The plant ribosome inactivating proteins luffin and saporin are potent inhibitors of HIV‐1 integrase

Abstract

The ribosome inactivating proteins (RIPs) are a group of proteins that are able to inactivate eukaryotic protein synthesis by attacking the 28S ribosomal RNA. Recent studies have shown that some RIPs possess strong anti-human immunodeficiency virus (HIV) activity. In this study, several common plant RIPs including agrostin, gelonin, luffin,L-momorcharin, saporin and trichosanthin were examined for the ability to interfere with HIV-1 replication in a variety of mechanistic assays in vitro. These assays included the CD4/gp120 interaction assay, HIV-1 reverse transcriptase (RT) assay, HIV-1 protease assay and HIV-1 integrase assay. At the concentration of 100 nM, all RIPs appeared to enhance the CD4/ gp120 interaction by about 50%. These RIPs exhibited a very weak suppressive effect on HIV-1 RT and on HIV-1 protease. In contrast, with the exception of agrostin, all the RIPs tested could strongly inhibit HIV-1 integrase, the extent of inhibition ranging from 26.1 to 96.3% in an ELISA-based assay. Two RIPs, saporin and luffin, which licited over 90% inhibition in the ELISA-based assay, were further characterized in a radiometric assay. Both of these two RIPs evoked a strong dose-dependent inhibition in the 3P P-end processing and strand-transfer activities of integrase. The results from this study suggest that the anti-HIV property of RIPs may be due to inhibition of HIV-1 integrase.z 2000 Federation of European Biochemical Societies.

Intestinal Shiga Toxin-Producing Escherichia coli Bacteria Mitigate Bovine Leukemia Virus Infection in Experimentally Infected Sheep

“…The mechanism of Stx antiviral effects was beyond the scope of this study, but antiviral properties of RIPs are not necessarily limited to rRNA depurination. For example, some RIPs have activity against reverse transcriptase and other viral proteins (2,38,54), but such activities have yet to be described for Stxs.…”

Purification and characterization of Moschatin, a novel type I ribosome-inactivating protein from the mature seeds of pumpkin (Cucurbita moschata), and preparation of its immunotoxin against human melanoma cells

“…They are shown to have diversified biological functions, such as antiviral (anti-HIV), antifungal and insecticidal properties [3][4][5][6]. They are rRNA N-glycosidase that site-specifically cleaves the N-glycosidic bond of a specific adenosine residue (A 4324 ) in a highly conserved loop (the sarcin/ricin domain) of the largest ribosomal RNA.…”

In Vitro Root Culture From Roots And Leaf Explants Of Luffa Acutangula(L.) Roxb

“…Luffin, a ribosome inactivating protein isolated from this plant is used to prepare immunotoxins by conjugation to mono clonal antibodies. It is also reported to possess antiviral properties (Au et al, 2000).Other than these therapeutic values, the plant possess analgesic activity and antioxidant potential (Naresh Singh Gill et al, 2011), hypoglycemic activity (Jural et al, 2008) and hepato protective activity (Jadhav et al, 2010).…”