Alternate morpheeins of allosteric proteins as a target for the development of bioactive molecules

1. A method of inhibiting a multimeric porphobilinogen synthase from forming an active form, the method comprising: applying a composition comprising an inhibitor adapted to inhibit formation of an active form of a multimeric porphobilinogen synthase to the multimeric porphobilinogen synthase; associating the composition with the less active form of the multimeric porphobilinogen synthase; inhibiting the less active form from assembling into the active form and thereby inhibiting the multimeric porphobilinogen synthase from forming the active form.

2. A method of inhibiting a multimeric protein comprising an equilibrium of assembly states, each assembly having a plurality of units, wherein each of said units comprises a first complementary surface and a second complementary surface and wherein the first complementary surface of one unit is associated with the second complementary surface of another unit, provided that the assembly is at least one of different quaternary isoforms on condition that:

(1) one conformation of said units determines a first quaternary isoform but does not allow formation of other quaternary isoforms;

(2) a different conformation of said units determines one of a different quaternary isoforms, but does not allow formation of the first quaternary isoform;

(3) the different conformations of said units are in an equilibrium; and

(4) the conformation of said different quaternary isoforms influences a function of said multimeric protein,

the method comprising:

applying to the multimeric protein a composition comprising an inhibitor adapted to inhibit formation of an active form of the multimeric protein;

associating the composition with a less active form of the multimeric protein;

inhibiting the less active form from assembling into the active form and thereby inhibiting the multimeric protein from forming the active form,

wherein said multimeric protein is a member selected from the group consisting of porphobilinogen synthase, a Class Ia ribonucleotide reductase, Pseudomonas aeruginosa GDP- Mannose dehydrogenase, Bacillus subtilis HPr, mammalian CoA transferase, purine nucleoside phosphorylase, and peroxiredoxins.

3. The method of claim 2 , wherein the unit is a member selected from the group consisting of a monomer, a dimer, a trimer, a tetramer, a pentamer, a hexamer, a heptamer, an octamer, and a decamer.

4. The method of claim 2 , wherein said multimeric protein is porphobilinogen synthase comprising eight porphobilinogen synthase monomers.