Fluorescence studies of nucleotide interactions with bovine adrenal chromogranin A.
The binding of the fluorescent probe bis-ANS to chromogranin A, the major protein of adrenal chromaffin vesicles, caused a marked enhancement and blue shift in the fluorescence emission spectrum. The emission maximum shifted from 515 nm to 480 nm and the yield increased approx. 75-fold upon addition of 10 microM chromogranin A to 1 microM bis-ANS. Adenine nucleotides had clear effects on the bis-ANS fluorescence signal, while other nucleotides such as GTP, UTP and CTP had no discernible effect. Specifically, ATP caused a decrease in the fluorescence, whereas ADP and AMP caused a fluorescence increase. These results indicate adenine nucleotide binding to chromogranin A. Substitution of ATP with epsilon-ATP, an ATP derivative with a modification on the six-membered ring of the adenine base, failed to reduce the fluorescence intensity. Therefore, it was concluded that adenine bases play an important role in the chromogranin A-adenine nucleotide interaction.
Yoo
S H
SH
Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235.
Albanesi
J P
JP
Jameson
D M
DM
D000255:Adenosine Triphosphate / Q000378:metabolism; D000313:Adrenal Medulla / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002837:Chromaffin Granules / Q000378:metabolism; D053379:Chromogranin A; D002864:Chromogranins / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D012265:Ribonucleotides / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods
D053379:Chromogranin A; D002864:Chromogranins; D009419:Nerve Tissue Proteins; D012265:Ribonucleotides; D000255:Adenosine Triphosphate