Table 2.

Difference in the deepening of the steroid nucleus of cardiotonic steroids between α1S- Na,K-ATPase and α1R-Na,K-ATPase. The distance was measured from C23 of the ligand docked to α1S- Na,K-ATPase (4HYT) to the C23 of the ligand docked to α1R- Na,K-ATPase (4HYT).

	OBN	DGX	MBG
α1S-NKA (4HYT) -α1R-NKA (4HYT)	9.173 Å	7.624 Å	7.446 Å
α1S-NKA (4RET)- α1R-NKA (4RET)	8.719 Å	8.994 Å	2.015 Å

Å—Angstrom; α1S-NKA—α1-subunit of a porcine Na,K-ATPase; α1R-NKA—α1-subunit of a rat Na,K-ATPase; OBN—ouabain; DGX—digoxin; MBG—marinobufagenin.