Peptides useful as cell-penetrating peptides

Abstract

A method of penetrating a cell where the cell is contacted with a complex that includes (A) a peptide comprising at least 8 consecutive amino acids of the human lactoferrin protein or of the bovine lactoferrin protein; and (B) a cargo molecule bound to the peptide.

1 . (canceled) 
     
     
         2 . A method of penetrating a cell, comprising contacting a cell with a complex, comprising:
 (A) a peptide comprising at least 8 consecutive amino acids of the human lactoferrin protein or of the bovine lactoferrin protein; and   (B) a cargo molecule bound to the peptide.   
     
     
         3 . The method of  claim 2 , wherein the cargo molecule is a small molecule having a molecular weight of 1000 D or less and is a drug or a drug candidate bound to the peptide. 
     
     
         4 . The method of  claim 2 , wherein the peptide comprises SEQ ID NO:3. 
     
     
         5 . The method of  claim 2 , wherein the peptide consists of SEQ ID NO:3. 
     
     
         6 . The method of  claim 2 , wherein the peptide is labeled with a detectable marker selected from the group consisting of a radioactive label, a fluorophore, and a hapten 
     
     
         7 . The method of  claim 2 , wherein the cargo molecule is covalently bound to the peptide. 
     
     
         8 . The method of  claim 2 , wherein the cargo molecule is non-covalently bound to the peptide. 
     
     
         9 . The method of  claim 2 , wherein the cargo molecule is at least one selected from the group consisting of a nucleic acid, an amino acid, a peptide, a protein, a carbohydrate, a lipid, and a small molecule. 
     
     
         10 . The method of  claim 2 , wherein the cargo molecule is present as or part of a structure,
 wherein the structure is selected from the group consisting of nanoparticles, microparticles, liposomes, and micelles.   
     
     
         11 . The method of  claim 2 , wherein cargo molecule is a nucleic acid selected from the group consisting of DNA molecules, RNA molecules, PNA molecules, siRNA molecules, antisense molecules, ribozymes, aptamers, spiegelmers, and decoy molecules. 
     
     
         12 . The method of  claim 2 , wherein the cargo molecule is a peptide intended for use as a vaccine. 
     
     
         13 . The method of  claim 2 , wherein the cargo molecule is a nucleic acid-based vaccine. 
     
     
         14 . The method of  claim 2 , wherein the peptide is radioactively labeled. 
     
     
         15 . The method of  claim 2 , wherein the peptide is labeled with fluorophore, and or a hapten. 
     
     
         16 . The method of  claim 2 , wherein the peptide is radioactively labeled, wherein the radioactively label is a radioactively labeled amino acid. 
     
     
         17 . The method of  claim 16 , wherein the radioactively labeled amino acid is a tritium-labeled amino acid. 
     
     
         18 . The method of  claim 2 , wherein the peptide is labeled with a hapten and the hapten is biotin.