Abstract
1 Vasa deferentia from guinea-pigs were exposed to 14C-SY28 HBr (5·32 × 10−6m) washed, lipid extracted, and broken up. 2 The tissue was digested with papain, hydrolyzed with 6 n HCl, and gel filtration performed. 3 Aliquots at each stage were used for paper chromatography and autoradiography. 4 Three labelled spots (in addition to unbound 2-halogenoalkylamine) were located from acid hydrolysate and a fourth from gel filtrate. 5 Selected amino-acids were complexed with 14C-SY28 and the procedure repeated. The RF values were compared with those of the same amino-acids with and without 6 n HCl. 6 Histidine, aspartic acid, arginine and serine gave a significant degree of binding of 14C-SY28. 7 The theoretical implications are discussed.