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PDBsum entry 1b2e

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Hormone/growth factor PDB id
1b2e
Contents
Protein chains
21 a.a. *
30 a.a. *
Ligands
SO4
Waters ×56
* Residue conservation analysis

References listed in PDB file
Key reference
Title Crystallographic titration of cubic insulin crystals: ph affects glub13 switching and sulfate binding.
Author J.Diao.
Ref. Acta Crystallogr D Biol Crystallogr, 2003, 59, 670-676. [DOI no: 10.1107/S0907444903002208]
PubMed id 12657786
Abstract
Structures of porcine insulin crystals soaked in 1 M sodium sulfate at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00 have been determined at between 1.7 and 1.9 A resolution. GluB13 exhibits a single conformation at pH </= 5.80, two conformations between pH 6.00 and 6.98 and a single conformation at pH 9.00. Between pH 6.00 and 6.98, the conformation of GluB13 switches from one rotamer to another rotamer. Between pH 6.16 and 6.26, PheB1 undergoes a significant conformational change. By pH 9.00 many residues have undergone relatively large shifts and HisB10 exhibits a double conformation. As a result of the pH increase, the occupancy of the sulfate ion decreases from a maximum of 1.00 at pH 5.00 to a minimum of 0.46 at pH 6.50. Comparison of the structures, the observed and calculated structure factors and map correlation coefficients indicate that the porcine insulin structure changes gradually as a function of pH.
Figure 2.
Figure 2 Structures at ten different pH and corresponding 2F[o] - F[c] maps. Structures in the region of GluB13 and the sulfate ion are presented and 2F[o] - F[c] maps are contoured at the 0.8 level because of the approximate half-occupancy of the two rotamers of GluB13 and the lower electron density compared with the rest of the structure. Sub-figures correspond to the structures at pH 5.00, 5.53, 5.80, 6.00, 6.16, 6.26, 6.35, 6.50, 6.98 and 9.00, respectively.
Figure 4.
Figure 4 Sulfate-binding region. The coordinates at pH 5.00 were used to produce the figure.
The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2003, 59, 670-676) copyright 2003.
Secondary reference #1
Title Conformational changes in cubic insulin crystals in the ph range 7-11.
Authors O.Gursky, J.Badger, Y.Li, D.L.Caspar.
Ref. Biophys J, 1992, 63, 1210-1220.
PubMed id 1477273
Abstract
Secondary reference #2
Title Monovalent cation binding to cubic insulin crystals.
Authors O.Gursky, Y.Li, J.Badger, D.L.Caspar.
Ref. Biophys J, 1992, 61, 604-611.
PubMed id 1504238
Abstract
Secondary reference #3
Title Flexibility in crystalline insulins.
Author J.Badger.
Ref. Biophys J, 1992, 61, 816-819.
PubMed id 1504252
Abstract
Secondary reference #4
Title Structure of the pig insulin dimer in the cubic crystal.
Authors J.Badger, M.R.Harris, C.D.Reynolds, A.C.Evans, E.J.Dodson, G.G.Dodson, A.C.North.
Ref. Acta Crystallogr B, 1991, 47, 127-136.
PubMed id 2025410
Abstract
Secondary reference #5
Title Water structure in cubic insulin crystals.
Authors J.Badger, D.L.Caspar.
Ref. Proc Natl Acad Sci U S A, 1991, 88, 622-626. [DOI no: 10.1073/pnas.88.2.622]
PubMed id 1988957
Full text Abstract
Secondary reference #6
Title Zinc-Free cubic pig insulin: crystallization and structure determination.
Authors E.J.Dodson, G.G.Dodson, A.Lewitova, M.Sabesan.
Ref. J Mol Biol, 1978, 125, 387-396. [DOI no: 10.1016/0022-2836(78)90409-6]
PubMed id 731699
Full text Abstract
Figure 6.
FIG. 6. Average Sim-type weights (in y/,) against 4 sin2 B/AZ.
Figure 8.
FIG 8. Schematic diagram of the arrangement of insulin molecule in the 23,3 unit cell. It'or convenience, each oval represents a symmetrical insulin dimor.
The above figures are reproduced from the cited reference with permission from Elsevier
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