1.1.2.7	ammonia	ammonia affects the rate-limiting step of breaking of the methyl C-H bond	
1.1.2.7	methylamine	can replace NH4+	
1.1.2.7	NH4+	absolute requirement, NH4+ can be replaced by methylamine but not by di- or triamines	
1.1.2.7	NH4Cl	essential activator