Leukocyte zinc protein Leukocytes, human

XI. The Zinc-Containing Protein from Human Leukocytes. 339... 

Preliminary experiments suggested that appreciable amounts of zinc in leukocytes are firmly bound to proteins, since only a very small fraction of the metal was found dialyzable. White cells from human subjects were frozen, thawed, diluted with distilled water, and then extracted with ether to remove lipids. The total white cells contained 13,000 uS-, the materials extracted by ether contained 39 /xg. of zinc, or 0.13% of the total zinc present. Investigations, therefore, centered on the zinc presumably bound to lipid-free protein. 

Since at the time at which this work was undertaken carbonic anhydrase was the only known zinc metalloenzyme (Keilin and Mann, 1940a), and no carbonic anhydrase activity could be detected in leukocytes (Van Goor, 1948), the work on the purification of the zinc-containing protein of leukocytes (Hoch and Vallee, 1952, 1953) was undertaken to elucidate the physiological and biochemical significance of zinc in human leukocytes through a study of its association with other components of these cells. 

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