Lipidated peptides as anti-obesity agents

Abstract

Lipidated peptides, analogs of both forms of the prolactin-releasing peptide. PrRP31 and PrRP20, represent anorexigenic compounds that lower food intake and function in the brain after peripheral administration. The analogs PrRP31 and PrRP20 lipidated at the N-terminus by myristic or palmitic acids bind with high affinity to the endogenous receptor GPR10 in the rat pituitary cell line RC-4B/C and CHO cell line with transfected human receptor. These lipidated peptides also significantly decrease, in a dose-dependent manner, the food intake in fasted mice and have similar effects in comparable doses as centrally administered natural PrRP31, these effects are, however, stronger and longer lasting. Lipidation of an effective anorexigenic neuropeptide PrRP induces a central effect after peripheral administration and thus makes the lipidated analogs of PrRP a promising anti-obesity drug.

1 - 20 . (canceled) 
     
     
         21 : A method of lowering food intake in a subject, the method comprising administering a lipidated analog of prolactin-releasing peptide to the subject, wherein the lipidated analog of prolactin-releasing peptide is according to a formula:
   J 1 -J 2 - r RP s GR t -NH 2   (I);
   wherein:   J 1  represents a fatty acid C6 to C18 bound by an amide bond to an amino group of an N-terminal amino acid;   J 2  represents a chain of 13 or 24 amino acids;   r is isoleucine, alanine, or phenylglycine;   s is valine or phenylglycine; and   t is phenylalanine or an amino acid with a side chain containing CH 2 —Ar or CH 2 —S—CH 2 —Ar, wherein Ar represents phenyl or naphtyl, optionally substituted by a halogen or nitro group.   
     
     
         22 : The method of  claim 21 , wherein t is selected from the group: naphtylalanine, benzylcystein, benzylhistidine, pentafluorophenylalanine, and nitrophenyalanine. 
     
     
         23 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is according to the formula:
   J 1 - k -J 3 - r RP s GR t -NH 2   (II), wherein
   J 1  represents a fatty acid C6 to C18 bound by an amide bond to an amino group of a N-terminal amino acid;   k is chosen from serine, threonine or diaminopropionic acid;   J 3  represents a chain of 23 or 12 amino acids;   r is isoleucine, alanine, or phenylglycine;   s is valine or phenylglycine; and   t is phenylalanine or an amino acid with a side chain containing CH 2 —Ar or CH 2 —S—CH 2 —Ar, where Ar represents phenyl or naphtyl, optionally substituted by halogen or nitro group.   
     
     
         24 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is according to the formula:
   J 1 - k R m H n HS q EuRTPDINPAWY mo R pr RP s GR t -NH 2   (III);
   wherein:   k is serine, threonine or diaminopropionic acid;   m is chosen from threonine, alanine or methylalanine;   n is glutamine or arginine;   q is methionine or norleucine;   u is threonine or isoleucine;   o is glycine or serine;   p is glycine, alanine, proline or N-methylglycine;   r is isoleucine, alanine or phenylglycine;   s is valine or phenylglycine;   t is phenylalanine or an amino acid with a side chain containing CH 2 —Ar or CH 2 —S—CH 2 —Ar, where Ar represents phenyl or naphtyl, optionally substituted by halogen or nitro group; and   J 1  represents a fatty acid C6 to C18 bound by the amide bond to the amino group of the N-terminal amino acid.   
     
     
         25 : The method of  claim 21 , wherein the fatty acid is a C13-C18 fatty acid. 
     
     
         26 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is according to the formula:
   J 1 - k R m H n HS q EuRTPDINPAWY mo R pr RP s GR t -NH 2   (III), and
     J 1 -TPDINPAWY mo R pr RP s GR t -NH 2   (IV);
   wherein:   k is serine, threonine or diaminopropionic acid;   m is threonine, alanine or methylalanine;   n is glutamine or arginine;   q is methionine or norleucine;   u is threonine or isoleucine;   o is glycine or serine;   p is glycine, alanine, proline or N-methylglycine;   r is isoleucine, alanine or phenylglycine;   s is valine or phenylglycine;   t is phenylalanine or an amino acid with side chain containing CH 2 —Ar or CH 2 —S—CH 2 —Ar, where Ar represents phenyl or naphtyl, optionally substituted by halogen or nitro group; and   J 1  represents a fatty acid C6 to C18 bound by the amide bond to the amino group of the N-terminal amino acid.   
     
     
         27 : The method of  claim 26 ,
 wherein the binding affinity of said lipidated analog of prolactin-releasing peptide towards GPR10 receptor expressed in rat hypophyseal cells is not higher than 10 −6  mol·l −1 .   
     
     
         28 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is according to the formula:
   J 1 -SR m H n HS q EuRTPDINPAWY mo R pr RP s GR t -NH 2   (V);
   wherein:   m is threonine, alanine or methylalanine;   n is glutamine or arginine;   q is methionine or norleucine;   u is threonine or isoleucine;   o is glycine or serine;   p is glycine, alanine, proline or N-methylglycine;   r is isoleucine, alanine or phenylglycine, s is chosen from valine or phenylglycine;   t is phenylalanine or an amino acid with side chain containing CH 2 —Ar or CH 2 —S—CH 2 —Ar, where Ar represents phenyl or naphtyl, optionally substituted by halogen or nitro group; and   J 1  represents a fatty acid C6 to C18 bound by an amide bond to the amino group of the N-terminal amino acid.   
     
     
         29 : A method of preventing or treating obesity in a subject, the method comprising administering the lipidated analog of prolactin-releasing peptide according to  claim 21 . 
     
     
         30 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is selected from the group consisting of:
 Dpr(oct))RmHnHSNleETRTPDINPAWYmoRGrRPsGRF-NH 2 ;   (Dpr(dodec))RmHnHSNleETRTPDINPAWYmoRGrRPsGRF-NH 2 ;   (Dpr(tridec))RmHnHSNleETRTPDINPAWYmoRGrRPsGRF-NH 2 ;   (Dpr(myr))RmHnHSNleETRTPDINPAWYmoRGrRPsGRF-NH 2 ;   (Dpr(palm))RmHnHSNleETRTPDINPAWYmoRGrRPsGRF-NH 2 ;   (myr)TPDINPAWYmoRGrRPsGRF-NH 2 ;   (palm)TPDINPAWYmoRGrRPsGRF-NH 2 ;   (Dpr(oct))RmHnHSNleETRTPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   (Dpr(dodec))RmHnHSNleETRTPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   (Dpr(tridec))RmHnHSNleETRTPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   (Dpr(myr))RmHnHSNleETRTPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   (Dpr(palm))RmHnHSNleETRTPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   (myr)TPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ; and   (palm)TPDINPAWYmoRGrRPsGR 1-Nal-NH 2 ;   wherein:   m is threonine or alanine;   n is glutamine or arginine;   o is glycine or serine;   r is isoleucine, alanine or phenylglycine; and   s is valine or phenylglycine.   
     
     
         31 : The method of  claim 30 :
 wherein the binding affinity of said lipidated analog of prolactin-releasing peptide towards GPR10 receptor expressed in rat hypophyseal cells is not higher than 10 −6  mol·l −1 .   
     
     
         32 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is selected from the group consisting of:
 (Dpr(oct))RmHnHSNleETRTPDINPAWYmoRGIRPVGRF-NH 2 ;   (Dpr(dodec))RmHnHSNleETRTPDINPAWYmoRGIRPVGRF-NH 2 ;   (Dpr(tridec))RmHnHSNleETRTPDINPAWYmoRGIRPVGRF-NH 2 ;   (Dpr(myr))RmHnHSNleETRTPDINPAWYmoRGIRPVGRF-NH 2 ;   (Dpr(palm))RmHnHSNleETRTPDINPAWYmoRGIRPVGRF-NH 2 ;   (myr)TPDINPAWYmoRGIRPVGRF-NH 2 ;   (palm)TPDINPAWYmoRGIRPVGRF-NH 2 ;   (Dpr(oct))RmHnHSNleETRTPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   (Dpr(dodec))RmHnHSNleETRTPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   (Dpr(tridec))RmHnHSNleETRTPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   (Dpr(myr))RmHnHSNleETRTPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   (Dpr(palm))RmHnHSNleETRTPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   (myr)TPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ; and   (palm)TPDINPAWYmoRGIRPVGR 1-Nal-NH 2 ;   wherein:   m is threonine or alanine;   o is glycine or serine; and   n is glutamine or arginine.   
     
     
         33 : The method of  claim 32 ,
 wherein the binding affinity of said lipidated analog of prolactin-releasing peptide towards GPR10 receptor expressed in rat hypophyseal cells is not higher than 10 −6  mol·l −1 .   
     
     
         34 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is selected from the group consisting of:
 J a -SRAHQHSMETRTPDINPAWYTGRGIRPVGRF-NH 2 ;   J a -SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NH 2 ;   (N-palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NHMe;   (N-palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NOMe;   (N-myr)-TPDINPAWYTGRGIRPVGRF-NH 2 ;   (N-myr)-TPDINPAWYASRGIRPVGRF-NH 2 ;   (N-oct)-TPDINPAWYASRGIRPVGRF-NH 2 ;   (N-dec)-TPDINPAWYASRGIRPVGRF-NH 2 ;   (N-dodec)-TPDINPAWYASRGIRPVGRF-NH 2 ;   J 1′ -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGRF-NH 2 ;   J a -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGR 1-Nal-NH 2 ;   J a -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGR PheCl 2 —NH 2 ;   J a -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGR PheNO 2 —NH 2 ;   J a -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGR PheF 5 —NH 2 ;   J a -SRAHQHS Nle ETRTPDINPAWYTGRGIRPVGRY-NH 2 ;   J a -SRAHRHS Nle EIRTPDINPAWYASRGIRPVGRY-NH 2 ;   (N-myr)-Nle-ETRTPDINPAWYTGRGIRPVGRF-NH 2 ;   (N-myr)-QHSMETRTPDINPAWYTGRGIRPVGRF-NH 2 ;   (N-myr)-QHSMETRTPDINPAWYASRGIRPVGRF-NH 2 ; and   (N-palm)SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NOMe;   wherein:   J 1 =J 1′  or J a ;   J 1′  is palmitic acid, myristic acid or stearic acid; and   J a  is palmitic acid or myristic acid.   
     
     
         35 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is according to the formula:
   J 1 -TPDINPAWY mo RGIRPVGRF-NH 2 ;   wherein:   J 1  is palmitic acid or myristic acid;   m is threonine or alanine; and   o is glycine or serine.   
     
     
         36 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is selected from the group consisting of:
 (palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NH 2 ; and   (myr)-TPDINPAWYASRGIRPVGRF-NH 2 .   
     
     
         37 : A method according to  claim 21 :
 wherein the lipidated analog of prolactin-releasing peptide is administered to a human subject suffering from obesity; and   wherein the lipidated analog of prolactin-releasing peptide is administered peripherally.   
     
     
         38 : The method of  claim 21 , wherein the lipidated analog of prolactin-releasing peptide is selected from the group consisting of:
 (N-palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NHMe;   (N-palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NOMe;   (N-myr)-TPDINPAWYTGRGIRPVGRF-NH 2 ; and   (N-myr)-TPDINPAWYASRGIRPVGRF-NH 2 .   
     
     
         39 : The method of  claim 21 , wherein said lipidated analog is:
 (palm)-SRTHRHSMEIRTPDINPAWYASRGIRPVGRF-NH 2 .   
     
     
         40 : A method of lowering food intake in a subject, the method comprising administering a lipidated analog of prolactin-releasing peptide to the subject, wherein the lipidated analog of prolactin-releasing peptide is according to a formula:
   J1- k R m H n HS q EuRTPDINPAWY mo R pr RP s GR t -NH2  (III);
   wherein:   k is serine, threonine or diaminopropionic acid;   m is threonine, alanine or methylalanine;   n is glutamine or arginine;   q is methionine or norleucine;   u is threonine or isoleucine;   o is glycine or serine;   p is glycine, alanine, proline or N-methylglycine;   r is isoleucine, alanine or phenylglycine;   s is valine or phenylglycine;   t is phenylalanine or an amino acid with a side chain containing CH2-Ar or CH2-S—CH2-Ar, where Ar represents phenyl or naphtyl, optionally substituted by halogen or nitro group;   J 1  represents a fatty acid C6 to C18 bound by the amide bond to the amino group of the N-terminal amino acid; and   wherein said kRmHnHSqEuRTPDINPAWYmoRp is shortened by eliminating from 1 to 10 amino acids from its N-terminus or its C-terminus.