Thermodynamic parameters for the helix-coil transition of oligopeptides: molecular dynamics simulation with the peptide growth method.

The helix-coil transition equilibrium of polypeptides in aqueous solution was studied by molecular dynamics simulation. The peptide growth simulation method was introduced to generate dynamic models of polypeptide chains in a statistical (random) coil or an alpha-helical conformation. The key element of this method is to build up a polypeptide chain during the course of a molecular transformation simulation, successively adding whole amino acid residues to the chain in a predefined conformation state (e.g., alpha-helical or statistical coil). Thus, oligopeptides of the same length and composition, but having different conformations, can be incrementally grown from a common precursor, and their relative conformational free energies can be calculated as the difference between the free energies for growing the individual peptides. This affords a straightforward calculation of the Zimm-Bragg sigma and s parameters for helix initiation and helix growth. The calculated sigma and s parameters for the polyalanine alpha-helix are in reasonable agreement with the experimental measurements. The peptide growth simulation method is an effective way to study quantitatively the thermodynamics of local protein folding.

On the distribution of amino acid residues in transmembrane alpha-helix bundles.

The periodic distribution of residues in the sequence of 469 putative transmembrane alpha-helices from eukaryotic plasma membrane polytopic proteins has been analyzed with correlation matrices. The method does not involve any a priori assumption about the secondary structure of the segments or about the physicochemical properties of individual amino acid residues. Maximal correlation is observed at 3.6 residues per period, characteristic of alpha-helices. A scale extracted from the data describes the propensity of the various residues to lie on the same or on opposite helix faces. The most polar face of transmembrane helices, presumably that buried in the protein core, shows a strong enrichment in aromatic residues, while residues likely to face the fatty acyl chains of lipids are largely aliphatic.

Quality of Democracy in Quadruple Helix Structures: The Quality of Democracy in the United States and in Austria, Challenges and Opportunities for Development. ACES Working Papers, 2012

This contribution focuses on analyzing the quality of democracy of the United States (U.S.) and of Austria by using a comparative approach. Even though comparisons are not the only possible or legitimate method of research, this analysis is based on the opinion that comparisons provide crucial analytical perspectives and learning opportunities. Following is the proposition, put directly forward: national political systems (political systems) are comprehensively understood only by using an international comparative approach. International comparisons (of country-based systems) are common (see the status of comparative politics, for example in Sodaro, 2004). Comparisons do not have to be based necessarily on national systems alone, but can also be carried out using “within”-comparisons inside (or beyond) sub-units or regional sub-national systems, for instance the individual provinces in the case of Austria (Campbell, 2007, p. 382).

Planetary cartography in the next decade (1984-1994) /

Mode of access: Internet.

Comptes rendus de l'Académie des sciences. Earth & planetary sciences

Mode of access: Internet.

Planetary geosciences--1988 /

Mode of access: Internet.

Planetary geosciences, 1989-1990 /

Mode of access: Internet.

Planetary exploration through year 2000 : a core program executive summary : part one of a report /

Mode of access: Internet.

Other worlds from earth : the future of planetary astronomy : a report of the Planetary Astronomy Committee of the Solar System Exploration Division.

Shipping list no.: 89-402-P.

Exploring Mars and beyond : what's next for U.S. planetary science : hearing before the Subcommittee on Space and Aeronautics, Committee on Science, Space, and Technology, House of Representatives, One Hundred Twelfth Congress, first session, Tuesday, November 15, 2011.

Mode of access: Internet.

Atlas (1900-1959) of planetary solar climate, with sun-tide indices of solar radiation and global insolation.

Mode of access: Internet.

History of the planetary systems from Thales to Kepler,

Mode of access: Internet.

The planetary product "back to normalcy" in 1976-77.

Includes bibliographical references.

Cursus medicus xenodochii matritensis : in quo norma servanda in publicis oppositionis lectionibus proponitur, perutilis pr[a]edicendi modus explicatur, reformatio multorum medicamentorum continetur, & multae priscorum nebulae relegantur ... /

Palau,