Nickel inhibits binding of alpha2-macroglobulin-methylamine to the low-density lipoprotein receptor-related protein/alpha2-macroglobulin receptor but not the alpha2-macroglobulin signaling receptor.

A previous study demonstrated that activated alpha2-macroglobulin (alpha2M*) binding to the low-density receptor-related protein/alpha2-macroglobulin receptor (LRP/alpha2MR) is blocked by Ni2+ [Hussain, M. M., et al. (1995) Biochemistry 34, 16074-16081]. We now report that the effect of Ni2+ is on a region of the alpha2M molecule upstream of the carboxyl terminal receptor recognition domain. This observation is consistent with previous observations from this laboratory suggesting that alpha2M* binding to LRP/alpha2MR involves a region of the alpha2M molecule immediately upstream of the receptor recognition domain [Enghild, J. J., et al. (1989) Biochemistry 28, 1406-1412]. We further demonstrate that Ni2+ has no effect on the binding of alpha2M* or a cloned and expressed receptor binding fragment (RBF) to the recently described alpha2M signaling receptor as assessed by direct binding and signal transduction studies.

Duke Scholars

Author Uma Kant Misra  

Author Salvatore Vincent Pizzo