Moses Kunitz

Academic career Kunitz' position at Rockefeller was originally secured by Jacques Loeb. After Loeb died in 1924, John H. Northrop succeeded him and retained Kunitz' position; the two would collaborate extensively on experiments involving protein crystallization for much of their remaining careers. Both Northrop and Kunitz moved to Rockefeller's Princeton, New Jersey campus in 1926; Kunitz returned to New York City in 1952. He then assumed professor emeritus status but continued to work regularly in the laboratory until eventually retiring in 1970.

Research Kunitz is best known for his efforts in protein crystallization, successfully crystallizing a number of enzymes and enzyme precursor proteins, particularly proteases. Kunitz worked with trypsin and chymotrypsin and their precursors, as well as pepsin. He also studied protease inhibitors and devoted particular effort to the soybean trypsin inhibitor; the inhibitor protein, its domain family, and a soybean cultivar lacking this protein are all named after him. For their role in isolating, purifying, and crystallizing enzymes - a subject underscored by Kunitz' work with Northrop - John H. Northrop, Wendell M. Stanley, and James B. Sumner were awarded the Nobel Prize in Chemistry in 1946. Kunitz himself was nominated three times for a share of a Nobel for this work.

In addition to his work on crystallization of proteases, Kunitz also performed careful work in enzymology, characterizing the kinetics and thermodynamics of protease reactions. He worked on other proteins as well, in particular ribonucleases, which were popular model systems for their small size and ease of crystallization. During World War II he worked on government-assigned crystallization projects and was noted for the facility with which he crystallized hexokinase.