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21 a.a.
30 a.a.
_NA
Key reference
DOI no: 10.1016/S0006-3495(92)81697-1 Biophys J 63:1210-1220 (1992) PubMed id: 1477273
Conformational changes in cubic insulin crystals in the pH range 7-11. O.Gursky, J.Badger, Y.Li, D.L.Caspar. ABSTRACT
To determine the effect of variations in the charge distribution on the conformation of a protein molecule, we have solved the structures of bovine cubic insulin over a pH range from 7 to 11 in 0.1 M and 1 M sodium salt solutions. The x-ray data were collected beyond 2-A resolution and the R factors for the refined models ranged from 0.16 to 0.20. Whereas the positions of most protein and well-ordered solvent atoms are conserved, about 30% of residues alter their predominant conformation as the pH is changed. Conformational switching of A5 Gln and B10 His correlates with the pH dependence of monovalent cation binding to insulin in cubic crystals. Shifts in the relative positions of the A chain NH2-terminal and B chain COOH-terminal groups are probably due to titration of the A1 alpha-amino group. Two alternative positions of B25 Phe and A21 Asn observed in cubic insulin at pH 11 are similar to those found in two independent molecules of the 2Zn insulin dimer at pH 6.4. The conformational changes of the insulin amino acids appear to be only loosely coupled at distant protein sites. Shifts in the equilibrium between distinct conformational substates as the charge distribution on the protein is altered are analogous to the electrostatically triggered movements that occur in many functional protein reactions.
Literature references that cite this PDB file's key reference
PubMed id Reference
19698094 C.Fufezan, and M.Specht (2009).
p3d--Python module for structural bioinformatics.BMC Bioinformatics, 10, 258.
14501114 B.V.Prasad, and K.Suguna (2003).
Effect of pH on the structure of rhizopuspepsin.Acta Crystallogr D Biol Crystallogr, 59, 1755-1761.
PDB codes: 1uh7 1uh8 1uh9
12657786 J.Diao (2003).
Crystallographic titration of cubic insulin crystals: pH affects GluB13 switching and sulfate binding.Acta Crystallogr D Biol Crystallogr, 59, 670-676.
PDB codes: 1b17 1b18 1b19 1b2a 1b2b 1b2c 1b2d 1b2e 1b2f 1b2g
11856829 R.Berisio, F.Sica, V.S.Lamzin, K.S.Wilson, A.Zagari, and L.Mazzarella (2002).
Atomic resolution structures of ribonuclease A at six pH values.Acta Crystallogr D Biol Crystallogr, 58, 441-450.
PDB codes: 1kf2 1kf3 1kf4 1kf5 1kf7 1kf8
10500144 J.J.Havranek, and P.B.Harbury (1999).
Tanford-Kirkwood electrostatics for protein modeling.Proc Natl Acad Sci U S A, 96, 11145-11150.
9449362 B.Yu, and D.L.Caspar (1998).
Structure of cubic insulin crystals in glucose solutions.Biophys J, 74, 616-622.
8842243 C.M.Yip, and M.D.Ward (1996).
Atomic force microscopy of insulin single crystals: direct visualization of molecules and crystal growth.Biophys J, 71, 1071-1078.
8161680 J.Badger, A.Kapulsky, O.Gursky, B.Bhyravbhatla, and D.L.Caspar (1994).
Structure and selectivity of a monovalent cation binding site in cubic insulin crystals.Biophys J, 66, 286-292.
8108391 J.Badger, Y.Li, and D.L.Caspar (1994).
Thallium counterion distribution in cubic insulin crystals determined from anomalous x-ray diffraction data.Proc Natl Acad Sci U S A, 91, 1224-1228.
7809046 O.Gursky, E.Fontano, B.Bhyravbhatla, and D.L.Caspar (1994).
Stereospecific dihaloalkane binding in a pH-sensitive cavity in cubic insulin crystals.Proc Natl Acad Sci U S A, 91, 12388-12392.
8274653 J.Badger (1993).
Multiple hydration layers in cubic insulin crystals.Biophys J, 65, 1656-1659. The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB codes are shown on the right.
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