Structural changes of human RNase L upon homodimerization investigated by Raman spectroscopy

0383359 - ÚOCHB 2013 RIV NL eng J - Článek v odborném periodiku
Kříž, M. - Snášel, Jan - Kopecký, V. Jr. - Páv, Ondřej - Rosenberg, Ivan - Štepánek, J.
Structural changes of human RNase L upon homodimerization investigated by Raman spectroscopy.
Biochimica Et Biophysica Acta-Proteins and Proteomics. Roč. 1824, č. 9 (2012), s. 1039-1044. ISSN 1570-9639. E-ISSN 1878-1454
Grant CEP: GA ČR GA202/09/0193; GA AV ČR KAN200520801
Grant ostatní: GA AV ČR(CZ) KJB101120805
Program: KJ
Institucionální podpora: RVO:61388963
Klíčová slova: RNase L * Raman spectroscopy * DCDR spectroscopy * phosphonate oligoadenylate * ligand binding
Kód oboru RIV: BO - Biofyzika
Impakt faktor: 3.733, rok: 2012

RNase La key enzyme in the host defense system, is activated by the binding of 2'-5'-linked oligoadenylates (2-5A) to the N-terminal ankyrin repeat domain, which causes the inactive monomer to form a catalytically active homodimer. We focused on the structural changes of human RNase L as a result of interactions with four different activators: natural 2-5 pA(4) and three tetramers with 3'-end AMP units replaced with ribo-, arabino- and xylo-configured phosphonate analogs of AMP (pA(3)X). The extent of the RNase L dimerization and its cleavage activity upon binding of all these activators were similar. A drop-coating deposition Raman (DCDR) spectroscopy possessed uniform spectral changes upon binding of all of the tetramers, which verified the same binding mechanism. The estimated secondary structural composition of monomeric RNase L is 44% alpha-helix, 28% beta-sheet, 17% beta-turns and 11% of unordered structures, whereas dimerization causes a slight decrease in alpha-helix and increase in beta-sheet (ca. 2%) content. The dimerization affects at least three Tyr, five Phe and two Trp residues. The alpha-beta structural switch may fix domain positions in the hinge region (residues ca. 336-363) during homodimer formation.
Trvalý link: http://hdl.handle.net/11104/0213318