Pulse-chase analyses of wild-type and Tenri-type factor XIIs in stably-transfected BHK cells. (A) Stably-transfected BHK cells were pulse-labeled for 30 minutes with 100 μCi/mL EXPRE³⁵S³⁵S and chased for 0, 1, 2, 4, 6, and 8 hours. Labeled factor XIIs from cell extracts and from culture media were immunoprecipitated and analyzed on 8% SDS-polyacrylamide gel electrophoresis. (B) In kinetic analyses, the amount of radioactivity in the pulse-labeled cell extracts was taken as 100%, and relative radioactivities of intracellular and secreted fractions are shown by ○ and •, respectively. The sum of the radioactivities of both fractions at each time is shown by □. (C) BHK cells expressing Tenri-type factor XII were pulse-labeled for 30 minutes with 100 μCi/mL EXPRE³⁵S³⁵S (lane 1) and chased in DMEM for 8 hours in the absence (lane 2) or presence (lane 3) of excess amounts of cystine. Factor XII was immunoprecipitated from the pulse-labeled cell extracts (lane 1) and chased media (lanes 2 and 3), and then electrophoresed on an 8% SDS-polyacrylamide gel.