Pier Luigi Luisi came to the ETH-Zürich in
1970 and developed here his professional career, becoming ordinarius in
“Macromolecular Chemistry” in the early 80ties. His group was located within
the Institute of Polymers (“Institut für Polymere”, IfP), which he
helped grounding together with Prof. Piero Pino (his mentor) and Prof.
Joachim Meissner, an Institute which is now part of the department of Materials
Sciences of the ETH-Zürich. Within IfP, Luisi developed a “Biopolymer
group” at the interface between the Department of Materials Sciences and
the Department of Chemistry. Luisi was the Chair (“Vorsteher”) of
the Chemistry Department in 1996-1998.
Initially (1970-1980), the research activity of Luisi’ group
concerned with the synthesis and conformation of peptides (Rizzo
& Luisi,1977; Rizzo
et al,1977; Skrabal
et al,1979; Wolf
& Luisi,1979). Peptides were also prepared by the help of
proteases by reverse hydrolysis reactions (Anderson
&
Luisi,1979; Luisi
et al, 1979). In these first years also the study of the mechanism
of action of dehydrogenases was in the focus of the research activity (Joppich-Kuhn
& Luisi,1978 ; Abdallah
et al, 1978). In the field of enzymology, the group developed
new techniques of rapid kinetics (stopped-flow), as well as of fluorescence.
A second phase of the work of the group started in 1980
ca. and concerned the self-assembly of surfactant aggregates. The
interest for this field can be understood on the basis of the illustration
below:
To this period belong the studies on enzymes in
reverse micelles, a field on which the group has done pioneering
work. Some of the most cited references of Luisi’ group still go back to
this period (
Grandi
et al, 1981; Luisi
& Laane, 1986; Luisi
& Majid, 1986; Luisi
& Straub,1984; Luisi
et al,1988). In this period, Peter Walde joined Luisi’s group and his
collaboration was instrumental in developing the field of enzymes in reverse
micelles, self-reproduction of micelles, and later on the field of
vesicles. The field of reverse micelles (RM) was typically at the interface
between basic science and biotechnology (applications of enzymes or protein
separation (Pfammatter
et al, 1992) and/or micro-organisms in organic solvents(Pfammatter
et al,1992; Famiglietti
et al,1992). Also DNA as well as plasmids or entire ribosomes could
be brought into the water pool of RM (Imre
& Luisi,1982 ; Palazzo
& Luisi,1992).
The work on reverse micelles brought by serendipity to the discover
of lecithin organogels (Scartazzini
& Luisi,1988; Capitani
et al,1988; Haering
& Luisi,1986; Schurtenberger
et al,1989) which were developed into patents. Lecithin organogels
have been studied in the group as matrices for the transdermal transport
of drugs (Willimann
et al,1992; Willimann
& Luisi,1991) in collaboration with the pharmaceutical Company
Inpharzam/Zambon at Cadempino, Switzerland. The structure of lecithin gels
has been then studied independently by Peter Schurtenberger’s group, initially
located within Luisis’ group and now professor of physical chemistry at
the University of Fribourg, Switzerland.
To this second phase belongs also the work on cubic phases, which
were studied as transparent matrices for proteins (Portmann
et al,1991; Landau
& Luisi,1993) This work was later on developed independently by
Dr. Ehud Landau at the Biozentrum in Basel.
The interest of Luisi for biological question brought to
a collaboration with Francisco Varela, the proponent (together with Humberto
Maturana) of the notion of autopoiesis. A first theoretical paper on self-reproduction
autopoietic models based on micelles was developed (Luisi
& Varela, 1990), which was actually the origin of the studies of
the group on origin of life and self-reproduction. The theory of autopoiesis
has been extended by us so as to develop a minimal chemical autopoietic
system (Bachmann
et al, 1990; Luisi,1993
;
Bachmann
et al,1992).
In this relation, we have been involved in a study
of the definitions of life (Luisi,1998)
as well as in a study of the relation between the RNA-world
approach to the origin of life vis-a-vis the membrane-compartimentation
approach (Luisi,1993;
Luisi,1997;
Luisi,
2000; Luisi
et al,1999).
The main research activity of the group since ca. 1990 focuses on vesicles
and liposomes and their biological relevance, both in fundamental and applied
science. In particular, we are now known as one of the few European chemistry
groups working in the area of the origin of life.
The group consists now, in addition to Pier Luigi
Luisi, of three senior researcher, Peter Walde who obtained the title
of Titular-Professor of the ETH-Z in 1997; Matthias Voser, who is responsible
of the molecular biology in liposomes, including the project on minimal
cell (see below); and Richard M. Thomas who is a biophysicist specialized
in the application of spectroscopic techniques, including ultracentrifugation.
The group enjoys the secretary help of Mrs. Margrit Zeller and has in average
1-2 postdocs and 8-9 graduate students (Doktorandinnen und Doktoranden).
Pier Luigi Luisi is also responsible of the initiative Cortona-Week
(Cortona-Woche) , a program developed at the ETH-Z to foster the interdiscliplinarity
and the integration between science and humanities for academic students
and teachers.
The study of the origin of life is tantamount to
the study of the origin of molecular complexity - how the complex structures
of life - enzymes, nucleic acids, the cell, may have arisen from the very
simple organic and inorganic molecules that were produced on our Earth
by natural processes. Lipids, lipid aggregates and in particular liposomes
are used in our group under the working hypothesis that these self-organized,
compartmentalised structures may contribute to the construction of
higher molecular complexity
.
In particular, two complementary lines of research
are followed in the group, which are defined as bottom-up and top-down
approaches to the origin of life. In the bottom-up approaches, we start
from very simple, possibly prebiotic molecules, with the goal of
increasing step-wise the molecular complexity-up to tendentiously reaching
a working protocell. In this approach enzymes and nucleic acids cannot
be utilised, - as they were not existing at the beginning of the prebiotic
history. This approach, by which an increasing degree of complexity and
function specificity is obtained by progressive increase of the molecular
complexity, corresponds philosophically to the notion of emergence: about
this notion Pier Luigi Luisi has written an extensive review (in
press in “Foundation of Chemistry”).
We can presently delineate eight different projects, listed in the menu
to the left, carried out in the group along these lines of research. These
projects partly or largely overlap with each other and, we hope, give a
clear picture of the group’s activities and curiosity.