Ligands citation sequence

It is often inconvenient to represent all the ligand formulae in detail. Abbreviations are often used and are indeed encouraged, with certain provisos. These are the abbreviations should all be written in lower case (with minor exceptions, such as Me, Et and Ph) and preferably not more than four letters with certain exceptions of wide currency, abbreviations should be defined in a text when they first appear in a formula, the abbreviation should be enclosed in parentheses, and its place in the citation sequence should be determined by its formula, as discussed above and particular attention should be paid to the loss of hydrous from a ligand precursor. 

Figure 4.10. PDB file (partial) for 3D structure of hen s egg-white lysozyme (ILYZ.pdb). The abbreviated file shows partial atomic coordinates for residues 34-36. Informational lines such as AUTHOR (contributing authors of the 3D structure), REVDAT, JRNL (primary bibliographic citation), REMARK (other references, corrections, refinements, resolution and missing residues in the structure), SEQRES (amino acid sequence), FTNOTE (list of possible hydrogen bonds), HELIX (initial and final residues of a-helices), SHEET (initial and final residues of / -sheets), TURN (initial and final residues of turns, types of turns), and SSBOND (disulfide linkages) are deleted here for brevity. Atomic coordinates for amino acid residues are listed sequentially on ATOM lines. The following HETATM lines list atomic coordinates of water and/or ligand molecules.

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