Zinc Metabolism in Normal, Lectin-stimulated and Leukemic Lymphocytes

Gel filtration of the cytoplasmic fraction of homogenate from human peripheral lymphocytes incubated with <ce:inf>65</ce:inf>Zn gave five separate peaks with molecular weights of > 150,000, 90,000, 65,000, 20 000, and < 1000 daltons. Peaks I–IV consisted of proteins. The low molecular weight (peak V) may consist of nucleotides, polyamines and amino acids. After gel filtration 75–80% of the ₆₅Zn activity was found in peak V. Lectin-induced stimulation of normal lymphocytes revealed a distribution pattern of ₆₅Zn binding similar to that of unstimulated cells. There was only a slightly enhanced incorporation into the protein peaks I–IV. When peripheral lymphocytes of B lymphocyte origin from patients with chronic lymphocytic leukemia were incubated with ₆₅Zn the same peaks were seen as with supernatants obtained from normal lymphocytes. Lectin-induced stimulation of leukemic lymphocytes had no significant effect on the ₆₅Zn distribution pattern.