Task 4 13 December 2012
Calculation of a Distance from FRET Data
The protein human serum albumin (HSA) has a
single tryptophan residue at position 214. HSA was
labeled with an anthraniloyl group placed covalently
on cysteine 34 (Fig.1). Emission spectra of the
labeled and unlabeled HSA are shown in Fig. 2. The
Förster distance for Trp to anthraniloyl transfer is
listed in Table 2 by your name. Use the values from
Table 1 derived from emission spectra in Fig. 2 to
calculate the Trp to anthraniloyl distance.
Table 1
1. What is the transfer efficiency between Trp 214 and anthraniloyl E for such
modified HSA? Calculate the E value to two decimal places.
2. What is the distance Trp 214 and anthraniloyl cysteine 34 calculated based on
fluorescence resonance energy transfer?
Indicate the distance value in Angstrems (Å) with precision to one decimal place.
Send me your answer via email. Correct answer = 1 point.
relative fluorescence
λ (340nm) λ (408nm)
HSA 0.546 0.091
mod HSA 0.202 0.687
Fig. 2
Fig. 1
Table 2
R0
(Å)
1 Bencúrová, Petra 28.9
2 Dabravolski, Siarhei 27.9
3 Dubec, Vít 29.2
4 Dudová, Zdenka 31.3
5 Dvořák, Jan 30.3
6 Fabišik, Matej 29.5
7 Fedorko, Jan 28.0
8 Fialová, Martina 28.4
9 Holek, Michal 31.1
10 Kočka, Martin 30.8
11 Míka, Matěj 30.6
12 Obacz, Joanna Agnieszka 28.5
13 Partyka, Jan 28.6
14 Přikrylová, Terézia 27.7
15 Rájecký, Michal 28.3
16 Reichman, Pavel 31.4
17 Sochorová, Jana 28.6
18 Škubník, Karel 28.4
19 Tylichová, Zuzana 30.5
This task was prepared base on Problem 1.6 on page 25 in Principles of fluorescence
spectroscopy (2006) book of Prof. Lakowicz.