1DXZ

M2 TRANSMEMBRANE SEGMENT OF ALPHA-SUBUNIT OF NICOTINIC ACETYLCHOLINE RECEPTOR FROM TORPEDO CALIFORNICA, NMR, 20 STRUCTURES

SOLUTION NMR

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	DQF-COSY	CDCL3/CD3OH=1/1 WITH 0.1 M LICLO4		0.1 M LICLO4	4.0	1 atm	303
2	TOCSY	CDCL3/CD3OH=1/1 WITH 0.1 M LICLO4		0.1 M LICLO4	4.0	1 atm	303
3	NOESY	CDCL3/CD3OH=1/1 WITH 0.1 M LICLO4		0.1 M LICLO4	4.0	1 atm	303

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Varian	UNITY	600

NMR Refinement
Method	Details	Software
distance geometry	REFINEMENT DETAILS CAN BE FOUND IN THE JRNL CITATION ABOVE. THE NMR STUDY HAS BEEN CONDUCTED USING THE SYNTHETIC PEPTIDE WITH METHIONINE 243 REPLACED BY NORLEUCINE. SUCH AN ISOSTERIC REPLACEMENT USUALLY DOES NOT AFFECT THE PEPTIDE CONFORMATION, WHILE SYMPLIFYING THE SYNTHESIS. TO AVOID DIFFICULTIES WHICH MAY ARISE FROM THE PRESENCE OF A NONSTANDARD AMINO ACID RESIDUE AS WELL AS FOR THE PURPOSE OF AGREEMENT BETWEEN THE NATIVE M2 FRAGMENT AND THE CONFORMERS TO BE DEPOSITED, THE NORLEUCINE RESIDUE WAS REPLACED BY METHIONINE.	FANTOM

NMR Ensemble Information
Conformer Selection Criteria	LEAST RESTRAINTS VIOLATION
Conformers Calculated Total Number	300
Conformers Submitted Total Number	20
Representative Model	4 (n/a)

Additional NMR Experimental Information
Details	THE STRUCTURE WAS DETERMINED USING 2D-1H-NMR SPECTROSCOPY IN THE MEDIUM WHICH SHOULD BE ADEQUATE FOR THE M2 SEGMENT WITH ITS NON-LIPID SURROUNDING IN THE INTACT NICOTINIC ACTYLCHOLINE RECEPTOR. THE PH GIVEN IN THE EXPERIMENTAL DETAILS IS AN APPROXIMATION ONLY FOR THE MIXTURE OF ORGANIC SOLVENTS USED.

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	refinement	FANTOM	4.0	R.FRACZKIEWICZ,C.MUMENTHALER,B. VON FREYBERG, T.SCHAUMANN,W.BRAUN
2	structure solution	VARIAN VNMR	VNMR
3	structure solution	XEASY
4	structure solution	DYANA
5	structure solution	MARDIGRAS

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.