Question

In 1926, James Sumner concluded that urease was a protein based on the fact that crystals of the enzyme tested positive for reagents that reacted with proteins and negative for reagents that reacted with fats, carbohydrates, and other substances. His conclusion was attacked by other enzymologists, who found that their highly active enzyme solutions failed to contain evidence of protein. How can these seemingly opposing findings be reconciled?

Answer 1

James Sumner concluded urease was a protein as it formed crystals and tested positive with protein-specific reagents.

Step-by-step explanation:

In 1926, James Sumner concluded that urease was a protein because it crystallized like other known proteins and reacted positively with reagents specific to proteins.

The opposition from other enzymologists, who failed to find protein evidence in their enzyme solutions, likely stemmed from the nascent understanding of enzymes at the time, which were thought not to conform to typical chemical behaviors.

Sumner's methodology might have differed from his contemporaries, perhaps by using different purification techniques that enabled the crystallization, which might not have been replicable by others using less refined methods.

Enzymes are remarkable for their substrate specificity and the incredible rate enhancements they offer for biological reactions. Sumner's discovery was initially ridiculed but was later validated, earning him a Nobel Prize in Chemistry in 1946.

The seemingly opposing findings he and other enzymologists had are reconcilable by understanding that enzyme preparations can vary widely, and that over time, methods and conceptions about enzymatic proteins have evolved significantly.

His conclusion was initially disputed by others unable to replicate his findings, possibly due to different experimentation methods. Over time, Sumner's findings were validated, illustrating that conceptions and methods relating to enzymes have evolved, leading to his Nobel Prize award.