enzyme analysis nonhuman 92 article 90 enzyme activity 62 priority journal 60 controlled study 52 unclassified drug 46 Animals 44 enzyme purification 32 Trypanosoma cruzi 28 Kinetics 26 animal tissue 24 Trypanosoma 20 animal experiment 20 protein expression 20 enzyme substrate 18 Humans 16 Substrate Specificity 16 Support, Non-U.S. Gov't 16 human 16 male 16 Animal 14 animal cell 14 enzyme inhibition 14 Amino Acid Sequence 12 Enzyme Activation 12 Molecular Sequence Data 12 amino acid sequence 12 in vivo study 12 nucleotide sequence 12