4E3T:
reference: Diminishing returns and tradeoffs constrain the laboratory optimization of an enzyme., Tokuriki N, Jackson CJ, Afriat-Jurnou L, Wyganowski KT, Tang R, Tawfik DS, Nat Commun. 2012 Dec 4;3:1257. doi: 10.1038/ncomms2246. PMID: 23212386

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