22.07.2013 Views

Principles of Fluorescence Spectroscopy

Principles of Fluorescence Spectroscopy

Principles of Fluorescence Spectroscopy

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

506 TIME-RESOLVED ENERGY TRANSFER AND CONFORMATIONAL DISTRIBUTIONS OF BIOPOLYMERS<br />

P14.2. Describe the intensity decay law <strong>of</strong> sample B,<br />

including the decay times, pre-exponential factors<br />

(α i ) and fractional intensity (f i ) values. Assume each<br />

protein is present in equimolar amounts.<br />

P14.3. For the three-acceptor protein (sample A), could<br />

you detect the presence <strong>of</strong> three acceptors from the<br />

intensity decay?<br />

P14.4. For the three-acceptor protein what is the apparent<br />

D–A distance if you assumed the presence <strong>of</strong> a single<br />

acceptor?<br />

P14.5. Acceptor Concentration for FRET for Unlinked<br />

D–A Pairs:<br />

(a) Suppose you have a donor and acceptor that are<br />

not covalently linked, and that the Förster distance<br />

is 30 Å. Calculate the acceptor concentration<br />

needed to place, on average, one acceptor<br />

within a 60-Å cube containing a donor at the<br />

center. To a first approximation this concentration<br />

is comparable to that for 50% energy transfer.<br />

Compare this acceptor concentration with<br />

that calculated using eq. 13.33.<br />

(b) Consider a D–A pair covalently linked by a 30-<br />

Å linker. Calculate the effective concentration<br />

<strong>of</strong> acceptors around the donor.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!