Structural Basis of the Tanford Transition of Bovine β-Lactoglobulin,

• DOI: 10.1021/bi981016t
• Publication Date: 2002-07-26T05:19:13Z
• Authors: Bin Y. Qin; Maria C. Bewley; Lawrence K. Creamer; Heather M. Baker; Edward N. Baker; Geoffrey B. Jameson
• Keywords: Residue (chemistry); Side chain

The structures of the trigonal crystal form bovine β-lactoglobulin variant A at pH 6.2, 7.1, and 8.2 have been determined by X-ray diffraction methods a resolution 2.56, 2.24, 2.49 Å, respectively. corresponding values for R (Rfree) are 0.192 (0.240), 0.234 (0.279), 0.232 (0.277). C N termini as well two disulfide bonds clearly defined in these models. glutamate side chain residue 89 is buried 6.2 becomes exposed 7.1 8.2. This conformational change, involving loop 85−90, provides structural basis variety pH-dependent chemical, physical, spectroscopic phenomena, collectively known Tanford transition.