Identification and subcellular localization of a 21-kilodalton molecule using affinity-purified antibodies against alpha-transforming growth factor.
Monospecific antibodies were generated against each of six different peptide sequences derived from rat and human alpha-transforming growth factor (alpha-TGF). The affinity-purified antibody to the 17 amino acid carboxyl-terminal portion of the molecule proved most useful in detecting alpha-TGF. When used in a peptide-based radioimmunoassay, it was possible to measure nanogram quantities of native alpha-TGF in conditioned cell culture media. When used to analyze cell lysate, these antibodies specifically recognized a 21-kilodalton protein species. Indirect immunofluorescence localization procedures revealed a high concentration of alpha-TGF in a perinuclear ring with a diffuse cytoplasmic distribution. These results suggest that a precursor form of alpha-TGF has a cellular role beyond that of an autocrine growth factor.
Hazarika
P
P
Pardue
R L
RL
Earls
R
R
Dedman
J R
JR
D000818:Animals; D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D000936:Antigen-Antibody Complex; D002460:Cell Line; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D005455:Fluorescent Antibody Technique; D006133:Growth Substances / Q000032:analysis*; D006801:Humans; D008545:Melanoma; D010455:Peptides / Q000032:analysis*; D011863:Radioimmunoassay; D051381:Rats; D013347:Subcellular Fractions / Q000032:analysis; D015291:Transforming Growth Factors
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D006133:Growth Substances; D010455:Peptides; D015291:Transforming Growth Factors