Properties of kinesin isolated from human prostatic DU 145 tumor cells and bovine brain

We have isolated and compared the 116-kilodalton (kDa) kinesin heavy chain from DU 145 human prostatic tumor cells and bovine brain. Comparative sodium dodecyl sulfate - polyacrylamide gel electrophoreses (SDS-PAGE), Western blots, and proteolytic digestion analysis all showed that the 116-kDa polypeptides from both sources were indistinguishable. Polyclonal antibodies raised against sea urchin kinesin cross-reacted with both brain and DU 145 kinesin on Western blots. SDS-PAGE and A-5m chromatographic studies indicated that kinesin forms a quarternary heteropolymer of approximately 400 kDa. DU 145 cells had three proteins of 116, 72, and 64 kDa forming the heteropolymer, in a 2:1:1 ratio, whereas brain cells appeared to have equimolar amounts of the 116-kDa heavy chain and a 64-kDa light chain.