An isolated epitope comprising the formula Wherein: G is Glycine E is Glutamate D is Aspartate Y is Tyrosine S is sulfate or a sulfated molecule X is any amino acid except the above z is 0, 1, or 2 t is 1, 2 or 3 r is 0 or 1 u is 0 to 2 n is 0 to 3 m is 0 to 3 wherein at least one Y is sulfated; wherein if n=0 then m>0; wherein if m=0 then n>0; and further wherein the isolated epitope is capable o