This product is an amphiphilic fluorescent probe for protein studies . Excitation of the unbound dye at 380 nm results in a low fluorescent emission with a maximum at 545 nm. The fluorescence intensity of ANS increases when the dye binds to the hydrophobic regions of a protein . The protein-ANS complex has an emission spectrum which is shifted to a broad maximum at 470 nm. At pH 8, protein causes a 40-fold increase in the relative quantum yield compared to free ANS in solution . ANS has been used to monitor protein conformational changes by binding to the hydrophobic regions of a protein , to gain new insight into protein binding interactions, often by acting as reporter or competitor ligands, to investigate the visual excitation process and structural aspects of photoreceptor cell membranes , and to probe (and disrupt) the structure of both high- and low-density lipoproteins. It has also been used as a substrate in a chemiluminescent enzyme immunoassay system and as a dye for yeast viability determination. The conformational states for apo- and holo- yeast alcohol dehydrogenase were reported under conditions of low pH using ANS fluorescence . ANS is also commonly used as a fluorescence probe to investigate molecular assemblies of surfactants and amphiphilic polymers because a blue shift of its emission maximum indicates the probe is located in less polar environment
ANS forms an inclusion complex with cyclodextrin. Such model systems are useful to mimic biological recognition and can be studied by measuring the change in fluorescence of free-ANS to complexed-ANS. When ANS enters the hydrophobic core of cyclodestrin, it′s fluorescence increases . Utilized in the reagent phase of a sodium-selective fiber-optic sensor. The reagent phase also contains a copper(II) polyelectrolyte, which binds to ANSA in the absence of sodium and quenches the fluorescence. In the presence of sodium, ANSA forms a cationic complex creating ion-pairs, causing it to fluoresce . ANS is often incorporated into di-block polymers and can be released by changes in the local environment (i.e., temperature, pH, etc.) . ANS is commonly used as a fluorescence probe to investigate molecular assemblies of surfactants and amphiphilic polymers because a blue shift of the emission maximum indicates the fluorophore is located in less polar media . Fluorescent probe for protein studies using methodologies such as steady-state and dynamic fluorescence measurements .