title: Solid-State Nuclear Magnetic Resonance Analysis Reveals a Possible Calcium Binding Site of Pradimicin A.
abstract: Pradimicin A (PRM-A) is a unique natural product that recognizes d-mannopyranoside (Man) in the presence of Ca2+ion. Although the Man binding geometry of PRM-A is largely understood, the molecular basis of Man recognition has yet to be established because of the lack of information regarding Ca2+binding geometry. In this work, to examine the Ca2+binding site of PRM-A, we performed a solid-state nuclear magnetic resonance experiment using111Cd2+as a surrogate probe for Ca2+. Evaluation of13C-111Cd distances in the [PRM-A/111Cd2+] complexes by rotational-echo double resonance (REDOR) and111Cd frequency selective REDOR (FSR) revealed that PRM-A binds111Cd2+at the anthraquinone moiety, which contradicts the previous hypothesis of the alanine moiety being the Ca2+and Cd2+binding sites of PRM-A. The distances between Cd2+and the carbon atoms at the binding site of PRM-A were found to be 3.5 ± 0.2 Å. Importantly, Man binding was shown not to alter the distances, indicating that [PRM-A/Ca2+] and [PRM-A/Ca2+/Man] complexes have similar Ca2+binding geometries. This study provides an important clue to understanding the molecular basis of Man recognition of PRM-A.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Nakagawa
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takegoshi
mesh_terms: D018943:Anthracyclines / Q000737:chemistry*; D001665:Binding Sites; D002104:Cadmium / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008358:Mannose / Q000737:chemistry*; D018716:Molecular Mimicry; D015394:Molecular Structure; D000095643:Pradimicins and Benanomicins
chemical_list: D018943:Anthracyclines; D002104:Cadmium; D002118:Calcium; D007554:Isotopes; D008358:Mannose; C058036:pradimicin A; D000095643:Pradimicins and Benanomicins