The interaction of a naphthalene dye with 2 -macroglobulin, free or bound to trypsin.

摘要: Abstract Porcine α 2 - macroglobulin can bind 1-anilino-8-naphthalene sulfonate (ANS). At pH 7.3 and 25 °C, the apparent association constant number of binding sites have been determined. The fluorescence quantum yield conjugate is 30-fold higher than that ANS in water, while maximal emission band shifted from green to blue by 55 nm. Trypsin does not at but stable complex formed between 1 mole moles trypsin with a greater enhancement intensity stronger does. These data are consistent local conformational change molecule complex; aromatic amino acids being unburied more rigid environment could be responsible for different behaviour. increase observed may also due exclusion some water molecules near site. Amidasic activity perturbed binding, proving there no competition active site enzyme. Only small part photon energy absorbed protein transferred ANS.