Bryodin, a ribosome-inactivating protein from the roots of Bryonia dioica L. (white bryony)

Abstract

Bryodin is a strongly basic (pI greater than or equal to 9.5) glycoprotein (neutral sugar content 6.3%) with Mr 30,000, purified from the roots of Bryonia dioica (white bryony). This protein inhibits protein synthesis by a rabbit reticulocyte lysate with and ID50 (concentration causing 50% inhibition) of 0.12 nM (3.6 ng/ml) and has much less effect on protein synthesis by whole cells, with ID50 values ranging from 46 nM to 2.27 microM (1.4-67 micrograms/ml). Bryodin acts by inactivating ribosomes, with a less-than-equimolar ratio, which suggests a catalytic action. Bryodin decreases the number of local lesions induced by tobacco mosaic virus in the leaves of Nicotiana glutinosa. From all its properties, bryodin can be considered to be a ribosome-inactivating protein, similar to those already known [reviews: Barbieri & Stirpe (1982) Cancer Surveys 1, 489-520; Stirpe & Barbieri (1986) FEBS Lett. 195, 1-8].

The Aspergillus toxin restrictocin is a suitable cytotoxic agent for generation of immunoconjugates with monoclonal antibodies directed against human carcinoma cells

“…After treatment no consistent loss of protein synthesis inhibition activity of restrictocin was observed (see Fig. 1) while the reported activity after derivatization of Pseudomonas exotoxin A and bryodin was around 40% ofthe original activity [35,36]. Later data further support the suitability of restrictocin for immunoconjugate preparation.…”

A systemic antiviral resistance‐inducing protein isolated from Clerodendrum inerme Gaertn. is a polynucleotide:adenosine glycosidase (ribosome‐inactivating protein)

“…In some cases the antiviral activity, but not the systemic resistance induction, was due to proteins which were provisionally named ribosome-inactivating proteins (RIPs, review in [2]). Some proteins with antiviral activity were indeed found to be RIPs [3] and, conversely, the antiviral activity in plant extracts led to the identification of some new RIPs [4]. Recently two basic glycoproteins, called CIP-29 and CIP-34, which induced a very high degree of systemic resistance against tobacco mosaic virus in Nicotiana tabacum cv.…”

Identification of a specific tyrosine residue in Bryodin 1 distinct from the active site but required for full catalytic and cytotoxic activity

“…Keywords: bryodin; immunotoxin; membrane interaction; mutagenesis; ribosome-inactivating protein Bryodin-1 (BDI), a type 1 RIP isolated from Bryonia dioica (Stirpe et al, 1986), may have a therapeutic advantage over other RIPs due to its lower toxicity in vivo (Siegall et al, 1994). Type 1 RIPs have a common N-glycosidase activity, a basic isoelectric point, and molecular mass of 26-30 kDa (Barbieri et al, 1993).…”

“…These data indicate that Y141 plays an important role in the enzymatic activity of BDI and that Y140, although not essential for catalytic activity, is required for full BDI function. Because residues 140 and 141 are distinct from residues implicit in the active site, they may be involved in ribosomal and/or membrane interactions or in intracellular trafficking of the toxin and immunotoxin.Keywords: bryodin; immunotoxin; membrane interaction; mutagenesis; ribosome-inactivating protein Bryodin-1 (BDI), a type 1 RIP isolated from Bryonia dioica (Stirpe et al, 1986), may have a therapeutic advantage over other RIPs due to its lower toxicity in vivo (Siegall et al, 1994). Type 1 RIPs have a common N-glycosidase activity, a basic isoelectric point, and molecular mass of 26-30 kDa (Barbieri et al, 1993).…”