American Chemical Society

Résumé

L'American Chemical Society (ACS) (« Société américaine de chimie ») est une société savante basée aux États-Unis active dans le domaine de la recherche scientifique en chimie. Historique Fondée en 1876, l'American Chemical Society compte actuellement plus de dans tous les domaines de la chimie et du génie chimique. Elle organise deux congrès par an aux États-Unis couvrant toute la chimie, ainsi qu'un grand nombre de congrès moins importants sur des sujets plus spécifiques. L'American Chemical Society comporte également un département éducation qui produit des tests de niveau standards dans de nombreux domaines de la chimie. Elle commandite également les Olympiades nationales de chimie des États-Unis, qui sélectionnent l'équipe de quatre étudiants représentant les États-Unis aux Olympiades internationales de chimie. Il s'agit actuellement de la plus riche société savante au monde, avec un chiffre d'affaires de d'euros réalisés en 2011. Elle possède une cagnotte de d'e

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https://fr.wikipedia.org/wiki/American_Chemical_Society

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Publications associées (100)

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Séances de cours associées (28)

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Controlling polymer architecture in the thermal hyperbranched polymerization of L-lysine

Harm-Anton Klok, Markus Scholl

Because of the unequal reactivity of the two amine groups of L-lysine hydrochloride, thermal polymerization of this asymmetrical AB2 monomer results in hyperbranched polymers, which contain ?2.5 times more N?-linked linear compared to N?-linked linear structural units. This report discusses the feasibility of three approaches to control polymer architecture during the thermal hyperbranched polymerization of L-lysine hydrochloride. The reactivity of the more reactive ?-NH 2 group was modulated by introducing temporary protective groups that preferentially block the ?-NH2 position. This was achieved by (i) addition of o-vanillin to the polymerization, (ii) copolymerization of N?-benzylidene-L-lysine, and (iii) copolymerization of ?-amino-?-caprolactam. Analysis of the degree of branching (DB) and the average number of branches (ANB) of the obtained polymers did not provide evidence for any significant structural changes. Analysis of the distribution of structural units, in contrast, revealed major structural changes and indicated a rearrangement from N?-linked linear structural units to N ?-linked linear structural units upon addition of o-vanillin and N?-benzylidene-L-lysine. Unlike o-vanillin and N ?-benzylidene-L-lysine, ?-amino-?-caprolactam was found to be rather ineffective in modulating polymer architecture. © 2007 American Chemical Society.

2007

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Computational Alanine Scanning Mutagenesis: MM-PBSA vs TI

Marta Andreia Da Silva Perez

Understanding protein-protein association and being able to determine the crucial residues responsible for their association (hot-spots) is a key issue with huge practical applications such as rational drug design and protein engineering. A variety of computational methods exist to detect hot-spots residues, but the development of a fast and accurate quantitative alanine scanning mutagenesis (ASM) continues to be crucial. Using four protein-protein complexes, we have compared a variation of the standard computational ASM protocol developed at our group, based on the Molecular Mechanics/Poisson- Boltzmann Surface Area (MM-PBSA) approach, against Thermodynamic Integration (TI), a well-known and accurate but computationally expensive method. To compare the efficiency and the accuracy of the two methods, we have calculated the protein-protein binding free energy differences upon alanine mutation of interfacial residues (ΔΔGbind). In relation to the experimental ΔΔGbind values, the average error obtained with TI was 1.53 kcal/mol, while the ASM protocol resulted in an average error of 1.18 kcal/mol. The results demonstrate that the much faster ASM protocol gives results at the same level of accuracy as the TI method but at a fraction of the computational time required to run TI. This ASM protocol is therefore a strong and efficient alternative to the systematic evaluation of protein-protein interfaces, involving hundreds of amino acid residues in search of hot-spots. © 2013 American Chemical Society.

2013

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In this study, we present a detailed characterization of the full α/β interface in the farnesyltransferase (FTase) enzyme, an important target in drug design efforts. This characterization is presented in terms of hot spots, warm spots, and null spots and is based on the application of an improved variation of the computational alanine scanning mutagenesis methodology, complemented with extensive solvent-accessible surface area and interfacial hydrogen-bonding analysis. A total of 130 interface amino acid residues were considered in this analysis, a number that represents 16.0% of the total of 814 amino acid residues in the full enzyme. Globally, the results provide important clues on the most important structural and energetic determinants for dimer formation, suggesting several key targets at the subunit interface for the development of new molecules that aim to inhibit FTase activity through blocking the formation of the fully active FTase dimer, yielding useful indications for future drug design efforts. © 2011 American Chemical Society.

2011

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