Membrane permeant peptides

Zolotarevsky Y, Hecht G, Koutsouris A, Gonzalez DE, Quan C, Tom J, Mrsny RJ, Turner JR (2002) A membrane-permeant peptide that inhibits MLC kinase restores barrier function in in vitro models of intestinal disease. Gastroenterol 123 163-172... 

What is the difference between a membrane permeant peptide and a pore-forming peptide ... 

Membrane permeant peptide Gationic peptides capable of breaching the biological membrane without causing cell lysis. 

Dostmann WR et al. (2000) Highly specific, membrane-permeant peptide blockers of cGMP-dependent protein kinase la inhibit NO-induced cerebral dilation. Proc Natl Acad Sci USA 97 14772-14777... 

The same FRET pair was used to create a probe to monitor cathe-psins in HeLa cells [94], Since cathepsins are important in proteolysis within endosomes, it was in this case crucial to make the probe membrane-permeant. For this purpose a nona-arginine peptide was coupled to the N terminus to allow for endocytotic uptake. 

When REFs were exposed to the membrane-permeant PKA activator, 8-(4-chlorophenylthio)-cAMP (CPT-cAMP), they underwent the same morphological transformation as described above (disruption of actin stress fibers leading to cell shape changes). In contrast, cells microinjected with the caged peptide (5 pM estimated intracellular concentration) and exposed to UV irradiation were unable to respond to the CPT-cAMP stimulus, demonstrating that the CPT-cAMP activation of the PKA pathway had been efficiently blocked in vivo by the decaged peptide [152],... 

Bullok, K. Piwnica-Worms, D. Synthesis and characterization of a small, membrane-permeant, caspase-activatable far-red fluorescent peptide for imaging apoptosis. J. Med. Chem. 2005, 48, 5404-5407. 

Membrane destabilization can be simultaneously monitored by using propidium iodide. This non fluorescent and poorly permeant small molecule enters into the cells only upon membrane permeabilization/ destabilization and becomes fluorescent upon binding to DNA in the nucleus. In the presence of melittin, cells are also rapidly (200 s) red-labeled upon peptide induced membrane permeabilization (Figure 16.4D). It can be seen that the diffusion of propidium iodide inside the cells is correlated with the leak of EGFP. The results show that melittin induces the formation of pores in the plasma membranes allowing the passage of... 

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