SECRETION KINETICS OF ALZHEIMERS AMYLOID BETA-PROTEIN DIFFERS FROM SECRETED BETA-AMYLOID PRECURSOR PROTEIN

Amyloid beta-protein (A beta) and secreted beta-amyloid precursor prot ein (sAPP), derived from beta-amyloid precursor protein (APP), are nor mally released by cultured mammalian cells. We investigated by pulse-c hase analysis the secretion kinetics of these two APP derivatives usin g mouse cholinergic SN49 cell lines stably transfected with mouse APP6 95 cDNA. After both A beta and sAPP peaked at about the second hour, s APP decreased with a half-life of approximately 5 hours, but A beta re mained almost unchanged for at least 14 hours. These results indicate that A beta is more stable than sAPP in the SN49 conditioned medium. ( C) 1995 Academic Press, Inc.