.....The germ-line lambda 3 immunoglobulin light-chain proteins have been correlated with the AL condition. Two mutants have been derived from this germ-line, the single mutant C34Y (3rC) and the triple mutant C34Y, W35A and P7D (3rCWP), presenting a remarkable difference in amyloid fibril formation propensities in vitro. Here we report the 1H, 13C and 15N resonance assignments of these proteins, as the first step to use solution nuclear magnetic resonance spectroscopy to get a better understanding of the amyloid fibril formation differences between these two mutants.