Table 1.

Enzyme–substrate binding report for adenine and kinetin binding to the APRT.

Ligand	Receptor	Interaction	Distance	E (kcal/mol)
Adenine interactions to human APRT
N7 3	OE1 GLU 104 (B)	H-donor	2.69	− 6.3
N6 6	O VAL 25 (B)	H-donor	3.12	− 1.9
N6 6	OE1 GLU 104 (B)	H-donor	2.86	− 5.1
N9 1	NH2 ARG 67 (B)	H-acceptor	3.77	− 0.8
N6 6	O HOH 332 (B)	H-acceptor	3.61	− 1.2
N1 7	CA PHE 26 (B)	H-acceptor	3.43	− 0.5
N1 7	N ARG 27 (B)	H-acceptor	2.98	− 4.4
N3 9	NH1 ARG 67 (B)	H-acceptor	3.02	− 7.6
N3 9	NH2 ARG 67 (B)	H-acceptor	3.52	− 1.2
6-ring	CD1 LEU 129 (B)	pi-H	3.69	− 0.5
5-ring	CD2 LEU 129 (B)	pi-H	3.94	− 1.2
Kinetin interactions to human APRT
C 1	CD1 LEU 159 (B)	H-donor	3.52	− 0.7
C 3	CD2 LEU 129 (B)	H-donor	3.04	− 0.6
C 5	OE2 GLU 104 (B)	H-donor	3.04	− 2.1
N 7	CE2 PHE 26 (B)	H-donor	3.71	− 0.5
N 13	CG1 VAL 24 (B)	H-donor	3.42	− 0.9
N 13	O VAL 25 (B)	H-donor	2.85	− 11.7
N 16	O4 PRP 201 (B)	H-donor	2.85	− 7.8
C 19	O5 PRP 201 (B)	H-donor	2.83	− 2.0
N 22	OE2 GLU 104 (B)	H-donor	2.65	− 3.9
N 25	CG1 VAL 24 (B)	H-donor	3.44	− 0.7
N 25	O VAL 25 (B)	H-donor	2.82	− 5.1
N 25	OE1 GLU 104 (B)	H-donor	2.61	− 7.2
N 25	OE2 GLU 104 (B)	H-donor	2.69	− 5.0
C 28	CD1 LEU 162 (B)	H-donor	4.14	− 0.5
C 28	O HOH 310 (B)	H-donor	3.30	− 0.6
C 1	CD1 LEU 159 (B)	H-acceptor	3.52	− 0.7
C 3	CD2 LEU 129 (B)	H-acceptor	3.68	− 0.6
N 7	CE2 PHE 26 (B)	H-acceptor	3.71	− 0.5
N 13	CG1 VAL 24 (B)	H-acceptor	3.42	− 0.9
N 25	CG1 VAL 24 (B)	H-acceptor	3.44	− 0.7
C 28	CD1 LEU 162 (B)	H-acceptor	4.14	− 0.5
N 13	OE2 GLU 104 (B)	Ionic	3.29	− 2.8
N 16	OE2 GLU 104 (B)	Ionic	3.82	− 0.9
N 22	OE1 GLU 104 (B)	Ionic	2.60	− 7.8
N 22	OE2 GLU 104 (B)	Ionic	2.65	− 7.3
N 22	O1P PRP 201 (B)	Ionic	3.68	− 1.3
N 25	OE1 GLU 104 (B)	Ionic	2.61	− 7.7
N 25	OE2 GLU 104 (B)	Ionic	2.69	− 6.9
N 16	6-ring TYR 105 (B)	Cation-pi	3.84	− 0.9