Glycosylated cell-penetrating peptides and their conjugates to a proapoptotic peptide: preparation by click chemistry and cell viability studies

Abstract

Cell-penetrating peptides (CPPs), which are usually short basic peptides, are able to cross cell membranes and convey bioactive cargoes inside cells. CPPs have been widely used to deliver inside cells peptides, proteins, and oligonucleotides; however, their entry mechanisms still remain controversial. A major problem concerning CPPs remains their lack of selectivity to target a specific type of cell and/or an intracellular component. We have previously shown that myristoylation of one of these CPPs affected the intracellular distribution of the cargo. We report here on the synthesis of glycosylated analogs of the cell-penetrating peptide (R6/W3): Ac-RRWWRRWRR-NH 2 . One, two, or three galactose(s), with or without a spacer, were introduced into the sequence of this nonapeptide via a triazole link, the Huisgen reaction being achieved on a solid support. Four of these glycosylated CPPs were coupled via a disulfide bridge to the proapoptotic KLAK peptide, (KLAKLAKKLAKLAK), which alone does not enter into cells. The effect on cell viability and the uptake efficiency of different glycosylated conjugates were studied on CHO cells and were compared to those of the nonglycosylated conjugates: (R6/W3)S-S-KLAK and penetratinS-S-KLAK. We show that glycosylation significantly increases the cell viability of CHO cells compared to the nonglycosylated conjugates and concomitantly decreases the internalization of the KLAK cargo. These results suggest that glycosylation of CPP may be a key point in targeting specific cells.

In silico study of peptide inhibitors against BACE 1

“…This may help in their further design as previous reports shows the correlation between glycosylation sites and anti-bacterial activity in peptides (Strub et al 1996). The functional sites can also help in conjugating these peptides with carbohydrates by the help of the newly emerging click chemistry protocols (Li et al 2013) thereby altering the bioavailability of the peptides (Dutot et al 2009). …”

Transduction of Human Recombinant Proteins into Mitochondria as a Protein Therapeutic Approach for Mitochondrial Disorders

“…β-galactosidase was dissolved in PBS, treated with iodoacetamide, esterified with 4-(maleimidomethyl)-cyclohexanecarboxylic acid N-hydroxysuccinimide ester and cross-linked with the TAT peptide. Conjugation chemistry gives either stable linkage or creates thioester bridges to be cleaved under reducing conditions, thus releasing the desired cargo (124,147).…”

Glycosylated Cell‐Penetrating Peptides (GCPPs)

“…[92,93] Galectins have been reported as indicators for malignanciesi ns tomach, [94] liver, [95] and colon cancer. [103] However,t hese interesting seminals tudies with glycosylatedc ell-penetrating peptides (GCPPs) were restricted to the galactose pendant and Chineseh amster ovary cell line. [99] N-Acetylglucosamine (GlcNAc) is ac omponent of glycoproteins, proteoglycans, GAGs, and bacterial and fungalc ell walls, and it can be appliedt oi nduce immunity responses.…”