Application of ANS fluorescent probes to identify hydrophobic sites on the surface of DREAM

Modulation of the Voltage-gated Potassium Channel (Kv4.3) and the Auxiliary Protein (KChIP3) Interactions by the Current Activator NS5806

“…The most prominent NS5806⅐KChIP3-(65-256) interactions are hydrophobic, between the nonpolar brominated phenyl ring on NS5806 and Phe-218, Tyr-174, and Ile-194 on KChIP3, whereas the more electrophilic fluorinated phenyl ring faces the solvent. We previously used a similar approach to identify the docking site of 1,8-ANS to KChIP3-(65-256) and KChIP3-(161-256) and found that the same hydrophobic cavity at the C terminus was the most favorable binding site (33). The fact that docking simulations identify the same docking site for 1,8-ANS and NS5806 correlate well with the 1,8-ANS displacement studies shown above.…”

Molecular insight of DREAM and presenilin 1 C‐terminal fragment interactions

“…Since alternative oligomerization states of DREAM directly mediate the interactions with intracellular proteins and DNA and this process depends on Ca 2+ /Mg 2+ occupancy at EF‐hands , the oligomeric states of DREAM in complex with HL9 were characterized. The anisotropy decay traces for HL9 (circles) and Ca 2+ DREAM:HL9 complex (squares) are shown in Fig A.…”

“…Since alternative oligomerization states of DREAM directly mediate the interactions with intracellular proteins and DNA and this process depends on Ca 2+ /Mg 2+ occupancy at EF-hands [2,3,6,29], the oligomeric states of DREAM in complex with HL9 were characterized. The anisotropy decay traces for HL9 (circles) and Ca 2+ DREAM:HL9 complex (squares) are shown in Fig 4A. The data were fit into a two rotational correlation-time model where the fast rotational correlation time (h 2 ) corresponds to the local rotation of FITC and the slow rotational correlation time (h 1 ) reflects global rotation of HL9 or DREAM bound HL9 ( Table 2).…”

Ca2+ and Mg2+ modulate conformational dynamics and stability of downstream regulatory element antagonist modulator

“…25 However, the detailed molecular mechanism of how Ca 21 association to the C-terminal domain EF-hands modulates the conformation of the DREAM monomer and the impact of Ca 21 /Mg 21 association on DREAM affinity for intracellular partners remains elusive. Tryptophan emission has been widely used as a sensitive probe of structural transitions in proteins including protein folding, Ca 21 /Mg 21 association to proteins and protein-protein interactions.…”