Infrared studies of interaction between metal ions and Ca2+‐binding proteins Marker bands for identifying the types of coordination of the side‐chain COO− groups to metal ions in pike parvalbumin (pI = 4.10)

FEBS Letters

Tanokura, Masaru⁴  Hiraoki, Toshifumi¹  Tasumi, Mitsuo²  Yazawa, Michio³  Tsutsumi, Akihiro¹  Nara, Masayuki² 

[1] Department of Applied Physics, Faculty of Engineering, Hokkaido University, Kita-ku, Sapporo 060, Japan;Department of Chemistry, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan;Department of Chemistry, Faculty of Science, Hokkaido University, Kita-ku, Sapporo 060, Japan;Biotechnology Research Center, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan

关键词: Pike parvalbumin;    Ca2+-binding protein;    Metal-ligand interaction;    Infrared spectroscopy;    COO− antisymmetric stretch;    Coordination type;   

DOI  :  10.1016/0014-5793(94)00645-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Metal-ligand interactions in the Ca²⁺-binding sites of pike parvalbumin (pI = 4.10) have been examined by Fourier-transform infrared spectroscopy. The region of the COO⁻ antisymmetric stretch provides useful information on the types of coordination of the COO⁻ groups to the metal ions in the Mg²⁺-, Mn²⁺-, and Ca²⁺-bound forms. In the spectrum of the Ca²⁺-bound form, two bands are observed at 1,582 and 1,553 cm⁻, whereas, in the spectra of the Mg²⁺- and Mn²⁺-bound forms, bands are observed only in the region around 1,582 cm⁻¹ and no band is found in the region around 1,553 cm⁻¹. The 1,553-cm⁻¹ band of the Ca²⁺-bound form reflects the bidentate coordination of the COO⁻ groups of both Glu-62 in the CD site and Glu-101 in the EF site to the Ca²⁺ ions, which has been made clear by X-ray analysis as a feature of the Ca²⁺-bound form. Absence of such a band in the spectrum of the Mn²⁺-bound form is consistent with the X-ray structure of this form where both of the two COO⁻ groups are unidentate. These unidentate COO⁻ groups of Glu-62 and Glu-101 in the Mn²⁺-bound form seem to give rise to a band at 1,577-1,574 cm⁻. The spectrum of the Mg²⁺-bound form is also consistent with the ‘pseudo-bridging’ coordination of the COO⁻ group of Glu-101 reported in the X-ray structure of a form where the Mg²⁺ ion occupies only the EF site, and the same spectrum is further indicative of the ‘pseudo-bridging’ coordination of the COO⁻ group of Glu-62.

【 授权许可】

Unknown