They Use Enzymes for Everything!(Aacc 50TH Anniversary Retrospective‪)‬

This year marks the 50th anniversary of the American Association for Clinical Chemistry. In tribute to this semicentenary, this journal will reflect on its published achievements over the past five decades. [1] Our Editor has recently enumerated some of the publications that have had an impact on the field, as demonstrated by a solid history of citation (1). This editorial, the first in a projected series of four to appear this year, will reflect on those papers that have advanced the area of enzymes and protein markers-now a regular feature in these pages. Of the papers that have achieved citation fame (1), approximately 20% deal with clinical enzymology (2-7). Yet another 20% focus on the use of enzymes as analytical tools, e.g., those listed in references 8-10. In the first volume of this journal (1954), enzyme measurements as markers of human disease were the focal points of only two papers. The topics were amylase and arginase. None characterized the use of enzymes as analytical reagents, reflecting clinical laboratory practice of the day. Today, in most laboratories, of the two dozen "routine" chemistry analytes, nearly two-thirds are often determined by enzymatic analyses. This is largely the result of the explosion in the number of studies of enzymes as catalysts, markers of disease, and tools for the laboratorian over the 1960s and the subsequent two decades. This growth phase in enzymology was concurrent with the growth of the practice of clinical chemistry and of the AACC. Without these advances, modern clinical laboratory analyses would not be possible. The detection of proteins in serum by their catalytic activity as a reporter of tissue damage is a cornerstone of medical laboratory analyses. The uses of a wide variety of enzymes from a still wider variety of sources are now firmly entrenched in the arsenal of the laboratorian. The breadth of analysis, from a humble but often critical glucose measurement to the large number of enzymes used in molecular biology, is astonishing. If I may be allowed a degree of nostalgia, this author, who (within acceptable round-off error) completes his 5th decade concurrently with the Association, recalls an analytical chemistry professor chiding him as an undergraduate for considering a career in clinical chemistry or biochemistry. "That's not real chemistry", he asserted, with an almost Nixonian emphasis on the word r "they use enzymes for everything!". His disdain failed to dissuade me, but his words-unlike most else from that era, these were, after all, the 1960s-are often recalled with an appropriate sense of irony.