Modifications of peptide compositions to increase stability and delivery efficiency

Abstract

The disclosed invention relates to methods of modifying peptide compositions to increase stability and delivery efficiency. Specifically, the disclosed invention relates to methods to increase the stability and delivery efficiency of protein kinase C (PKC) modulatory peptide compositions. A “therapeutic peptide composition” comprises a “carrier peptide” and a “cargo peptide.” A “carrier peptide” is a peptide or amino acid sequence within a peptide that facilitates the cellular uptake of the therapeutic peptide composition. The “cargo peptide” is a PKC modulatory peptide. Peptide modifications to either the carrier peptide, the cargo peptide, or both, which are described herein increase the stability and delivery efficiency of therapeutic peptide compositions by reducing disulfide bond exchange, physical stability, reducing proteolytic degradation, and increasing efficiency of cellular uptake.

We claim: 
     
         1 . A protein kinase C (PKC) modulatory peptide conjugate, comprising:
 a PKC modulatory peptide covalently linked to an intracellular carrier peptide, wherein the intracellular carrier peptide, the modulatory peptide, or both are modified at the N-terminus, and   a pharmaceutically acceptable excipient.   
     
     
         2 . The conjugate of  claim 1 , wherein the PKC modulatory peptide is an inhibitory peptide which inhibits activity of a PKC isozyme or an activator peptide which promotes activity of a PKC isozyme. 
     
     
         3 . The conjugate of  claim 1 , wherein the intracellular carrier peptide is a modified tat peptide comprising YGRKKRRQRRR (SEQ ID NO: 166) or a modified tat peptide comprising CYGRKKRRQRRR (SEQ ID NO: 164). 
     
     
         4 . The conjugate of  claim 3 , wherein the modified tat peptide is substituted at its N-terminal end by an acyl, alkyl, or sulfonyl group. 
     
     
         5 . The conjugate of  claim 4 , wherein the modified tat peptide is acylated at its N-terminal end. 
     
     
         6 . The conjugate of  claim 1 , wherein the tat peptide is further modified at its C-terminal end. 
     
     
         7 . The conjugate of  claim 1 , wherein the tat peptide is further modified by formation of an amide at its C-terminal end. 
     
     
         8 . The conjugate of  claim 1 , wherein the PKC modulatory peptide is covalently linked to a side chain of an amino acid of the modified tat peptide. 
     
     
         9 . The conjugate of  claim 1 , wherein the PKC modulatory peptide is covalently linked to a side chain of a residue selected from cysteine, lysine, and tyrosine. 
     
     
         10 . The conjugate of  claim 3 , wherein the PKC modulatory peptide is covalently linked to a side chain of the N-terminal cysteine residue of the modified tat peptide comprising CYGRKKRRQRRR (SEQ ID NO: 164). 
     
     
         11 . The conjugate of  claim 10 , wherein the N-terminal cysteine of the tat peptide is acylated. 
     
     
         12 . The conjugate of  claim 10 , wherein the C-terminal arginine of the tat peptide is a primary carboxamide. 
     
     
         13 . The conjugate of  claim 10 , wherein the PKC modulatory peptide is modified by either acylation at its N-terminal end, or amidation at its C-terminal end, or by both acylation at its N-terminal end and amidation at its C-terminal end. 
     
     
         14 . The conjugate of  claim 10 , wherein the PKC modulatory peptide is covalently linked to the tat peptide through the sulfhydryl group of the cysteine residue of the tat peptide. 
     
     
         15 . The conjugate of  claim 1 , which further comprises a second carrier peptide. 
     
     
         16 . A linear therapeutic peptide, comprising:
 a carrier peptide and a PKC activity modulating cargo peptide, wherein the carrier peptide and the cargo peptide are linked by a peptide bond.   
     
     
         17 . The linear therapeutic peptide of  claim 16 , further comprising a linker peptide positioned between the carrier peptide and the cargo peptide, wherein the carrier peptide and the cargo peptide are linked to the linker peptide by a peptide bond. 
     
     
         18 . A therapeutic peptide multimer, comprising:
 at least one carrier peptide conjugated to a plurality of PKC activity modulating cargo peptides.   
     
     
         19 . The therapeutic peptide multimer of  claim 18 , wherein the at least one carrier protein comprises a first and a second cysteine residue. 
     
     
         20 . The therapeutic peptide multimer of  claim 19 , wherein a first cargo peptide is linked to the first cysteine residue by a disulfide bond and a second cargo protein is linked to the second cysteine residue by a disulfide bond.