He was the brother of Michael M. Kaback, pediatrician and human geneticist, who developed a screening program to detect and prevent Tay–Sachs disease, a rare and fatal genetic disorder most common in Ashkenazi Jews.
The system consisted of osmotically sealed membrane vesicles of defined orientation (right-side-out) that catalyze active transport essentially as well as intact cells, but lack subsequent metabolism of the solutes accumulated.
[5][6] With the emergence of molecular biology, he and his colleagues pioneered Cysteine-Scanning Mutagenesis in combination with chemical modification, as well as a battery of site-directed biophysical/biochemical techniques to demonstrate almost incontrovertibly that LacY functions by a mechanism involving alternating access of sugar- and proton-binding sites to either side of the membrane.
Without a crystal structure, Kaback and colleagues succeeded in using the approach to obtain essential information about helix packing, the organization of the sugar-binding site, and the residues involved in H+ translocation and coupling.
[8][9][10] He and his colleagues then obtained an X-ray crystal structure of LacY, an essential step towards understanding the molecular mechanism, which has had important impact on the field of membrane transport.