title: Femtosecond dynamics of proteoheparan sulfate (HS-PG) after UV excitation--a readout for arteriosclerotic nanoplaque formation?
abstract: Ultrashort UV laser pulses were used to excite tryptophan residues of heparan sulfate proteoglycan (HS-PG) in blood substitute Krebs solution. Tryptophan fluorescence is sensitive to the environment, so its shift and decay indicate the conformation and solvation state of the protein. We monitored stimulated emission and excited-state absorption by probing with delayed white-light femtosecond pulses. Comparison with bare tryptophan revealed transient absorption features which are characteristic for HS-PG. Furthermore, the effect of adding calcium salt was investigated. Differences in the spectra from solutions with and without calcium developed during several minutes, which points to changes in protein conformation, but could only be measured in the sub-ps regime. These results provide a first step to a better understanding of the molecular formation of nanoplaques in blood vessels. The goal of this work is to open a way towards biosensing of the initial stages in atherogenesis allowing for a risk assessment in cardiovascular disease.
authors.affiliation: Institut für Physiologie, Charité-Universitätsmedizin Berlin, 14195 Berlin, Germany. miguel.rodriguez@charite.de
authors.forename: Miguel
authors.initials: M
authors.lastname: Rodríguez
authors.forename: Albrecht
authors.initials: A
authors.lastname: Lindinger
authors.forename: J Luis
authors.initials: JL
authors.lastname: Pérez Lustres
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Kovalenko
authors.forename: Nikolaus P
authors.initials: NP
authors.lastname: Ernsting
authors.forename: Ludger
authors.initials: L
authors.lastname: Wöste
authors.forename: Günter
authors.initials: G
authors.lastname: Siegel
mesh_terms: D000595:Amino Acid Sequence; D001161:Arteriosclerosis / Q000097:blood* / Q000473:pathology; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002118:Calcium / Q000494:pharmacology; D019812:Heparan Sulfate Proteoglycans / Q000097:blood* / Q000737:chemistry; D007834:Lasers; D008969:Molecular Sequence Data; D011487:Protein Conformation / Q000187:drug effects; D011973:Receptors, LDL / Q000097:blood; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014364:Tryptophan / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D019812:Heparan Sulfate Proteoglycans; D011973:Receptors, LDL; D014364:Tryptophan; D002118:Calcium