Molar extinction coefficient of a protein at 280 nm.

Marc DIEU madi at
Thu Mar 16 07:59:10 EST 1995

Is it possible to determine the molar extinction coefficient at 280 nm
of a given protein (epsilon 280 nm prot.) simply by additionning the
individual molar extinction coefficients of the different aromatic
residues which compose the sequence of the protein ? Is it correct or
not ? Is there any literature available about it ? Is the absorbance of
a residue influenced by its environment or by its position in the
three-dimentional structure of the protein ? The non-aromatic residues,
do they also contribute to some extent to the absorbance of the protein
at 280 nm ? What is the value of the molar extinction coefficient at
280 nm of Trp, Tyr, Phe and His ? 

Dominique DELFORGE,
Laboratory of Cellular Biochemistry,
FacultŽs Universitaires ND de la Paix,
61, rue de Bruxelles,
B-5000 Namur (Belgium).
Fax: ++/32/81/72.41.35.
Email: dodel at

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