Articolo in rivista, 1992, ENG, 10.1111/j.1432-1033.1992.tb17345.x
CIONI, P; ONUFFER, JJ; STRAMBINI, GB
Istituto di Biofisica CNR
The Trp phosphorescence spectrum, intensity and decay kinetics of apo-aspartate aminotransferase, pyridoxamine-5P-aspartate-aminotransferase and pyridoxal-5P-aspartate aminotransferase were measured over a temperature range 160-273 K. The fine structure of the phosphorescence spectra in low-temperature glasses, with 0-0 vibrational bands centered at 408, 415 and 417 nm, for both apoenzyme and pyridoxamine-5P-enzyme reveals a marked heterogeneity of the chromophore environments. Only for the pyridoxal-5P form of the enzyme is the triplet emission strongly quenched and, in this case, the spectrum displays a unique 0-0 vibrational band centered at 415 nm. Concomitant to quenching, there is Trp-sensitized delayed fluorescence of the Schiff base, an indication that quenching of the excited triplet state is due, at least in part, to a process of triplet singlet energy transfer to the ketoenamine tautomer.
European journal of biochemistry (Print) 209 (2), pp. 759–764
Trp phosphorescence, aspartate aminotransferase
Strambini Giovanni Battista, Cioni Patrizia
ID: 349629
Year: 1992
Type: Articolo in rivista
Creation: 2016-03-04 12:38:05.000
Last update: 2016-03-04 12:38:05.000
CNR authors
External IDs
CNR OAI-PMH: oai:it.cnr:prodotti:349629
DOI: 10.1111/j.1432-1033.1992.tb17345.x
ISI Web of Science (WOS): A1992JX22200033