Isolation and characterization of a neu protein-specific activating factor from human ATL-2 cell conditioned medium.
The rat neu gene product is a 185 kD membrane bound tyrosine kinase that is closely related to, yet distinct from the epidermal growth factor receptor. The biochemical and cellular effects of a neu protein-specific activating factor (NAF) detected in human ATL-2 cell conditioned medium were recently described (1). To further characterize NAF, some of its physicochemical properties were examined and a method for purifying this factor from ATL-2 cell conditioned medium was developed. In these studies NAF was found to be heat stable and sensitive to the protease chymotrypsin. In addition, a method for purifying this activity was developed using a quantifiable, in vitro autophosphorylation assay system to measure NAF activity in fractions following ion-exchange and then reverse-phase HPLC.
Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104-6082.
J G
JG
Davis
J
J
Hamuro
C Y
CY
Shim
A
A
Samanta
M I
MI
Greene
K
K
Dobashi
D002460:Cell Line; D003470:Culture Media; D004789:Enzyme Activation; D006801:Humans; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011519:Proto-Oncogenes; D018719:Erb-b2 Receptor Tyrosine Kinases
D003470:Culture Media; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases