1. Luffangulin, a novel ribosome inactivating peptide from ridge gourd (Luffa acutangula) seeds
Hexiang Wang, Tzi Bun Ng Life Sci. 2002 Jan 11;70(8):899-906. doi: 10.1016/s0024-3205(01)01466-7.
A ribosome inactivating peptide, with an N-terminal sequence exhibiting pronounced similarity to that of the 6.5 kDa-arginine/glutamate-rich polypeptide from Luffa cylindrica seeds, was isolated from seeds of a closely related species, the ridge gourd Luffa acutangula. The 5.6 kDa-peptide designated luffangulin inhibited cell-free translation with an IC50 of 3.5 nM but lacked inhibitory activity toward HIV-1 reverse transcriptase. It was similar to luffaculin, the 28 kDa ribosome inactivating protein in being unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. On CM-cellulose luffangulin and luffaculin appeared as two adjacent peaks.
2. Hispin, a novel ribosome inactivating protein with antifungal activity from hairy melon seeds
T B Ng, A Parkash Protein Expr Purif. 2002 Nov;26(2):211-7. doi: 10.1016/s1046-5928(02)00511-9.
A ribosome inactivating protein demonstrating a molecular mass of 21 kDa and a novel N-terminal sequence was isolated from seeds of the hairy melon. The purification procedure involved affinity chromatography on Affi-gel blue gel and ion exchange chromatography on CM-Sepharose and Mono S. The protein designated hispin inhibited translation in the cell-free rabbit reticulocyte lysate system with an IC50 of 165 pM and exhibited N-glycosidase activity. Antifungal activity was also observed.
3. Purification and characterization of charantin, a napin-like ribosome-inactivating peptide from bitter gourd (Momordica charantia) seeds
A Parkash, T B Ng, W W Tso J Pept Res. 2002 May;59(5):197-202. doi: 10.1034/j.1399-3011.2002.00978.x.
A peptide designated charantin, with a molecular mass of 9.7 kDa, was isolated from bitter gourd seeds. The procedure comprised affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on Mono S and gel filtration on Superdex 75. The N-terminal sequence of charantin exhibited marked similarity to that of the 7.8-kDa napin-like peptide previously isolated from bitter gourd seeds. Charantin inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC50 of 400 nm, a potency lower than that of the previously reported small ribosome-inactivating protein gamma-momorcharin (IC50 = 55 nm) which also exhibited an abundance of arginine and glutamate/glutamine residues. Charantin reacted positively in the N-glycosidase assay, yielding a band similar to that formed by the small ribosome-inactivating proteins gamma-momorcharin and luffin S.
