2BLG

STRUCTURAL BASIS OF THE TANFORD TRANSITION OF BOVINE BETA-LACTOGLOBULIN FROM CRYSTAL STRUCTURES AT THREE PH VALUES; PH 8.2

Summary for 2BLG

• Entry DOI: 10.2210/pdb2blg/pdb
• Descriptor: BETA-LACTOGLOBULIN (2 entities in total)
• Functional Keywords: transport, beta-lactoglobulin, ph-dependent conformation, loop movement, tanford transition
• Biological source: Bos taurus (cattle)
• Cellular location: Secreted: P02754
• Total number of polymer chains: 1
• Total formula weight: 18387.26

Authors

Qin, B.Y.,Bewley, M.C.,Creamer, L.K.,Baker, H.M.,Baker, E.N.,Jameson, G.B. (deposition date: 1998-08-29, release date: 1999-01-27, Last modification date: 2024-10-30)

Primary citation

Qin, B.Y.,Bewley, M.C.,Creamer, L.K.,Baker, H.M.,Baker, E.N.,Jameson, G.B.
Structural basis of the Tanford transition of bovine beta-lactoglobulin.
Biochemistry, 37:14014-14023, 1998

PubMed Abstract: The structures of the trigonal crystal form of bovine beta-lactoglobulin variant A at pH 6.2, 7.1, and 8.2 have been determined by X-ray diffraction methods at a resolution of 2.56, 2. 24, and 2.49 A, respectively. The corresponding values for R (Rfree) are 0.192 (0.240), 0.234 (0.279), and 0.232 (0.277). The C and N termini as well as two disulfide bonds are clearly defined in these models. The glutamate side chain of residue 89 is buried at pH 6.2 and becomes exposed at pH 7.1 and 8.2. This conformational change, involving the loop 85-90, provides a structural basis for a variety of pH-dependent chemical, physical, and spectroscopic phenomena, collectively known as the Tanford transition.

PubMed: 9760236
DOI: 10.1021/bi981016t

Experimental method

X-RAY DIFFRACTION (2.46 Å)