The phrase "a key enzyme that" is correct and usable in written English.
It can be used when discussing the importance or role of a specific enzyme in a biological or biochemical context.
Example: "The study focused on a key enzyme that regulates metabolic pathways in the cell."
Alternatives: "an essential enzyme that" or "a crucial enzyme that".
Malate dehydrogenase (MD) is a key enzyme that plays an important role in energy metabolism.
In both situations, a key enzyme that moves copper in and out of cells is mutated, causing misregulation and copper overload – often to toxic levels – in the liver.
L-asparaginase is a key enzyme that degrades asparagine and this aspect of the enzyme has found a dominant role in chemotherapeutic and food processing industry.
Last September, scientists reported the structure of a key enzyme that allows HIV to replicate, making it an obvious target for drugs.
More precisely, 18F-FLT is entrapped in cells during the S-phase and its uptake correlates with the activity of thymidine kinase-1 (TK-1), a key enzyme that is up-regulated during DNA synthesis and cellular growth [65, 66].
The bulk of this year's prize haul--$620,000--goes to a project led by Jan Balzarini and Eric de Clercq of the Rega Institute in Leuven, Belgium, for their discovery of new inhibitors of reverse transcriptase, a key enzyme that helps HIV invade human DNA.
As Rosie Mestel explained in the Los Angeles Times, the genes that make this possible are spliced into the plants from sources like Bt (a soil bacterium that makes proteins that kill flies, moths and other insects) and Agrobacterium (another soil bacterium that allows plants to make a key enzyme that can withstand the pesticide Roundup).
DGAT1 is a key enzyme that catalyzes the final step in triglyceride synthesis.
Gsk3β is a key enzyme that phosphorylates β-catenin at NH2-terminal serine threonine residues.
GalDH is a key enzyme that determines whether a plant can synthesize AsA via the L-galactose pathway [5].
FASN is a key enzyme that synthesizes long-chain fatty acids from acetyl-CoA and malonyl-CoA and is essential for embryonic development.
