2D spectroscopy of astaxanthin in solution and in carotenoprotein crustacyanin

This project is related to the following Fields, Subjects and Techniques:

Carotenoid astaxanthin undergo spectacular bathochromic shift when bound to the α-, β-crustacyanin proteins. These proteins are found in the carapace of lobsters and give them their characteristic color. The mechanism of spectral shift upon binding to crustacyanin is still not well understood, even though several molecular mechanisms were proposed: protonation and hydrogen bonding of astaxanthin keto groups or, alternatively, excitonic interaction between astaxanthin molecules in close proximity when bound to the protein. By using 2D spectroscopy we are going to investigate if excitonic coupling between astaxanthin plays a major role.

Structure of β-cruxacyanin carotenoprotein

Cianci, M. at al. PNAS 2002, 99, 9795.