The main reason green fluorescent protein (GFP) is so useful in molecular imaging is the fact that its chromophore is
formed autocatalytically. We have been using molecular mechanics to examine chromophore formation since 1995 that
is well before the first crystal structures of GFP were solved. Our calculations have resulted in a number of predictions
that have been borne out by subsequent experiments and a number of them that haven't. Recently we have been
supplementing these calculations with calculations based on the crystal structures of immature GFP mutants (i.e. the
precyclized form). Preliminary results from these calculations have shown that immature GFP does form a tight-turn in
the chromophore forming region, and that chromophore cyclization is probably catalyzed in the manner proposed by
Getzoff et al (Biochemistry 44: 1960-1970, 2005).
GFP is extensively used in molecular imaging applications. Its fluorescence is due to a autocatalytically formed
chromophore located in the center of the protein. Yellow and blue fluorescent mutants of GFP have been created. The
protein matrix that surrounds the chromophore influences both the intensity and the wavelength of the fluorescence. We
have used conformational searching methods and molecular dynamics simulations to examine the &tgr; and &fgr; dihedral space
available to a freely rotating and pyramidalizing chromophore. The calculations have shown that there seems to be a
relationship between the quantum yield of the fluorescent protein and the dihedral &tgr; and &fgr; space available to the
chromophore. The bright YFP has less rotational space available to a freely rotating chromophore than does wild-type
GFP or BFP, which has the most rotational freedom.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.