TI - A discontinuous epitope on p36 , the major substrate of src tyrosine-protein kinase , brings the phosphorylation site into the neighbourhood of a consensus sequence for Ca2+/lipid -binding proteins . AB - Previous models of p36 based on proteolytic fragments describe the tail and core as two noninteracting domains . However , the monoclonal antibody H28 recognizes a discontinuous epitope , which covers the peptide segments around Ser 25 in the tail and around Glu 65 in the core of porcine p36 . Thus , the phosphorylatable Tyr 23 is much closer to the first consensus sequence ( residues 46-62 ) of Ca2+/lipid -binding proteins than previously thought . This apposition is in line with biochemical experiments indicating an influence of core ligands on tyrosine phosphorylation and an enhanced Ca2+ requirement of the modified p36 in phospholipid binding .