APPLICATION OF NONLINEAR SAMPLING SCHEMES TO COSY-TYPE SPECTRA

Nonlinear sampling along the t1 dimension is applied to COSY-type spec tra. The sine dependence of the time domain signals for the cross peak s is matched by a nonlinear sampling scheme that samples most densely around the maximum of the sine function. Data are processed by maximum entropy reconstruction, using a modified implementation of the 'Cambr idge' algorithm of Skilling and Bryan. The procedure is demonstrated f or P.E.COSY spectra recorded on a cyclic hexapeptide and on a 126-resi due domain of the protein villin. The number of t1 values in the nonli nearly sampled experiments was reduced by a factor of four compared to linear sampling. The sensitivity and resolution of the resulting spec tra are comparable to those achieved by conventional methods. The meth od described can thus significantly reduce the measuring time for COSY -type spectra.