Combine information from the following scientific abstract:

"We chose crambin, a hydrophobic and water-insoluble protein originally isolated from the seeds of the plant Crambe abyssinica, as a model for NMR investigations of membrane-associated proteins. We produced isotopically labeled crambin(P22,L25) (variant of crambin containing Pro22 and Leu25) as a cleavable fusion with staphylococcal nuclease and refolded the protein by an approach that has proved successful for the production of proteins with multiple disulfide bonds. We used NMR spectroscopy to determine the three-dimensional structure of the protein in two membrane-mimetic environments: in a mixed aqueous-organic solvent (75%/25%, acetone/water) and in DPC micelles. With the sample in the mixed solvent, it was possible to determine (>NH...OC<) hydrogen bonds directly by the detection of (h3)J(NC)' couplings. H-bonds determined in this manner were utilized in the refinement of the NMR-derived protein structures. With the protein in DPC (dodecylphosphocholine) micelles, we used manganous ion as an aqueous paramagnetic probe to determine the surface of crambin that is shielded by the detergent. With the exception of the aqueous solvent exposed loop containing residues 20 and 21, the protein surface was protected by DPC. This suggests that the protein may be similarly embedded in physiological membranes. The strategy described here for the expression and structure determination of crambin should be applicable to structural and functional studies of membrane active toxins and small membrane proteins."

To this summary:

The title of this entry is "Solution structure of crambin in acetone/water mixed solvent" and the experimental method used is Solution NMR. This entry contains one protein molecule, crambin from Crambe hispanica subsp. abyssinica, which is distributed in one chain, Chain A. Chain A contains one entity, crambin from Crambe hispanica subsp. abyssinica. Crambin from Crambe hispanica subsp. abyssinica is a protein molecule.

You cannot add any extra information that is not originally included in the summary or the scientific abstract. You should only add information from the abstract to the summary so it's becomes more complete. Only paragraphs are allowed, no topics or list like information. Be concise. The word "production" should not appear in your response.
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