recombinant chlorotoxin polypeptide  (Alomone Labs)

Journal: Cell Communication and Signaling : CCS

Article Title: Neuropilin-1 drives tumor-specific uptake of chlorotoxin

doi: 10.1186/s12964-019-0368-9

Figure Lengend Snippet: Structure of Cltx, ER-472 and related compounds. a , amino acid sequence of native Cltx which features 4 disulfide bonds, 3 lysine (K) and 3 arginine (R, in bold) residues, including amidated R at the C-terminus. b , structure of ER-472 PDC comprised of Cltx peptide linked via K27 to a novel cryptophycin analog (cytotoxic warhead), via a cleavable dimethyl disulfide linker. c , S-methyl cryptophycin, the active metabolite of ER-472 generated in tumor. d , ER-271 mimics ER-472 that lacks Cltx; composed of cryptophycin analog plus the dimethyl disulfide linker which terminates in an aryl group

Article Snippet: Recombinant Cltx expressed in E.coli (Cat# RTC-450 Alomone Labs, Jerusalem, Israel) has a carboxylated C-terminal arginine residue (Cltx-COOH).

Techniques: Sequencing, Generated

Journal: Cell Communication and Signaling : CCS

Article Title: Neuropilin-1 drives tumor-specific uptake of chlorotoxin

doi: 10.1186/s12964-019-0368-9

Figure Lengend Snippet: Cltx binds to NRP1 only when its C-terminal arginine is de-amidated; Cltx de-amidation occurs in tumor. Cltx-CONH 2 (native Cltx with amidated C-terminal arginine) does not bind to NRP1 at concentrations from 0 to 1750 nM ( a ) while Cltx-COOH (Cltx with a carboxylated C-terminal arginine) demonstrated dose responsive NRP1 binding with an affinity (K D ) of ~ 240 nM ( c ). Graphs are output from BLI assay with K D determined by octet data analysis software version 8.2; graphs are representative of multiple assays. b , peptides identified in PC-3 tumor lysate by MS analysis 1 h post dose of Cltx, in order of abundance. Peptides represented in black or red have amidated versus de-amidated C-terminal arginine residue respectively. Peptides 1 and 3 are full length Cltx with amidated (native) versus de-amidated C-terminal arginine respectively. d , VEGF binding to NRP1 (fixed concentration at 390 nM) was dose dependently inhibited in the presence of increasing concentration of Cltx-COOH (0 to 800 μM), R 2 = 0.98; suggests that Cltx binding to NRP1 occurs at VEGF binding site

Article Snippet: Recombinant Cltx expressed in E.coli (Cat# RTC-450 Alomone Labs, Jerusalem, Israel) has a carboxylated C-terminal arginine residue (Cltx-COOH).

Techniques: Binding Assay, Software, Residue, Concentration Assay

Journal: Cell Communication and Signaling : CCS

Article Title: Neuropilin-1 drives tumor-specific uptake of chlorotoxin

doi: 10.1186/s12964-019-0368-9

Figure Lengend Snippet: Binding of Cltx-derived peptides to NRP1. Cltx-derived peptides were generated through trypsin digest of full length native Cltx or by peptide synthesis. NRP1 binding was assessed by BLI; biotinylated peptides were attached to biosensors and evaluated for binding to NRP1 (0 to 1750 nM). Binding affinity data (K D ) represents mean of 2 to 6 independent experiments. ns = no significant binding

Article Snippet: Recombinant Cltx expressed in E.coli (Cat# RTC-450 Alomone Labs, Jerusalem, Israel) has a carboxylated C-terminal arginine residue (Cltx-COOH).

Techniques: Binding Assay, Generated