Global and target analysis of time-resolved spectra

In (bio)physical/(bio)chemical research time-resolved spectroscopy is used to disentangle complex kinetics. To fully extract the information from the overwhelming amount of data that is generally obtained, a model based analysis is mandatory. This analysis is based upon assumptions regarding the measurement process, and upon a physico-chemical model for the complex system. This model is composed of building blocks representing scientific knowledge and assumptions. Building blocks are the instrument response function, the components of the system connected in a kinetic scheme, and additional properties of the components (e.g. anisotropy). The use of a combined model for the kinetics and for the spectra of the components results in a more powerful spectro-temporal model. The model parameters, like rate constants and spectra, can be estimated from the data, thus providing a concise description of the complex system dynamics.

Contact: Dr. I.H.M. van Stokkum; e-mail: ivo@nat.vu.nl

Dept. of Physics and Astronomy

Fig. 1: Flow chart of modeling the initial photocycle of Photoactive Yellow Protein (PYP). Traces at 4 wavelengths are shown at the top right. The kinetic model scheme comprises of five states (indicated by the color of the box), of which the Species Associated Spectra (SAS) and rate constants have been estimated.