1.5.1.25	1-piperideine 2-carboxylate + NADPH + H+	-	
1.5.1.25	aminoethyl cysteine ketimine + NADPH + H+	-	
1.5.1.25	DELTA1-piperideine 2-carboxylate + NADPH + H+	-	
1.5.1.25	DELTA1-pyrrolidine 2-carboxylate + NADPH + H+	-	
1.5.1.25	DELTA2-thiazoline-2-carboxylate + NADPH + H+	-	
1.5.1.25	lanthionine ketimine + NADPH + H+	-	
1.5.1.25	additional information	the non-sulfur substrates exist in equilibrium with open chain forms at low acidic pH. At neutral pH, they exist predominantly as the enzymatically favorable cyclic ketimine form (in which the ring double bond is in the C=N form), while sulfur-containing cyclic ketimine substrates exist predominantly as the enzymatically unfavorable enamine form (in which the ring double bond is in the C=C form) at neutral pH	
1.5.1.25	additional information	the non-sulfur substrates exist in equilibrium with openchain forms at low acidic pH. At neutral pH, they exist predominantly as the enzymatically favorable cyclic ketimine form (in which the ring double bond is in the C=N form), while sulfur-containing cyclic ketimine substrates exist predominantly as the enzymatically unfavorable enamine form (in which the ring double bond is in the C=C form) at neutral pH	
1.5.1.25	additional information	reciprocal relationship between thyroid hormone binding and DELTA1-piperideine-2-carboxylate (P2C) binding to ketimine reductase	
1.5.1.25	S-(2-aminoethyl)-L-cysteine ketimine + NADPH + H+	-	
1.5.1.25	thiomorpholine 3-carboxylate + NAD(P)+	-