title: Ecotin: lessons on survival in a protease-filled world.
abstract: Ecotin, an Escherichia coli periplasmic protein of 142 amino acids, has been shown to be a potent inhibitor of a group of homologous serine proteases with widely differing substrate recognition. It is highly effective against a number of enzymes, including both pancreatic and neutrophil-derived elastases, chymotrypsin, trypsin, factor Xa, and kallikrein. Recent structural and functional studies on ecotin and its interactions with different serine proteases have clarified these initial observations and revealed the remarkable features of this protein in inhibiting a strikingly large subset of the chymotrypsin family of serine proteases. The structures of the ecotin:serine protease complexes provide the first examples of protein-protein recognition where the concept of specificity of interactions needs to be reexamined. The binding sites show a fluidity of protein contacts derived from ecotin's innate flexibility in fitting itself to proteases while strongly interfering with their function.
authors.affiliation: Khepri Pharmaceuticals, Inc., South San Francisco, California 94080, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: McGrath
authors.forename: S A
authors.initials: SA
authors.lastname: Gillmor
authors.forename: R J
authors.initials: RJ
authors.lastname: Fletterick
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D033903:Periplasmic Proteins; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C039076:Eco protein, E coli; D029968:Escherichia coli Proteins; D033903:Periplasmic Proteins; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors