WS 14/15 Modern Methods in Experimental Physics

Site-directed spin labeling EPR

The course gives an introduction to electron paramagnetic resonance (EPR) spectroscopy, with special focus on site-directed spin labeling (SDSL) for the study of biomolecules. SDSL EPR is a biophysical technique providing structural and dynamic information on proteins to bridge the gap between the static snapshot of a crystal structure and the protein’s dynamic nature in a physiological environment. At the beginning of the course a brief introduction on amino acids and protein's primary-tertiary structures will be provided. The course will then start from a general description of the magnetic resonance phenomena: classical description and Bloch equations, quantum description of the spin system, spin Hamiltonian, density operators, product operator formalism (spin 1/2). The nitroxide-based spin labels available for protein studies are presented and the properties of their continuous wave EPR spectra are described in detail with focus on the dynamics and polarity effects on the spectral features and the multi-frequency advantage. Continuous wave and pulsed methods to measure interspin distances are described. A schematic description of continuous wave and pulsed spectrometers is given. State of the art applications of SDSL EPR to water soluble and membrane proteins are presented at the end of the course.

Exercises will cover the theoretical aspects presented in the course and two lab courses may be offered (to be decided with the students) on continuous wave or pulsed EPR techniques.

Lectures: Mondays from 12:00 to 14:00 in room 1.1.16

Slides and additional material will be provided during the lecture. Selected material can be also found here (registered students: please send me an e-mail and you will get access)

Lecture	Material
13/10	Introduction: why using EPR to study proteins? part_A part_B
10/11	Exchange phenomena
08/12	Spins of metals
09/12	Single crystal and g tensor Direct product for coupled spins Lecture notes
15/12	Nuclear isotope database (from Easyspin)
05/01	H_hf_nq_zfs
12/01	H_exch_dip
19/01	Product_Operator_Formalism
09/02	site-directed_spin_labeling_part_I site-directed-spin-labeling_part_II

Exercises: Tuesdays from 14:00 to 16:00 in room 1.1.16. Note that on 14/10/2014 there will be no exercises. The exercises will start on 21/10/2014.

Exercises and solutions will be available here. (Registered students: please send me an e-mail and you get access)

ex. number	exercise online	hand in by	solution online
ex_01	22.10.2014	27.10.2014	sol_1
ex_02	30.10.2014	03.11.2014	sol_2
praktikum CW EPR	16.12 12:00-18:00 Room 0.4.40
ex_03	27.11.2014	01.12.2014	sol_3
ex_04	22.01.2015	02.02.2015	sol_4
praktikum DEER	06.02.2015 11:00-19:00 Room 0.4.40
ex_05	sol_05

if you are interested in the EPR summer school 2015: http://www.helmholtz-berlin.de/events/efepr/index_de.html

Physik • Freie Universität Berlin

Physik • Freie Universität Berlin

WS 14/15 Modern Methods in Experimental Physics