Chip-based sensing of membrane release of unprocessed cell surface proteins in vitro and in serum and its (patho)physiological relevance.

Chip-based sensing of membrane release of unprocessed cell surface proteins in vitro and in serum and its (patho)physiological relevance. Am J Physiol Endocrinol Metab. 2019 Apr 30;: Authors: Müller GA, Herling AW, Stemmer K, Lechner A, Tschöp MH Abstract To study the possibility that components of eukaryotic plasma membranes are released under certain (patho)physiological conditions, a chip-based sensor was developed for detection of cell surface proteins, which are anchored at the outer leaflet of eukaryotic plasma membranes by a covalently attached glycolipid, exclusively, and might be prone to spontaneous or regulated release on basis of their amphiphilic character. For this, unprocessed full-length glycosylphosphatidylinositol-anchored proteins (GPI-AP) with associated phospholipids were specifically captured and detected by a chip- and microfluidic channel-based sensor leading to changes in phase and amplitude of surface acoustic waves (SAW) propagating over the chip surface. Unprocessed GPI-AP in complex with lipids were found to be released from rat adipocyte plasma membranes immobilized on the chip which was dependent on the flow rate and composition of the buffer stream. The complexes were identified in the incubation medium of rat adipocytes, in correlation to the cell size, and in rat and human serum. With rats, the measured changes in SAW phase shift, reflecting specific mass/size or amount of the unprocessed GPI-AP in...
Source: American Journal of Physiology. Endocrinology and Metabolism - Category: Physiology Authors: Tags: Am J Physiol Endocrinol Metab Source Type: research