title: The nature of the phosphorus linkage in component I, a phosphoprotein isolated from the blood serum of DES-treated cockerels.
abstract: The  nature of the phosphorus linkage in electrophoretic component I of the blood serum of DES-treated cockerels was investigated by enzymatic and partial acid and alkali dephosphorylation. The C-P bond was excluded because this bond is stable to 6 N HCl at 110 degrees C. for 20 hours, and all  the phosphorus was released under these conditions. No phosphorus was released when diesterase, pyrophosphatase and 0.25 N HCl were employed, and this excludes the diester, pyrophosphate and N-P bonds. The presence of the O-P bond was supported by the release of phosphate by the phosphatases and 0.25 N NaOH. The hydrolysate produced upon hydrolysis with pronase and papain contained phosphoserine. No phosphothreonine was present.
mesh_terms: D000818:Animals; D002645:Chickens / Q000097:blood*; D004054:Diethylstilbestrol / Q000494:pharmacology*; D006868:Hydrolysis; D008297:Male; D010750:Phosphoproteins / Q000097:blood*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*
chemical_list: D010750:Phosphoproteins; D010758:Phosphorus; D004054:Diethylstilbestrol; D010744:Phosphoric Monoester Hydrolases