Spectra of glutamate dehydrogenase with diethylstilbestrol.

Glutamate dehydrogenase displays hyperchromicity at 256 nm and at 276 nm upon binding of diethylstilbestrol. Increase in absorbancy is linear at both regions up to 250 micrometer DES, and becomes parabolic at higher concentration of DES. ADP in the presence of DES causes decrease in absorbancy at 256 nm; absorbancy at 276 nm increased by DES is not affected by ADP. DES prevents spectral effects produced by GTP (decrease in absorbancy at 254 nm and at 276 nm). ADP still decreases absorbancy at 254 nm, leaving the 276 nm region unchanged. ADP enhances spectral effects produced by GTP. GTP, however, prevents changes produced by ADP.