Human fetoacinar pancreatic protein : an oncofetal glycoform of the normally secreted pancreatic bile-salt-dependent lipase

摘要: A fetoacinar pancreatic protein (FAP) associated with the ontogenesis, differentiation and oncogenic transformation of human exocrine pancreas has been purified from juices patients suffering pancreatitis or duodenal cancers invading [Escribano Imperial (1989) J. Biol. Chem. 264, 21865-21871]. This striking similarities, i.e. M(r), amino acid composition N-terminal sequence, to bile-salt-dependent lipase (BSDL) normal secretion. The aim this study was gain further insight into nature two proteins. Reactivity mouse monoclonal antibody J28 (mAb J28), which characterizes FAP, enzyme activity could not be dissociated during biochemical purification BSDL. Furthermore, a polyclonal antiserum raised against BSDL reacted completely FAP in Western-blot analysis giving additional support idea similar molecular structures for FAP. However, by same technique, mAb relatively restricted population molecules. classical preparation separated molecules bearing epitope those devoid it immunoaffinity on immobilized J28. subpopulations had identical sequences some differences their compositions. they different carbohydrate J28-epitope-bearing were active substrates, although specific decreased. These results are consistent existence closely related polypeptide chains glycan counterparts. Therefore, if name is reserved epitope, linked carbohydrate-dependent structure. represent an oncofetal-related variant Our result first demonstration oncofetal-type subpopulation otherwise normally secreted enzyme.