ABSTRACT
Uncovering local structural dynamics and fluctuations in bio-
molecules is one of the main challenges of modern science, with
the aim of understanding how they are ultimately linked to the
biological activity, which often involves global large-scale and thus
slower motion of their structure. Strictly related to local and global
fluctuations, the mechanisms of redistribution and dissipation of
excess of vibrational and electronic energy are at the center of
intensive studies aimed to understand, among all, the role they
play in, for example, intraprotein or protein-DNA signaling. This
chapter deals with the recent advances in ultrafast nonlinear
spectroscopy of proteins with a focus on the near-UV spectral
region. Here, the selective excitation and probing of natural amino
acids such as tryptophans and tyrosines provides great insight
into the molecular processes including energy and charge transfer
that trigger the biological processes. Examples from retinal and
heme proteins illustrate the wealth and precision of information
provided by these spectroscopic approaches. The most recent
advances in two-dimensional femtosecond near-UV spectroscopy
are discussed underscoring the great potential of this technique for
multichromophore systems such as proteins and DNA.
