Progress on production of collagen-like proteins by expression in Escherichia coli.

The use ofE. colifor the expression of various collagen-like triple helical protein constructs has continued to develop significantly, and certain commercially made proteins are now available. The use of auxotroph designs to assist in the expression of hydroxylated proteins is an important development. A range of other new constructs have been described, including those that contain a segment of a natural collagen sequence and those that are based on collagen-like proteins from prokaryotes, especially the Scl2 protein fromStreptococcus pyogenes. The other constructs that have gained increased attention are those where multiple copies, often 16, of a small native collagen sequence are expressed as tandem repeated sequences, with these being of particular interest for biomedical applications. Ascertaining which construct is being used, however, can create difficulties when the same acronym is used for different constructs, and many are frequently described as 'humanized' even though no sequence changes have been included to make the construct resemble a human sequence more closely.