4.3.1.19	dithiothreitol, allothreonine and pyridoxal phosphate are all required to maintain a stable form of threonine dehydratase	
4.3.1.19	L-Ile protects the enzyme against inactivation at low temperatures	
4.3.1.19	loss of activity of dehydratase I at 37 C is prevented by 1 mM Ile, but that of dehydratase II is not