LABORATORY OF BIOPHYSICS AND PHOTOPHARMACOLOGY
- Overview
- Assessment methods
- Learning objectives
- Contents
- Full programme
- Bibliography
- Teaching methods
- Contacts/Info
The course aims to be self-consistent. A basic preparation in the semi-classical theory of electronic-state transitions, as well as notions of basic optics, thermodynamics and detectors physics will also be helpful, although not propaedeutic.
The students will be assigned one of the three experiments of the second section on which they will be required to prepare a synthetic scientific report detailing the objectives, materials and experimental procedures applied, data and data analysis, concluding remarks as well as a short presentation (15 min). They will be also required to prepare a report of the experiment afforded in the third section in the format of a scientific article with abstract, introduction, materials and methods, results and discussion, conclusions, references. The elaborates will be corrected and an oral colloquium will be held in which they will be overviewed and discussed, the student will give a talk on her/his presentation, and stand a question time.
The following aspects will be examined in order to define the mark:
• The attitude of the student during lab work (5 points)
• The clarity and technical soundness of the reports (8 points)
• The comprehension of the physical aspects underlying the addressed phenomena (6 points)
• The clarity and technical soundness of the talk (5 points)
• The ability of addressing the questions arising from discussion of the reports and talk 3 points)
• The knowhow matured on the technical aspects of the exploited techniques and on the instrumentation (6 points)
Full mark with laude will be attributed to students whose final score exceeds 30 points.
The main aims of the course are:
- developing in the students the knowledge and understanding of the working principles of selected spectroscopic techniques;
- evidencing their usefulness in characterization of biomolecular and pharmacological principles;
- examining critically exemplary papers from the existing literature;
- analysing the relationships between thermodynamics, biomolecular chemistry and metabolism;
- analysing the relationships between conformational dynamics of biomolecules and their spectral properties;
- modelling binding reactions;
- applying the learnt experimental techniques and models to elucidate the features of biomolecular systems;
- developing the ability to set-up an experimental scheme and to process experimental data;
- maturing the ability to summarize the experimental activity in a written report and an oral presentation.
At the end of the course, the students will inherit a comprehensive panorama of some of the most advanced fluorescence spectroscopic techniques used in modern molecular biophysics, and an operational expertise in some of such techniques, including time-correlated single photon counting, fluorescence correlation spectroscopy, photon counting histogram and single-molecule fluorescence resonance energy transfer. Moreover, they will gain some insight on the molecular mechanisms governing life and on the physical laws on which they are based. Finally, they will have the occasion to improve their data acquisition and analysis skills and to learn how to select, within a panel of options, the most suitable model to describe a complex physical phenomenon. Their communication skills will also benefit from the occasion of taking on the scientific reports and oral presentation required in order to stand the exam.
The course will be divided in three sections. The first one will consist in a series of introductory seminar-lectures (20 h) in which:
- a semi-quantitative excursus on light-matter interactions, focused on the investigation of molecular electron-state transition with particular care to fluorescence spectroscopy will be undertaken
- an introduction on the themes of chemical binding and conformational transitions and on their importance in epigenetics and metabolic regulation will be afforded
- a cartoon representation of the chemical structure and conformational features of nucleic acids and proteins will be sketched
- an idea of the basics of molecular biology (genetic code and protein synthesis in pills) will be given
-- the molecular principles underlying the biological activity of selected drug substances will be explained
- the role of physics and the contributions of physical scientists to the progress of knowledge and comprehension of biological systems
During the second section the students will undertake experimental activities and familiarize with the practical application of the studied techniques working on a panel of well-characterized model systems (30 h).
Namely, they will investigate the binding of an antitumor drug to DNA by:
• Preparing the sample solutions to be analyzed
• Submitting these solutions to three different spectroscopic analyses: steady state absorption, steady state fluorescence, and time-resolved fluorescence
• Analyzing the data to extract the binding parameters and comparing the results yielded by the three techniques
Moreover, the will monitor the aggregation dynamics of either a pharmaceutical active principle or an amyloid protein through fluorescence fluctuation spectroscopy.
Finally, they will exploit single-molecule fluorescence energy transfer to characterize the folding equilibrium of an exotic DNA structure, namely a promotorial G-quadruplex, at varying the buffer composition (i.e.: the properties of the biomolecule’s environment).
In the third section (16 h) the students will be faced with an experiment excerpted from the current research activity of the teacher, and will be asked to acquire some measurements on a previously uncharacterized system and to cope with unpredicted experimental issues.
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Excerpts from three textbooks will be advised, namely:
C. Cantor, P. Schimmel: Biophysical Chemistry – Part 2, chapter 7: Absorption spectroscopy (pp. 343 -408)
J. R. Lakowicz: Principles of fluorescence spectroscopy – Chapters 1 and 4
J. D. Watson et al.: Molecular biology of the gene – Chapters 1-3.
However, the slides of the lectures will be readily made available on the e-learning web portal, and they intend to be sufficient to prepare the exam.
Moreover, research papers and tutorial reviews will be selected and provided to the students, including historical works in which the topics exploited in the course were first addressed (e.g.: original works by Watson and Crick on the DNA structure and genetic code, pivotal papers of Scatchard, McGhee and Von Hippel on binding models, articles by Webb, Rigler and Ha on fluorescence fluctuation spectroscopy and single-molecule fluorescence techniques, etc.).
Other advised readings are the following:
Erwin Schrodinger “Che cos’è la vita?” Adelfi
James D. Watson “La doppia elica” Adelfi
The introductory lectures will be as interactive as possible and, although slides will be used with the intention to give a reference frame of the fundamental competences to be acquired, discussions and digressions arising from the student personal experiences and curiosity will be encouraged. Moreover, if the number of students will allow this solution, they will be kept in the lab and interspersed with experimental demonstrations.
The experimental activities will be afforded in groups of three/four students and supervised by the teacher. However, an active involvement of the students in finding the most suitable technical solutions to the issues they will encounter will be fostered and independency will be sought.
The teacher can be contacted by e-mail at the address or by phone.