Design and synthesis of a novel peptide for selective detection of cancer cells

Abstract

Using a minimalist approach, an 11-residue peptide (Peptide 1) tagged with rhodamine fluorophore was designed and synthesized for selective detection of cancer cells. Peptide 1 contains RGD and NGR motifs to bind, respectively, integrins and aminopeptidase CD13, which are over expressed in cancer cells. Surface tension measurements revealed that peptide 1 possess surface-active property owing to the overall hydrophobicity and cationic nature of the peptide. Peptide 1 displays cancer cell-selective binding at ≤5.0 µM concentrations, while peptide 2 (randomized sequence of 1) shows non-selective binding to normal and cancer cells. Fluorescence microscopy and FACS analysis demonstrated the intracellular localization of peptide 1 in three different cancer cell lines, confirming the role of RGD and NGR motifs.Cytotoxicity assay exhibited the viability of normal and cancer cells up to 100 µM concentrations of peptide 1. Steady-state fluorescence measurements disclosed the preferential interactions of the peptide 1 with anionic POPC/POPG bilayers rather than with zwitterionic POPC lipid bilayers. Circular dichroism studies showed minimal changes in the secondary structure of peptide 1 upon binding with the anionic lipid bilayers. Peptide 1 is largely unordered, non-toxic, and useful for identification of cancer cells. Peptide 1 provides a template for designing drug-loaded peptides for targeted delivery into cancer cells. K E Y W O R D Scell-selective binding, fluorescence, peptide synthesis, peptide-membrane interactions, surface activity, targeting cancer cells | 611 RAJAVENKATESH et al.

Design, Synthesis, and Anticancer Activity of N‐1 Terminal Segment of α‐(2, 5,7‐Tri‐tert‐butylindol‐3‐yl)alanine‐Incorporated Short Peptides

“…This concludes that, P1 and P2 are surface active (P2 < P1), and upon addition of 10.0 μM, the surface tension of Tris buffer decreased by 10.42 mN/m and 8.45 mN/m respectively. [56]…”

“…The electrostatic interaction between the anionic membrane (POPC : POPG) and the zwitterionic membrane (POPC), as suggested by extensive studies on the mechanism of killing bacteria and cancer cells by membrane-active peptides, would be a crucial element in eliciting their antibacterial and anticancer activity. [56,57] So, using tiny unilamellar vesicles (lipid bilayer membranes) made of POPC and a POPC : POPG (1 : 1) mixture, we studied the selective layer interactions of peptides P1 and P2 (10.0 μM). [57] To test the binding affinity of peptides towards zwitterionic POPC and anionic POPC : POPG (1 : 1) vesicles and fluorescence which contains both native and modified tryptophan (P1 and P2) (Figure 6).…”

Synthesis, docking studies, in vitro cytotoxicity evaluation and DNA damage mechanism of new tyrosine‐based tripeptides

“…Peptides have features such as small structures, easy synthesis, and the ability to affect tumors, which have made these compounds an important position in potential cancer drug research. [10,[39][40][41][42][43][44][45][46] In cancer treatment, peptides are preferred as tumor-targeting agents (hormones, vaccines, and radionuclides) as well as their direct use as cytotoxic drugs. [3,7,47] The ability of peptides to bind to different receptors and be a part of various biochemical pathways allows them to function as potential diagnostic tools and biomarkers.…”

Recent research progress of biologically active peptides

“…153 Rajavenkatesh et al used a minimal method to design and synthesize an 11-residual peptide labeled rhodamine fluorophore for the selective detection of cancer cells. 154 Organic anion-transporting polypeptides are polysexual organic anion transporters expressed in the blood-brain barrier, veins, and other organs. 155 Kim et al isolated and screened cell-penetrating peptide (CPP) rich in hydrophobic residues, which showed a more effective cell uptake rate than traditional CPP, low cytotoxicity, and strong stability.…”

“…Rajavenkatesh et al used a minimal method to design and synthesize an 11‐residual peptide labeled rhodamine fluorophore for the selective detection of cancer cells 154 . Organic anion‐transporting polypeptides are polysexual organic anion transporters expressed in the blood–brain barrier, veins, and other organs 155 .…”