Experiment metadata

Global metadata table

key	description
ARTICLE_DOI	DOI of the of the original publication of the experimental data
DATA_DOI	DOI of the dataset deposition with raw NMR data
DATA_REF	Reference to deposited dataset
TEMPERATURE	Temperature (K) of the experiment
MEMBRANE_COMPOSITION	Dictionary of molar fractions of membrane phase
SOLUTION_COMPOSITION	Dictionary of ion concentrations in the system
ADDITIONAL_MOLECULES	Dictionary of molecules which are not in the databank
TOTAL_HYDRATION	Total hydration of the system (water mass %)
PH	pH of the system
PH_METHOD	Method of pH setting or measurement (buffer / measurement)
REAGENT_SOURCES	Description of lipid reagents. Source, purity, etc.
SAMPLE_PROTOCOL	Protocol for sample preparation (in free format, references are welcome).

NMR specific metadata

key	description
T_RF_HEATING	Correction of the temperature according to RF heating
INSTRUMENT	Instrument name (including field)
METHOD	Method of OP measurement “abbr1:abbr2” (see detailed explaining below)
SIGN_MEASURED	NONE or S-DROSS
DETAILS	Description of NMR experiment type

X-ray specific metadata

key	description
SOURCE	Source name
LAMBDA	Source wavelength or range
QRANGE	Scattering detection range (Q-range)
DETECTOR	Detector type
DISTANCE	Distance to detector (m)
DATATYPE	Data type (batch or SEC)
EXPOSURE	Exposure time per frame (s)
FRAMES	Number of frames
SAMPLE_TYPE	‘MLV’, ‘SUV’, ‘GUV’, ‘OS’ (oriented sample), ‘BIC’

General fields

1. ARTICLE_DOI
   DOI of the original publication where the experimental data originates.

2. DATA_DOI
   DOI of the dataset deposition with raw NMR data (e.g., nmrXive).

3. DATA_REF If the dataset doesn’t have DOI, we engage to add some persistent identifier or even URL if the first doesn’t exist.

4. TEMPERATURE
   Temperature (K) of the experiment. For NMR experiment, if NMR:T_RF_HEATING is ‘unknown’ (or not given), the reported temperature from the probe is settet here. Otherwise, please insert RF-corrected temperature.

5. MEMBRANE_COMPOSITION
   Dictionary of molar fractions of bilayer components. For example:

MEMBRANE_COMPOSITION:
  POPC: 0.93
  CHOL: 0.07

All the molecules should be registered in the molecular inventory in the membrane subfolder.

6. SOLUTION_COMPOSITION
   Dictionary of solution composition of the system (mass %), main solvent is not listed:

SOLUTION_COMPOSITION:
  SOD: 0.5
  CLA: 0.24
  GLUCOSE: 0.1

All the molecules should be registered in the molecular inventory in the solution subfolder. Do not provide whole salts! Only separated ions. Remember that the counterions of charged lipids are also part of the solution.

7. ADDITIONAL_MOLECULES Dictionary of additional molecules in the format:

ADDITIONAL_MOLECULES:
    TFA: trifluoroacetic acid, 0.1%
    DMSO: dimethylsulfoxide, 0.1%
    DSS: sodium trimethylsilylpropanesulfonate, 0.01%
    EDTA: ethylenediaminetetraacetic acid, 0.1 mM

we can use INCHI-key, CAS number or just IUPAC name. If molecule is important for the composition, it should get the metadata inside the databank and be mentioned under SOLUTION_COMPOSITION instead.

8. TOTAL_HYDRATION
   Mass % of water in the sample. For NMR experiment, it is better if measured by ¹H MAS NMR.

9. PH
   pH of the system (number or UNKNOWN)

10. PH_METHOD
    How the pH value is got: measured by pH electrode or indicator paper, measured by NMR, set by buffer.

11. REAGENT_SOURCES
    Which reagents are used for lipids – should be specified for every lipid.

12. SAMPLE_PROTOCOL Protocol of liposome (or OS) preparation. A description of the preparation steps and conditions used to obtain the sample, such as lipid composition, hydration method, extrusion, alignment procedures, and any buffers used. For NMR sample, it is important to mention how the targeted hydration level is reached: lyophilised powder is hydrated, liposome suspension is dehydrated, or liposome suspension is ultracentrifugated to get lipid-rich phase.

NMR-specific fields

All the following fields are subfields of NMR: block.

1. INSTRUMENT
   Name of the instrument and field strength.

2. METHOD
   A field identifying the NMR method used (string formed as METHOD:SUBMETHOD, e.g., “2H:QE”).

   • Variants for METHOD: “2H”, “CDLF”, “PDLF”
     Two main methods are ²H-NMR and ¹H-¹³C SLF (separate local field) NMR experiments which can be either CDLF (Carbon-detected local field) or PDLF (Proton-DLF).

   • Sub-Method for “2H”: “SP” | “QE” | “see_comments”
     For ²H NMR, the submethod used is either “single pulse” or “quadrupolar echo”.

   • Sub-Method for “CDLF”: “REDOR” | “DIPSHIFT” | “recDIPSHIFT” | “see_comments”
     For CDLF method, the variants could be Rotational-Echo Double-Resonance (REDOR), Dipolar-Coupling chemical shift correlation (DIPSHIFT), or recoupled DIPSHIFT (recDIPSHIFT).

   • Sub-Method for “PDLF”: “DROSS” | “R18_1^7” (or other numbers characterizing R-type sequence) | “see_comments”
     For PDLF method, subvariants could use dipolar recoupling on-axis with scaling and shape preservation (DROSS), or R-type recoupling (recoupling using symmetry-based pulse sequences)

3. SIGN_MEASURED
   Method name (e.g. S-DROSS) if order parameter sign was measured, NONE otherwise.

4. T_RF_HEATING
   How RF heating is dealt (UNKNOWN / measured / guessed)

5. DETAILS
   Links to the pulse sequence, corresponding paper and precise parameters if important. Obligatory explanation if NMR:METHOD uses “see_comments” for SUBMETHOD.

Scattering-specific fields

All the following fields are subfields of XRAY: block.

1. SOURCE X-ray source description. Name of the core facilities or instrument name if laboratory source was used. Name of beamline and source if synchrotron data (e.g. EMBL P12, PETRA III).

2. LAMBDA Source wavelength or range. Wavelength (and/or range) of the X-ray beam used, with units (e.g., Ångstroms).

3. QRANGE Scattering detection range (Q-range). The accessible scattering vector range, typically given in 1/Å.

4. DETECTOR Detector type (e.g., CCD camera, PILATUS, or other detector model).

5. DISTANCE Distance to detector (m). The separation between the sample and the detector, in meters.

6. DATATYPE Measurement data type. Batch mode or size-exclusion chromatography (SEC) mode.

7. EXPOSURE Exposure time per frame. The total data acquisition time per measurement frame, usually given in seconds.

8. FRAMES Number of frames collected for dataset.

9. SAMPLE_TYPE ‘MLV’, ‘SUV’, ‘GUV’, ‘OS’ (oriented sample), ‘BIC’. The type of sample used, with definitions: MLV (multilamellar vesicles), SUV (small unilamellar vesicles), GUV (giant unilamellar vesicles), OS (oriented sample), BIC (bicelles).