Spectrophotometric studies of the interaction of S-adenosylhomocysteinase with adenosine, adenine and cordycepin.

ABSTRACT

The spectral changes observed on interaction of S-adenosylhomocysteinase with adenine and cordycepin are approximated by the addition of dimethylsulfoxide to the aqueous solutions of these compounds, but not by protonation of the compounds. Although adenosine when bound to the enzyme undergoes partial reactions, it gives a spectral change similar to those obtained with adenine and cordycepin, except for the occurrence of a peak at 327 nm due to the reduction of the enzyme-bound NAD. From these results, it is suggested that S-adenosylhomocysteinase binds the nucleoside substrates mainly through hydrophobic interactions.