title: Aggregation of chymotrypsinogen: portrait by infrared spectroscopy.
abstract: Changes in the secondary structure and aggregation of chymotrypsinogen were investigated by infrared difference spectroscopy in conjunction with temperature and pressure tuning IR spectroscopy; both the amide I' band and side chain bands were studied. A prominent component of the amide I' band in the difference spectrum obtained upon cooling a chymotrypsinogen solution, or increasing the hydrostatic pressure, was observed in the region between 1627 and 1622 cm-1. Under denaturing conditions a white gel was formed, which is attributed to irreversible self-association or aggregation. This process was accompanied by the appearance of two new amide I' bands in the infrared spectrum of the protein: a very strong band at 1618 cm-1 and a weak band at 1685 cm-1. These bands are assigned to peptide segments with anti-parallel aligned beta-strands.
authors.affiliation: Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa.
authors.forename: A A
authors.initials: AA
authors.lastname: Ismail
authors.forename: H H
authors.initials: HH
authors.lastname: Mantsch
authors.forename: P T
authors.initials: PT
authors.lastname: Wong
mesh_terms: D002919:Chymotrypsinogen / Q000737:chemistry*; D046911:Macromolecular Substances; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared / Q000379:methods; D013816:Thermodynamics
chemical_list: D046911:Macromolecular Substances; D002919:Chymotrypsinogen