title: Spectral studies on the calcium-binding properties of Mts1 protein and its interaction with target protein.
abstract: Two calcium-binding sites of the Mts1 protein, a member of S-100 protein family, were distinguished with the Fluo-3 fluorescent technique. The geometric mean of the apparent dissociation constant (Kd) for these two sites is 2.6 microM; the Hill coefficient (nH) is 0.98. In the presence of a novel target protein p37, isolated from the mouse adenocarcinoma cell line CSML-100, Mts1 binds Ca2+ ions with higher affinity and with strong positive cooperativity (Kd = 0.2 microM, nH = 1.91). Interaction of Mts1 with p37 is confirmed by the fluorescent probe 2-p-toluidinylnaphthalene-6-sulfonate (TNS). Reaction with TNS shows that p37 interacts with the hydrophobic site of Mts1 which is exposed due to the binding of Ca2+ ions.
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Science, Moscow, Russian Federation. buh@genom-ii.eimb.rssi.ru
authors.forename: E A
authors.initials: EA
authors.lastname: Dukhanina
authors.forename: A S
authors.initials: AS
authors.lastname: Dukhanin
authors.forename: M Y
authors.initials: MY
authors.lastname: Lomonosov
authors.forename: E M
authors.initials: EM
authors.lastname: Lukanidin
authors.forename: G P
authors.initials: GP
authors.lastname: Georgiev
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D051379:Mice; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; D013053:Spectrophotometry; D014407:Tumor Cells, Cultured
chemical_list: D002135:Calcium-Binding Proteins; D011506:Proteins; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C470944:S100a4 protein, mouse; D002118:Calcium