Page 119 - MemoriaBBN-Eng

www.ciber-bbn.es

diversification of mutant molecular populations. The objectives set by the group are

listed below:
•
Determination of the thermodynamics of nucleic acids to high resolution.
• Dynamic force spectroscopy and molecular imprinting methods.

• Thermodynamics of small systems and systems out of equilibrium.
• Molecular Motors.

• Experiments of molecular evolution and recognition with single molecule techniques.

• AlemAny A, sAnviCens n, de lorenzo s, mArCo mP, ritort F. Bond elasticity controls
Most relevant
molecular recognition specificity in antibody-antigen binding.Nano Lett. 2013 Nov
scientific 13;13(11):5197-202.

articles
• CAmunAs-soler, s. Frutos, C.v. BizArro, s. de lorenzo, m.e. Fuentes-Pérez, r. rAmsCh, s.
v, C. s, F. m-h, F. A, r. e, e. G, s.B. d F.
ilChezolAnsorenoerrerolBeriCioritJAirAltevAnd
ritort. Electrostatic binding and hydrophobic collapse of peptide-nucleic acid aggre-
gates quantified using force spectroscopyACS NANO. 2013;7(6): 5102-5113..

• m. m, s. K. P, P. B, F. r, s. J. B, v. C. RecG and
AnosAserumAliAnCoitortenKoviCroquette
UvsW catalyse robust DNA rewinding critical for stalled DNA replication fork rescue-
Nature Communications. 2013;4:1-11.

• m. r, J. m. h F. r. Counter-propagating dualtrap optical twee-
iBezziuGuetAnd itort
zers based on linear momentum conservationReview of Scientific Instruments.
2013;84:043104-1, 043104-10.

• A. BosCo, J. CAmunAs-soler And F. ritort. Elastic properties and secondary structure

formation of single-stranded DNA at monovalent and divalent salt conditionsNucleic
Acids Research. 2013;42(3):2064-74.

Last year the group has succeeded in studding several problems combining theory
Highlights
and experiments to investigate the thermodynamics and non-equilibrium behavior
of small systems using single molecule methods. By applying tiny forces in the

piconewton range we use high-resolution optical tweezers to manipulate single mo-
lecules and mechanically dissociate molecular bonds to measure the energies of

molecular reactions in nucleic acids, proteins and other molecular complexes with
accuracy of tenths of kcal/mol. We apply the finest concepts and tools from statisti-

cal physics to extract precious information characterizing a wide range of molecular
processes and phenomena: from the thermodynamics of nucleic acids to the kinetics

of formation of molecular aggregates induced by anticancer drugs or the elasticity of
antigen-antibody bonds in the immune system.

Motivated by my previous first experimental test of the Crooks fluctuation relation

we found a new relation that recently paved the way to extract the free energies of
kinetic states of finite lifetime in complex molecular structures. This work provides

a new and powerful methodology to characterize the energetics and kinetics of non- 13
native molecular structures (e.g. intermediate, misfolded) hardly accessible to most 20
T
bulk based techniques. We have extended such method to the full characterization OR
P
of intermolecular affinities between peptides and proteins binding to nucleic acids.
RE
Beyond fundament research in biophysics I have led several applied-research co- L
A
llaborations with chemistry and biology groups and a drug company (Pharmamar) NU
N
finding relevant results on the kinetics of DNA-peptide aggregation (Camunas-Soler A
et al) and the role of bond elasticity in antigen-antibody recognition (Alemany et N /
B
al). I have also developed a novel dual-trap counter-propagating setup for pulling -B
dumbbells with direct force measurement that can be used for pulling tethers with R
BE
very short DNA handles (Ribezzi et al). Finally, we have built a new highly stable CI
temperature controller for optical tweezers that allows us to face future challenges
119
in this exciting field.