3.4.23.40	2	7	-	
3.4.23.40	2.5	6	-	
3.4.23.40	3	-	about 40% of maximum activity	
3.4.23.40	3	5.5	the enzyme has more than 50% activity in a pH range of 3.0-5.5	
3.4.23.40	4	-	inactive above	
3.4.23.40	7	-	about 10% of maximum activity