COMPASS methylation

Fig. 14. A side view along the >> axis of bonding of cyclic Sis-siloxane molecules cage type and ladder type siloxane molecules at maximum possible occupancy on an a-quartz (001) surface (3x4 unit cell) after manual matching on the X-ray structure, followed by energy minimization with DISCOVER/COMPASS at periodic-boundary conditions, with cut-off radius 9.5 A (white vertical lines mark the computational box), a, c, e methyl derivatives, b, d, f iso-octyl derivatives, a, b cyclic Sis-siloxanes, c, d cage molecules (type VII according to Ref. [75]), e, f ladder molecules. Specifications of occupancy (per 3x4 unit cell), where A= number of bound siloxane molecules, R = number of aliphatic side-chains, F == number of remaining free OH groups on the quartz surface, E = bond enthalpy (kcal moP unit cell), a iV = 4, / = 12, F = 0, A = -319.5, b V = 4, F = 12, F= 0, AF = -1 50.9, c 4,F = 36, F= 8, A = -1950, d V= 1, A = 9, F= 11,...

Dover, J. et al. (2002). Methylation of histone H3 by COMPASS requires ubiquitination of histone H2B by Rad6./ Biol. Chem. 277(32), 28368-28371. 

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