Structural evidence for the presence of a secondary calcium binding site in human alpha-lactalbumin.
Article Details
- CitationCopy to clipboard
Chandra N, Brew K, Acharya KR
Structural evidence for the presence of a secondary calcium binding site in human alpha-lactalbumin.
Biochemistry. 1998 Apr 7;37(14):4767-72.
- PubMed ID
- 9537992 [ View in PubMed]
- Abstract
The high-resolution X-ray crystal structure of human alpha-lactalbumin (at 1.8 A) in the presence of an elevated level of calcium reveals a new secondary calcium binding site, 7.9 A away from the primary calcium binding site known in all alpha-lactalbumin structures so far. The new calcium binding site is different from the zinc and sulfate binding sites [Ren, J., et al. (1993) J. Biol. Chem. 268, 19292-19298] but shares common features with the manganese binding site as described by Gerkin [Gerkin, T. A. (1984) Biochemistry 23, 4688-4697]. The proximity of the manganese and calcium binding region and the location of the functional site on one side of the charged surface of the alpha-lactalbumin molecule suggest that these binding sites might play a role in the formation of the lactose synthase complex.