Fluorescence spectroscopic studies on interactions between liver annexin VI and nucleotides--a possible role for a tryptophan residue.

摘要: Annexin VI is a 68-kDa calcium-, phospholipid-, and cytoskeletal-element-binding protein, which has been implicated in various processes, including calcium release sequestration calcifying cartilage, receptor-mediated endocytosis human fibroblasts, secretion from chromaffin granules. In these processes it was found that, addition to Ca2+ annexin, the presence of ATP also prerequisite. present report we show that annexin binds binding nucleotide protein accompanied by quenching an intrinsic fluorescence VI, be specific for 2'-(or 3')-O-(2,4,6-trinitrophenyl)adenosine 5'-triphosphate, GTP ATP, dependent on conformation. The nucleotide-binding site within molecule likely close tryptophan-containing domain VI. We propose plays role physiological ligand its may represent alternative cellular mechanism regulation annexin-membrane interactions coupled overall energy transitions cell.