28662
The development of an array of fluorescent amino acids with a variety of properties , such as environment sensitivity , chelation - enhanced fluorescence , and profluorescence , has allowed researchers to gain insights into biological processes , including protein conformational changes , binding events , enzyme activities , and protein trafficking and localization .
 amino acids
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 amino acids