R2R1_TM

The program r2r1_tm calculates a local effective correlation time from the R2/R1 ratio, in which R2 and R1 are the spin-spin and spin-lattice relaxation rate constants for nitrogen-15 or carbon-13 spins. The local correlation times are used as input for the quadric_diffusion program.

Usage: r2r1_tm [-1] > tm_file

The program prompts for the following information:

nucleus_type (15N or 13C)
proton_spectrometer_field (MHz)
initial_tm_estimate (ns)
number_of_entries (in the r2r1_file)
r2r1_file_name

The input r2r1_file contains one line for each residue to be analyzed. Each line contains the following fields:

residue_number r2/r1_ratio r2/r1_uncertainty

The input residue numbers should correspond to residue numbers in a pdb file for the molecule. Lines beginning with "#" are ignored in the r2r1_file. If the -1 flag is included on the command line, then the input r2r1_file is not read and the user is prompted to enter a single r2/r1_ratio and uncertainty. The functionality with the -1 flag is essentially the same as using the 'tmest' program of earlier releases.

The output tm_file contains one line for each residue analyzed. Each line contains the following fields:

residue_number tm tm_uncertainty