Avtor/Urednik		Čopič, Alenka
Naslov		Celična izolacija visoko-afinitetnih vezavnih proteinov za fosfolipaze A2 v prašičjem možganskem korteksu in izolacija 180 kDa receptorja
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		2000
Obseg		str. 69
Jezik		slo
Abstrakt		Phospholipases A2 (PLA2s) hydrolize fatty acyl ester linkage at the sb-2 position in a phospholipid molecule. They can be divided into high and low molecular mass PLA2s. The low-molecular mass PLA2s are a group of structurally very similar proteins, which are usually secretory. However, they are involved in a number of different psychological processes, and their function is not always directly related to their enzymatic activity. Both mammalian tissue and venoms of different snakes are rich sources of low-molecular mass PLA2s. Ammodytoxin C (AtxC) is one of the presynaptically neurotoxic PLA2s found in the venom of the long-nosed viper. It blocks the release of acetylcholine from nerve terminals. In order for AtxC to trigger its neurotoxic effect, it must bind to specific receptor proteins on the target cells. Two high-affinity AtxC-binding proteins, R180 and R25, were recently identified in porcine brain cortex. R180 binds both toxic and non-toxic PLA2s, while R25 is specific for ammodytoxins. We hope that the characterization of these receptor proteins will help us explain the moelcular mechanisms of action of neurotoxic PLA2s. On the other hand, this research should contribute to our understanding of endogenous mammalian PLA2s, which participate in cellular processes also as ligands for specific receptors. We investigated the subcellular localization of R180 and R25 in porcine brain cortex. Both receptors are integral membrane proteins but they do not reside in the same cellular compartments. While R180 is localized on the plasma membranes, R25 is an intracellular protein. Our results suggest that it resides in mitochondria, however, we cannot exclude other cellular structured of similar density. From porcine brain cortex R180 was purified to homogenicity by means of lectin- and AtxC-affinity chromatographies. (Abstract truncated at 2000 characters).
Deskriptorji		CEREBRAL CORTEX PHOSPHOLIPASES A RECEPTORS, PRESYNAPTIC MEMBRANE PROTEINS VIPER VENOMS 4-NITROPHENYLPHOSPHATASE CYTOCHROME-C OXIDASE CATHEPSINS SWINE RADIOLIGAND ASSAY NADPH-FERRIHEMOPROTEIN REDUCTASE CHROMATOGRAPHY, AFFINITY ELECTROPHORESIS, POLYACRYLAMIDE GEL