Studies of luminescent conjugated polythiophene derivatives: enhanced spectral discrimination of protein conformational states.
Improved probes for amyloid fibril formation are advantageous for the early detection and better understanding of this disease-associated process. Here, we report a comparative study of eight luminescent conjugated polythiophene derivates (LCPs) and their discrimination of a protein (insulin) in the native or amyloid-like fibrillar state. For two of the LCPs, the synthesis is reported. Compared to their monomer-based analogues, trimer-based LCPs showed significantly better optical signal specificity for amyloid-like fibrils, seen from increased quantum yield and spectral shift. The trimer-based LCPs alone were highly quenched and showed little interaction with native insulin, as seen from analytical ultracentrifugation and insignificant spectral differences from the trimer-based LCP in buffered and native protein solution. Hence, the trimer-based LCPs showed enhanced discrimination between the amyloid-like fibrillar state and the corresponding native protein.
Aslund
Andreas
A
Chemistry, IFM, Linköping University, SE-581 83, Linköping, Sweden.
Herland
Anna
A
Hammarström
Per
P
Nilsson
K Peter R
KP
Jonsson
Bengt-Harald
BH
Inganäs
Olle
O
Konradsson
Peter
P
D000818:Animals; D002417:Cattle; D007328:Insulin / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013876:Thiophenes / Q000138:chemical synthesis / Q000737:chemistry*; D017186:Titrimetry; D014461:Ultracentrifugation
D007328:Insulin; D011108:Polymers; D013876:Thiophenes; C066730:polythiophene