Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Cooperativity principle

In an effort to apply the cooperative principles of metalloenzyme reactivity, involving a combination of metal-ligand and hydrogen bonding, we have reported a ruthenium catalyst incorporating imidazolyl phosphine ligands that efficiently and selectively hydrates terminal alkynes (5). We subsequently found that application of pyridyl phosphines to the reaction resulted in a >10-fold rate enhancement and complete anti-Markovnikov selectivity, even in the... [Pg.237]

I. S. Cooper, Principles and Rationale of Cryogenic Surgery, St. Barnabas Hasp. Med. Bull., 1, 5... [Pg.36]

Mej S -O, which is pyramidal and hence has an exposed dipole, produces the largest shift whereas non-dipolar solvents such as hexane or tetra-chloromethane (CCI4) are treated as causing zero shifts for condensed systems such as these. Often, the shifts are to lower frequencies when hydrogen bonds form, as in this case. The shift from zero is proportional to the total H-bond strength, but the individual shifts decrease as the number of bound water molecules increases. This is another example of the anti- cooperativity principle. [Pg.63]

The Organization for Economic Cooperation and Development (OECD) has been a proponent of the "polluter pays" principle. What is the principle and how can it be implemented ... [Pg.71]

Brock, H. R. Jennings, D. R. and Feiten, J. B. (1996). Petroleum Accounting Principles, Procedures and Issues, 4tli ed. Demon, TX Price Waterhouse Coopers, Professional Development Institute. [Pg.1014]

Note that there are, in principle, other ways to move molecules in a glass, in addition to the cooperative rearrangements for example, by creating defects such as vacancies (the corresponding barriers are prohibitively high, of course). [Pg.122]

Cooper RJ, Hoffman JR, Bartlett JG, et al. Principles of appropriate antibiotic use for acute pharyngitis in adults Background. Ann Intern Med 2001 134(6) 509-517. [Pg.1074]

This study supports rate-determining H-OH bond breaking, which constrasts with previous reports that identified vinylidene isomerization as the key step in catalytic alkyne activation. The results indicate an enzyme-like mechanism is operative involving cooperative substrate activation by a metal center and proximal hydrogen bond donor/acceptors. In the future we will apply these principles to the activation of additional species. [Pg.240]

Purpose T1D-RAID is a cooperative program of the NIDDK and NCI that is designed to facilitate translation to the clinic of novel, scientifically meritorious, therapeutic interventions for the treatment of Type-1 diabetes. The goal of T1D-RAID is to support the pre-clinical tasks needed for the clinical "proof of principle" to determine if a new molecule merits... [Pg.372]

The MWC model says that in the R state, all the active sites are the same and all have higher substrate affinity than in the T state. If one site is in the R state, all are. In any one protein molecule at any one time, all subunits are supposed to have identical affinities for substrate. Because the transition between the R and the T states happens at the same time to all subunits, the MWC model has been called file concerted model for allosterism and cooperativity. The MWC model invokes this symmetry principle because the modelers saw no compelling reason to think that one of the chemically identical subunits of a protein would have a conformation that was different from the others. Alternative models exist that suggest that each subunit can have a different conformation and different affinities for substrate. Experimentally, examples are known that follow each model. [Pg.132]


See other pages where Cooperativity principle is mentioned: [Pg.231]    [Pg.231]    [Pg.28]    [Pg.231]    [Pg.231]    [Pg.28]    [Pg.268]    [Pg.75]    [Pg.268]    [Pg.1440]    [Pg.4]    [Pg.483]    [Pg.201]    [Pg.412]    [Pg.1338]    [Pg.69]    [Pg.350]    [Pg.273]    [Pg.251]    [Pg.96]    [Pg.193]    [Pg.24]    [Pg.493]    [Pg.1080]    [Pg.39]    [Pg.52]    [Pg.52]    [Pg.27]    [Pg.119]    [Pg.132]    [Pg.158]    [Pg.115]    [Pg.295]    [Pg.119]    [Pg.118]    [Pg.181]    [Pg.463]    [Pg.102]   


SEARCH



© 2024 chempedia.info