Labile zinc-assisted biological phosphate chemosensing and related molecular logic gating interpretations.
Herein, molecular fluorescence 'OFF-ON' behavior with aqueous addition of biological phosphate and Zn(2+) is studied with Zn(2)(slys)(2)Cl(2) [H(2)slys = 6-amino-2-{(2-hydroxybenzylidene)amino}hexanoic acid], a fluorescent water-soluble complex, using various spectroscopic tools (e.g., (31)P NMR, UV-vis, emission, and CD spectroscopy) at the micromolar level. Adduct-dependent fluorescence intensity changes can be interpreted as a two-input (cation/anion) implication molecular logic gating system. A displacement study of PPi from the dizinc complex is also reported. Diphosphate and triphosphate addition/displacements were also studied. (31)P NMR spectroscopy shows gradual NMR peak shifts from bound ADP/GDP to free ADP/GDP with increasing [PPi]. In the emission spectrum, fluorescence quenching is shown: CD signal maxima decrease with addition of PPi. These displacement events are also tested with triphosphates (ATP, GTP), and their binding strength/displacement ability over ADP/GDP is quantified: PPi > ATP ≈ GTP (3.35 ± 0.77 × 10(4) M(-1) for PPi, 7.73 ± 1.79 × 10(3) M(-1) for ATP, 9.21 ± 2.88 × 10(3) M(-1) for GTP over 1·ADP). Many anions and cations were also screened for selectivity. Tubulin polymerization was assayed in the presence of 1 and its copper analogue which reflected a slight inhibition in polymerization.
Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
Kibong
K
Kim
Yonghwang
Y
Ha
Léo
L
Kaufman
David G
DG
Churchill
D000244:Adenosine Diphosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D002942:Circular Dichroism; D005453:Fluorescence; D006153:Guanosine Diphosphate / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015336:Molecular Probe Techniques; D010710:Phosphates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism; D015032:Zinc / Q000032:analysis / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry
D010710:Phosphates; D014404:Tubulin; D017967:Zinc Compounds; D006153:Guanosine Diphosphate; C043952:zinc phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D015032:Zinc