Taylor cycle

To date, three primary conformations of the myosin crossbridge that can be associated with states in the Lymn-Taylor cycle have been identified. These have been named the post-rigor structure (Fig. 2 and state 2 in Fig. 1), the pre-powerstroke structure (corresponding to the myosin products complex, M.D.P , state 3 in Fig. 1), and the rigor Iihe (or rigor structure if it is associated with actin) state (shown as state 1 in Fig. 1). A comparison of these structures leads to the identification the following important conformationally flexible elements ... 

Goureux et al. (2004) discuss the differences among rigor-like, postrigor, and pre-powerstroke states in detail. Their conclusions are based on the crystallographic structures of myosin V with and without bound nucleotide. We use a somewhat simplified scheme to describe the differences and similarities among the three conformers of myosin that we have identified as being represented in the Lymn-Taylor cycle. These are summarized in Table I. 

The apparent positions in the Lymn-Taylor cycle of the structural states that we refer to as the pre-powerstroke, rigor-like, and post-powerstroke conformations are shown in Fig. 10. Thus it appears that three of the four... 

Fig. 10. The structural correlates of the Lymn-Taylor cycle. Numbering of states as in Fig. 1A. See Section IV for a detailed description.

Myosin II is a molecular motor responsible for muscle contraction and intracellular cargo transport [44]. It uses the hydrolysis of ATP to drive the Lymn-Taylor cycle, which describes the cyclic interactions between myosin and the actin filament that produce motion (Figure 17.3). Induced fit during steps I->II->-III... 

I first became interested in the subject of cycles when I went on sabbatical leave to MIT, from Cambridge England to Cambridge Mass. There I was asked by the Director of the Gas Turbine Laboratory, Professor E.S.Taylor, to take over his class on gas turbine cycles for the year. The established text for this course consisted of a beautiful set of notes on cycles by Professor (Sir) William Hawthorne, who had been a member of Whittle s team. Hawthorne s notes remain the best starting point for the subject and I have called upon them here, particularly in the early part of Chapter 3. 

Min GR, Edwards RL, Taylor FW, Recy J, Gallup CD, Beck JW (1995) Annual cycles of U/Ca in corals and U/Ca thermometry. Geochim Cosmochim Acta. 59 2025-2042 Moore WS (1981) The thorium isotope content of ocean water. Earth Planet Sci Lett 53 419-426 Moran SB, Hoff JA, Edwards RL, Landing WM (1997) Distribution of Th-230 in the Laborador Sea and its relation to ventilation. Earth Planet Sci Lett 150 151-160 Muhs DR, Simmons KR, Steinke B (2002) Timing and warmth of the Last Interglacial period new U-series evidence from Hawaii and Bermuda and a new fossil compilation for North America. Qrrat Sci Rev 21 1355-1383... 

G. H. Taylor, Biogeochemistry of Uranium Minerals, in Biogeochemical Cycling of Mineral Forming Elements, P. A. Trudinger and D. J. Swaine, eds., Elsevier, Amsterdam, p. 485,1979. 

Cuthbertson KS, Whittingham DG, Cobbold PH 1981 Free Ca2+ increases in exponential phases during mouse oocyte activation. Nature 294 754—757 Day ML, Johnson MH, Cook DI 1998 A cytoplasmic cell cycle controls the activity of a K+ channel in pre-implantation mouse embryos. EMBO J 17 1952—1960 Flach G, Johnson MH, Braude PR, Taylor RA, Bolton VN 1982 The transition from maternal to embryonic control in the 2-cell mouse embryo. EMBO J 1 681-686 Howlett SK 1986 A set of proteins showing cell cycle-dependent modification in the early mouse embryo. Cell 45 387-396... 

Indermuhle A, Stocker TF, Joos F, Fischer H, Smith UJ, Wahlen M, Deck B, Mas-troianni D, Tschumi J, Blunier T, Meyer R, Stauffer B. Holocene carbon-cycle dynamics based on C02 trapped in ice at Taylor Dome, Antarctica. Nature. 1999 398 121-126. 

FIGURE 26.1 Dioxygenase cycle 15-LOX. (From YB O Donnell, KB Taylor, S Parthasarathy, H Kuhn, D Koesling, A Friebe, A Bloodsworth, VM Darley-Usmar, BA Freeman. J Biol Chem 274 20083-20091, 1999. With permission.)... 

Missiaen L, Taylor CW, Berridge MJ 1992 Luminal Ca2+ promoting spontaneous Ca2+ release from inositol trisphosphate-sensitive stores in rat hepatocytes. J Physiol 455 623-640 Nazer MA, van Breemen C 1998 Functional linkage of Na+-Ca2+ exchange and sarcoplasmic reticulum Ca2+ release mediates Ca2+ cycling in vascular smooth muscle. Cell Calcium 24 275-283... 

Rice, R. H., K. E. Steinmann, L. A. deGraffenried, Q. Qin, N. Taylor, and R. Schlegel. 1993. Elevation of cell cycle control proteins during spontaneous immortalization of human keratinocytes. Mol Biol Cell 4(2) 185-94. 

Figure 16.1 a schematic representation illustrating the chemical reactions that interconvert small molecules in cells. Each dot represents a compound and the lines that connect them represent reactions. The heavy dots and lines down the center of the maze reflect the glycolytic pathway and the heavy circle near the bottom of the maze reflects the citric acid cycle. ( 2007 From Molecular Biology of the Cell, 5th Edition, by Alberts et al. Reproduced by permission of Garland Science/Taylor Francis, EEC.)... 

Taylor and colleagues have published an 8-yr analysis of Rush Medical College s experience with stage in or IV patients that have received concomitant cisplatin (60 mg/m2, d 1), continuous infusion 5-FU (800 mg/m2, d 1-5), and single fraction radiation therapy (2 Gy) on d 1-5 (57). The cycle was repeated every other week for atotal of seven cycles. The sample size was small with 78 patients. Six weeks after initial therapy, 63% had no clinical evidence of disease, 37% had a partial response (PR). Overall, 31% of patients had recurred or progressed 24% died from nontumor-related causes. The 5-yr PFS was 60% in this small cohort of patients with an overall survival reported to be 43%. 

Bouwman, A. F., and J. A. Taylor, Testing High-Resolution Nitrous Oxide Emission Estimates against Observations Using an Atmospheric Transport Model, Global Biogeochem. Cycles, 10, 307-318 (1996). 

In experiments run over a number of cycles, the activity was observed to increase after the first cycle, unlike the y-A Os counterpart which deactivated. Using BN, no Pt sintering occurred and this was ascribed to the high thermal conductivity of BN, ensuring that no local hot-spots were formed. On the basis of XPS, the locus of Pt particle attachment was proposed to be surface boron oxide impurities. Taylor and Pollard have compared the activities of silica (194 m g ) and boron nitride (7 m g ) supported vanadium oxide catalysts for propane oxidation. The use of boron nitride was reported to significantly... 

Taylor, T. W. and Geiseler, W., 1986, Periodic operation of a stirred flow reaction with limit cycle oscillations. Ber. Bunsenges Phys. Chem. (submitted). 

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