New ribosome-inactivating proteins with polynucleotide:adenosine glycosidase and antiviral activities from Basella rubra L. and Bougainvillea spectabilis Willd.

Abstract

New single-chain (type 1) ribosome-inactivating proteins (RIPs) were isolated from the seeds of Basella rubra L. (two proteins) and from the leaves of Bougainvillea spectabilis Willd. (one protein). These RIPs inhibit protein synthesis both in a cell-free system, with an IC50 (concentration causing 50% inhibition) in the 10(-10) M range, and by various cell lines, with IC50S in the 10(-8)-10(-6) M range. All three RIPs released adenine not only from rat liver ribosomes but also from Escherichia coli rRNA, polyadenylic acid, herring sperm DNA, and artichoke mottled crinkle virus (AMCV) genomic RNA, thus being polynucleotide:adenosine glycosidases. The proteins from Basella rubra had toxicity to mice similar to that of most type 1 RIPs (Barbieri et al., 1993, Biochim Biophys Acta 1154: 237-282) with an LD50 (concentration that is 50% lethal) < or = 8 mg.kg-1 body weight, whilst the RIP from Bougainvillea spectabilis had an LD50 > 32 mg.kg-1. The N-terminal sequence of the two RIPs from Basella rubra had 80-93% identity, whereas it differed from the sequence of the RIP from Bougainvillea spectabilis. When tested with antibodies against various RIPs, the RIPs from Basella gave some cross-reactivity with sera against dianthin 32, and weak cross-reactivity with momordin I and momorcochin-S, whilst the RIP from Bougainvillea did not cross-react with any antiserum tested. An RIP from Basella rubra and one from Bougainvillea spectabilis were tested for antiviral activity, and both inhibited infection of Nicotiana benthamiana by AMCV.

Sand fly feeding on noxious plants: a potential method for the control of leishmaniasis.

“…17,18 Solanaceous alkaloids are also toxic to insects and a ribosomeinactivating protein was found in a Bougainvillea species similar to the one used in our experiments. [19][20][21] The plant species used in the experiments are exotic, and it is not surprising that the lethal effect that B. glabra exerts in relatively small areas was not a sufficient selective pressure to make this plant repellent to P. papatasi. According to earlier findings and the present evidence, R. communis may also be effective against both P. papatasi and L. major.…”

Ribosome-inactivating and Adenine Polynucleotide Glycosylase Activities in Mirabilis jalapa L. Tissues

“…Poly(A), genomic RNA from tobacco mosaic virus (TMV), and rRNA from Escherichia coli (16 S ϩ 23 S, M r ϭ 1.75 ϫ 10 6 ) were from Roche Molecular Biochemicals (Mannheim, Germany). Cell culture medium and supplements and all other chemicals were as described in previous work (18). Sera against various RIPs were a gift from Dr. P. Strocchi (University of Bologna).…”

“…This may allow the classification of the two different pairs as different classes of RIPs, as happens in S. officinalis (14). All isoforms have little similarity to bouganin, a RIP isolated from Bougainvillea spectabilis, another member of the Nyctaginaceae family (18). Work is in progress to verify whether MAP-4 has enzymatic and substrate specificities different from those of MAP.…”

Isolation of Antidiabetic Principle from <i>Bougainvillea spectabilis</i> Willd (Nyctaginaceae) Stem Bark

“…Bougainvillea spectabilis Willd is commonly known Bougainvillea, Great Bougainvillea with the local Indian names as Booganbel, Cherei, Baganbilas, Booganvel, Bouganvila, Kagithala Puvvu [4]. Phytoconstituents such as flavonoids, phenolic compounds, antiviral [5], ribosome inactivating protein [6], amylase inhibitors [7], oxidase [8] and pinitol [9] have been isolated from B. spectabilis.…”