RFamide-Related Peptides and Methods Thereof

Abstract

Provided herein methods and compositions directed to RFRP-1 polypeptides for modulating cardiac contractile function, for preventing and/or treating cardiac disorders.

1 . An isolated peptide comprising the amino acid sequence:
 X1-X2-X3-X4-X5-X6-X7-X8-X9-X10-X11-F (SEQ ID NO: 13) wherein,   any one of amino acids X1 to X8 is present or absent, X9 and X11 are present, X10 is L or Q, and said peptide modulates cardiac function in a vertebrate; or a salt, amide or ester thereof.   
     
     
         2 . An isolated peptide comprising the amino acid sequence:
 X1-X2-X3-X4-X5-X6-X7-X8-X9-X10-X11-F (SEQ ID NO: 13) wherein,   any one of amino acids X1 to X8 is present or absent, X9 and X11 are present, X10 is L or Q;   with the provisos that:   when said peptide consists of a pentapeptide, the amino acid sequence of said pentapeptide is not LPLRF (SEQ ID NO: 3); and when   said peptide consists of a dodecapeptide and X6, X7, X8, X9, X10, and X11 are each A, N, L, P, L, and R respectively, X4 is not S or P.   
     
     
         3 . The peptide of  claim 2  wherein said peptide modulates cardiac function in a vertebrate. 
     
     
         4 . The peptide of  claim 1  wherein X1 is an amino acid other than M, V, or S;
 X5 is other than F, or V; X7 is other than N; X9 is other than P, and X11 is other than R; and wherein each of X1, X5, X7, X9, and X11 is independently selected from one another. 
 
     
     
         5 . The peptide of  claim 1  wherein X11 is an amino acid other than R. 
     
     
         6 . The peptide of  claim 4  wherein at least one of X1, X5, X7, X9, and X11 is A. 
     
     
         7 . The peptide of  claim 1 , wherein X8 is present. 
     
     
         8 . The peptide of  claim 7 , wherein X8 is A, V or L; and X9 is P or F. 
     
     
         9 . The peptide according to  claim 1  wherein X2 is P, X4 is S; X6, X7, X8 and X9 are each respectively A, N, L, and P. 
     
     
         10 . The peptide of  claim 1 , wherein at least one of X3 and X7 is an amino acid other than histidine. 
     
     
         11 . The peptide of  claim 10  wherein X1 and X2 are absent. 
     
     
         12 . The peptide of  claim 10  wherein X7 is A. 
     
     
         13 . (canceled) 
     
     
         14 . The peptide of  claim 1 , wherein X3 is Bpa. 
     
     
         15 .- 20 . (canceled) 
     
     
         21 . A pharmaceutical composition comprising a pharmaceutically acceptable carrier and an isolated peptide according to any one of  claims 1 - 19  and  34 . 
     
     
         22 .- 24 . (canceled) 
     
     
         25 . A method of treating a cardiac disorder in a vertebrate, including a mammal, said method comprising administering to said vertebrate a therapeutically effective amount of the peptide of any one of  claims 1 - 19  and  34 . 
     
     
         26 . A method of screening for an agent that modulates cardiac function in a vertebrate, said method comprising:
 a) contacting a first group of one or more myocytes with an isolated peptide comprising a sequence selected from the group consisting of:   MPHSFANLPLRF (SEQ ID NO: 2); MPPSFANLPLRF (SEQ ID NO: 14); VPNSVANLPLRF (SEQ ID NO: 15); VPHSAANLPLRF (SEQ ID NO: 16);   MPPSAANLPLRF (SEQ ID NO: 17); SLKPAANLPLRF (SEQ ID NO: 18), LPLRF (SEQ ID NO: 3), PLRF, PQRF, FLRF, FQRF, APLRF (SEQ ID NO: 19), APQRF (SEQ ID NO: 20), AFLRF (SEQ ID NO: 21), AFQRF (SEQ ID NO: 22), VPLRF (SEQ ID NO: 23), VPQRF (SEQ ID NO: 24), VFLRF (SEQ ID NO: 25), and VFQRF (SEQ ID NO: 26), wherein F is amidated;   b) contacting the first group set forth in a), or a second group of one or more myocytes with a test agent; and measuring the effect subsequent to the contacting with the test agent; and   determining from the comparison of the measurement in step a) to that of step b) whether the test.   
     
     
         27 .- 31 . (canceled) 
     
     
         32 . A method of modulating PKC-mediated signal transduction in a cell or tissue of a vertebrate including a mammal, comprising contacting said cell or tissue with an isolated peptide comprising the amino acid sequence X1-X2-X3-X4-X5-X6-X7-X8-X9-X10-X11-F (SEQ ID NO: 13) wherein,
 any one of amino acids X1 to X8 is present or absent, X9 and X11 are present, and X10 is L or Q; or a salt, amide or ester thereof.   
     
     
         33 .- 34 . (canceled)