PMID: 23155056

Authors:

Makabe K, Nakamura T, Kuwajima K

Title:

Structural insights into the stability perturbations induced by N-terminal variation in human and goat alpha-lactalbumin.

Journal:

Protein Eng Des Sel. 2013 Feb;26(2):165-70. doi: 10.1093/protein/gzs093. Epub, 2012 Nov 14.

Abstract:

Addition of an extra methionine at the N-terminus by recombinant expression of alpha-lactalbumin in Escherichia coli significantly destabilizes the protein, and this destabilization has hampered mutational analyses such as the mutational phi-value analysis of the protein. Deletion of residue 1 from the recombinant form recovers the stability in human and goat alpha-lactalbumin. Here, we thus determined the crystal structures of the residue 1-deletion variants of recombinant human and goat alpha-lactalbumin, and compared the structures with those of the authentic and recombinant forms. The results demonstrate the importance of the N-terminal backbone structure and hydrogen-bonding pattern for the stability of alpha-lactalbumin.