Isolation and Molecular Characterization of Four Arginine/Glutamate Rich Polypeptides from the Seeds of Sponge Gourd (Luffa cylindrica)^†

Structural characterization and anti-HIV-1 activities of arginine/glutamate-rich polypeptide Luffin P1 from the seeds of sponge gourd (Luffa cylindrica)

“…The molar concentrations of proteins required for 50% inhibition of protein synthesis (IC 50 ) were: Luffin A, 5.4 nM; Luffin B, 19.8 nM; Luffin S, 0.34 nM; Luffin P1, 0.88 nM; 9K-PSI, 140 nM; Luffacylin, 0.14 nM. These small RIPs are characterized by a high content of arginine and glutamate residues and thus designated ARGPs (Ishihara et al, 1997). The N-terminal sequence of Luffin P1 exhibits a pronounced similarity to that of 7.8 kDa Luffacylin.…”

“…The N-terminal sequence of Luffin P1 exhibits a pronounced similarity to that of 7.8 kDa Luffacylin. In a separate study, four ARGPs with molecular weights of 5, 6.5, 12.5 and 14 kDa, respectively, have been isolated from L. cylindrica, but not assayed for translation inhibition activity (Ishihara et al, 1997). The 6.5k-ARGP has almost identical sequence with Luffin P1 except that the former has two extra residues Pro-Arg at the N-terminus and two extra residues Val-Asp at the C-terminus.…”

Primary Structure of 6.5k-Arginine/Glutamate-rich Polypeptide from the Seeds of Sponge Gourd (Luffa cylindrica)

“…Seeds of the sponge gourd were obtained from Takii Seed Co., Ltd. 6.5k-AGRP was purified by the procedures described in our previous paper 6 ) exeept that ion-exchange column chromatography on a CM-cellulose column was omitted. In brief, the pH 4.0 extract from the sponge gourd seeds was put onto a Sephadex G-75 column (5 x 140cm) and eluted with 50 mM sodium acetate buffer, pH 5.0.…”

“…5 ) Previously, Ishihara et al isolated four arginine/glutamate-rich polypeptides (AGRPs) with different molecular sizes, ranging from 5 kDa to 14 kDa from the sponge gourd (Luffa cylindrica) seeds and analyzed them with respect to amino acid composition, N-terminal sequence, and localization in protein bodies. 6 ) To examine the function(s) of AGRPs in the sponge gourd seeds, we have sought to establish their detailed primary structures. In this study, we determined the complete amino acid sequence of 6.5k-AGRP and discuss its sequence similarity to other known protein sequences.…”

A novel recombinant immunotoxin with the smallest ribosome‐inactivating protein Luffin P1: T‐cell cytotoxicity and prolongation of allograft survival

“…In 1994, Gao et al reported the discovery of a novel small RIP, Luffin‐S, from the seeds of the plant Luffa cylindrica [6]. Since then, quite a number of small RIPs (<10 kD) have been discovered from various plants [7–9]. The smallest member of this new family, Luffin P1, has a molecular weigh of 5226.8 Da, yet possessing a highly potent inhibitory activity on protein synthesis in the cell‐free rabbit reticulocyte lysate with IC50 of 0.88 nM [10, 11].…”