome-inactivating activity) and for adenine DNA glycosylase activity, activities that are both due to the presence of a class of enzymes called ribosome-inactivating proteins (RIPs), currently classified as rRNA N-glycosylases (EC ). These activities were highest in seed; intermediate in flower bud, immature seed, sepal + gynoecium, leaf, and root; and very low in all other tissues.