26288
A crystal structure suggests four water molecules are present in the binding cavity of thapsigargin in sarco / endoplasmic reticulum calcium ATPase ( SERCA ) .
 Chemical: thapsigargin; Chemical: calcium
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: thapsigargin; Chemical: calcium