1PT4

Solution structure of the Moebius cyclotide kalata B2

SOLUTION NMR

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NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D TOCSY	2mM kalata B2 in 0.5ml	70% H2O, 20% CH3CN, 10% D2O	0	4	ambient	298
2	2D NOESY	2mM kalata B2 in 0.5ml	70% H2O, 20% CH3CN, 10% D2O	0	4	ambient	298
3	DQF-COSY	2mM kalata B2 in 0.5ml	70% H2O, 20% CH3CN, 10% D2O	0	4	ambient	298
4	2D TOCSY	2mM kalata B2 in 0.5ml	80% D2O, 20% CH3CN	0	4	ambient	298
5	2D NOESY	2mM kalata B2 in 0.5ml	80% D2O, 20% CH3CN	0	4	ambient	298
6	2D TOCSY	2mM kalata B2 in 0.5ml	70% H2O, 20% CH3CN, 10% D2O	0	4	ambient	290

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	ARX	500
2	Bruker	DMX	750

NMR Refinement
Method	Details	Software
Simulated annealing using both torsion angle and Cartesian dynamics.	Structure was calculated using torsion angle dynamics within CNS and subsequently refined and energy minimised in a water shell using Cartesian dynamics in CNS according to protocols by Linge and Nilges (ARIA).	XwinNMR

NMR Ensemble Information
Conformer Selection Criteria	structures with the lowest energy
Conformers Calculated Total Number	50
Conformers Submitted Total Number	20
Representative Model	1 (lowest energy)

Additional NMR Experimental Information
Details	This structure was determined using standard 2D homonuclear techniques.

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	collection	XwinNMR	2.6	Bruker
2	data analysis	XEASY	1.3.7	Eccles, C., Guntert, P., Billeter, M. and Wuthrich, K.
3	structure solution	DYANA	1.5	Guntert, P., Mumenthaler, C. and Wuthrich, K.
4	refinement	CNS	1.0