The characteristic of a protein that may change during a DNA mutation is shape.
Mutations in the DNA can affect the sequence of amino acids in a protein, which in turn can alter its three-dimensional structure or shape. Changes in shape can impact how the protein functions, including its activity, stability, and interactions with other molecules. Hardness, color, and texture are not direct characteristics of proteins; they may be influenced by protein shape but are not typically described in relation to protein mutations.