2Z2E

Crystal Structure of Canine Milk Lysozyme Stabilized against Non-enzymatic Deamidation

Summary for 2Z2E

• Entry DOI: 10.2210/pdb2z2e/pdb
• Descriptor: Lysozyme C, milk isozyme, SULFATE ION (3 entities in total)
• Functional Keywords: lysozyme c, milk lysozyme, 1, 4-beta-n-acetylmuramidase c, bacteriolytic enzyme, hydrolase
• Biological source: Canis lupus familiaris (dog)
• Total number of polymer chains: 2
• Total formula weight: 29313.27

Authors

Nonaka, Y.,Akieda, D.,Watanabe, N.,Tanaka, I.,Kamiya, M.,Aizawa, T.,Nitta, K.,Demura, M.,Kawano, K. (deposition date: 2007-05-21, release date: 2007-11-27, Last modification date: 2024-11-06)

Primary citation

Nonaka, Y.,Aizawa, T.,Akieda, D.,Yasui, M.,Watanabe, M.,Watanabe, N.,Tanaka, I.,Kamiya, M.,Mizuguchi, M.,Demura, M.,Kawano, K.
Spontaneous asparaginyl deamidation of canine milk lysozyme under mild conditions
Proteins, 72:313-322, 2008

PubMed Abstract: Asparaginyl deamidation is a common form of nonenzymatic degradation of proteins and peptides. As it introduces a negative charge spontaneously and irreversibly, charge heterogeneity can be accumulated in protein solution during purification, preservation, and experiments. In this study, canine milk lysozyme (CML), a useful model for the study of the molten globule state, exhibited charge heterogeneity after sample purification. Four Asn residues in CML deamidated rapidly under mild conditions: pH 8.0 and 30 degrees C. Other than these residues, one Asn residue, which was stable in the native state, was labile to deamidation in the unfolded state. This suggests that the structural formation around Asn can suppress deamidation. Substitutions of these labile Asn residues to Gln residues prevented deamidation effectively. Because the substitutions did not disrupt the structural formation of the native and molten globule states, they will enable more precise analyses for physical and structural studies.

PubMed: 18214981
DOI: 10.1002/prot.21927

Experimental method

X-RAY DIFFRACTION (2.01 Å)