Robert Pascal

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The V2 vasopressin receptor is a G-protein-coupled receptor that regulates the renal antidiuretic response. Its third intracellular loop is involved in the coupling not only with the GalphaS protein but also with gC1qR, a potential chaperone of G-protein-coupled receptors. In this report, we describe the NMR solution structure of the V2 i3 loop under a(More)
In this study, we investigated the mechanism by which a peptide mimicking the third cytoplasmic loop of the vasopressin V2 receptor inhibits signaling. This loop was synthesized as a cyclic peptide (i3 cyc) that adopted defined secondary structure in solution. We found that i3 cyc inhibited the adenylyl cyclase activity induced by vasopressin or a(More)
α-Amino acids are easily accessible through abiotic processes and were likely present before the emergence of life. However, the role they could have played in the process remains uncertain. Chemical pathways that could have brought about features of self-organization in a peptide world are considered in this review and discussed in relation with their(More)
Bridging between the phenomenologically distinct biological and physical worlds has been a major scientific challenge since Boltzmann's probabilistic formulation of the second law of thermodynamics. In this review we summarize our recent theoretical attempts to bridge that divide through analysis of the thermodynamic-kinetic interplay in chemical processes(More)
In this paper we propose a logical connection between the physical and biological worlds, one resting on a broader understanding of the stability concept. We propose that stability manifests two facets - time and energy, and that stability’s time facet, expressed as persistence, is more general than its energy facet. That insight leads to the logical(More)
The conceptual divide separating the physical and biological sciences continues to challenge modern science. In this perspective it is proposed that the two sciences can be directly connected through the fundamental concept of stability. Physicochemical stability is shown to have a logical, rather than an empirical basis, and able to manifest itself in two(More)
Contents 1. Introduction 1.1. A workshop and this document 1.2. Framing origins of life science 1.2.1. What do we mean by the origins of life (OoL)? 1.2.2. Defining life 1.2.3. How should we characterize approaches to OoL science? 1.2.4. One path to life or many? 2. A Strategy for Origins of Life Research 2.1. Outcomes-key questions and investigations(More)
We propose a scenario for the dynamic co-evolution of peptides and energy on the primitive Earth. From a multi component system consisting of hydrogen cyanide, several carbonyl compounds, ammonia, alkyl amine, carbonic anhydride, borate and isocyanic acid, we show that the reversibility of this system leads to several intermediate nitriles, that(More)