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A long lifetime component in the tryptophan fluorescence of some proteins
- Source :
- European biophysics journal : EBJ. 23(6)
- Publication Year :
- 1995
-
Abstract
- The tryptophan fluorescence of two membrane proteins (outer membrane protein A and lactose permease), a 21-residue hydrophobic peptide, three soluble proteins (rat serum albumin, ribonuclease T1, and azurin), and N-acetyltryptophanamide (NATA) was investigated by time-resolved measurements extended over 65 ns. A long lifetime component with a characteristic time of 25 ns and an amplitude below 1% was found for outer membrane protein A, lactose permease, the peptide in lipid membranes, and azurin in water, but not for rat serum albumin, ribonuclease T1, and NATA in water. When outer membrane protein A was dissolved and unfolded in guanidinum hydrochloride, the long lifetime component disappeared. Hence, a hydrophobic environment seems to be a necessary requirement for the long lifetime component to be present. However, NATA dissolved in butanol does not exhibit the long lifetime component, while the peptide dissolved in the same solvent under conditions which preserve its helical structure does show the long lifetime. Thus, a regular secondary structure for the polypeptide chain to which the tryptophan residue belongs seems to be a second necessary requirement for the long lifetime component to be present. The long lifetime component may therefore be seen in the context of protein substates.
- Subjects :
- Lactose permease
Time Factors
Monosaccharide Transport Proteins
Protein Conformation
Molecular Sequence Data
Biophysics
Context (language use)
Peptide
Biophysical Phenomena
Fluorescence
Azurin
Animals
Amino Acid Sequence
Ribonuclease T1
Protein secondary structure
Serum Albumin
chemistry.chemical_classification
Symporters
Chemistry
Escherichia coli Proteins
Tryptophan
Membrane Transport Proteins
Proteins
General Medicine
Rats
Crystallography
Membrane
Spectrometry, Fluorescence
Membrane protein
Peptides
Bacterial Outer Membrane Proteins
Subjects
Details
- ISSN :
- 01757571
- Volume :
- 23
- Issue :
- 6
- Database :
- OpenAIRE
- Journal :
- European biophysics journal : EBJ
- Accession number :
- edsair.doi.dedup.....1a165ca3edbc4f0a45ebe838d7a26ac3