New component in protein fluorescence

Conference · Tue Jan 01 04:00:00 EST 1980

OSTI ID:5163567

Longworth, J W

Tryptophyl residues in proteins absorb at longer wavelengths than tyrosyl residues and thus the tryptophyl fluorescence can be selectively excited. In addition, tryptophyl residues have a fluorescence maximum at much longer wavelengths than tyrosyl residues and are the predominant source of fluorescence at the long wavelength region. The contribution of tyrosyl fluorescence to protein fluorescence can be determined by exploiting these spectral properties. The tyrosyl fluorescence of native human serum albumin is different than the fluorescence of N-acetyl-L-tyrosinamide. The spectral maximum is at longer wavelength and the spectral width is greater. This is caused by a second component with a maximum at 345 nm. The excitation spectrum of the 345 nm component is similar to the excitation spectrum of the normal 304 nm tyrosyl component. The 345 nm is largely absent from denatured serum albumin. An excited singlet state protolysis from the buried tyrosyl residues explains the appearance of the 345 nm component. A possible acceptor base is an amino group of buried lysyl residue.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5163567
• Report Number(s): CONF-8006122-1
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
AMINO ACIDS
ANIMALS
AZOLES
BLOOD SERUM
CARBOXYLIC ACIDS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUORESCENCE
FREQUENCY DEPENDENCE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INDOLES
LUMINESCENCE
MAMMALS
MAN
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PRIMATES
PROTEINS
PYRROLES
SPECTRA
TRYPTOPHAN
VERTEBRATES