Jf. Hare et A. Holocher, SOLUBILITY IN NONIONIC DETERGENTS DISTINGUISHES BETWEEN SLOWLY AND RAPIDLY DEGRADED PLASMA-MEMBRANE PROTEIN, The Journal of biological chemistry, 269(8), 1994, pp. 5981-5988
Four cell surface-exposed, integral membrane proteins from H4-II-E-3 h
epatoma monolayer cultures, derivatized by the membrane-impermeant rea
gent sulfosuccinimidyl 2-(biotin-amido)ethyl-1,3-dithioproprionate, we
re resistant to extraction with Triton X-100 at 0 degrees C. Thirty-th
ree other similarly derivatized proteins were solubilized under these
same conditions. Antisera were prepared that reacted only with Triton
X-100-insoluble proteins. All four Triton X-100-insoluble proteins pre
cipitated with the antibody were slowly degraded (t(1/2) > 100 h). By
contrast, all but four Triton X-100-soluble proteins were rapidly degr
aded (t(1/2) = 24 h). The detergent-insoluble proteins did not possess
glycosylphosphatidylinositol anchors nor were they solubilized by Tri
ton X-100 after disruption of the cytoskeleton. In addition, they were
insoluble in Triton X-100 in isolated membrane preparations but solub
le when isolated on streptavidin-agarose and removed from other membra
ne proteins. We conclude that protein-protein interactions within the
membrane itself result in insolubility in non-ionic detergents for a s
mall cohort of plasma membrane proteins and that this may be directly
related to the increased metabolic stability for this class of protein
s.