When pioneers of winemaking like Louis Pasteur or André Tchelistcheff are mentioned, James B. Sumner is often overlooked. Nonetheless, this Nobel-prize-winning chemist (1946) set in motion the entire scientific field for today’s article. In 1926, Sumner successfully crystallized the enzyme urease and performed chemical analysis that demonstrated that urease is a protein. Not at all shocking today, the results were revolutionary at the time. The existence and activity of enzymes had been previously observed, but their exact nature and modes of action had not been discovered. Thanks to Sumner (and subsequent researchers), we know that all enzymes are proteins and they act as biological catalysts. They act on specific substrate molecules where they execute a range of repeated chemical reactions, not being destroyed themselves in the process. They are critical to life processes, facilitating reactions that otherwise might not take place at all and accelerating others that would be too slow. Naturally occurring (endogenous) enzymes have always played key roles in fermentation and development of wine. The naming of enzymes, with the characteristic ending –ase, will usually give a clue
Technique