1.8.3.3	C124A	reduced activity compared to wild type enzyme	
1.8.3.3	C15A	reduced activity compared to wild type enzyme	
1.8.3.3	C15A/C124A	reduced activity compared to wild type enzyme	
1.8.3.3	C15A/C74A/C85A/C124A	reduced activity compared to wild type enzyme	
1.8.3.3	C74A/C85A	reduced activity compared to wild type enzyme