Double-headed protease inhibitors from black-eyed peas. VI. Singlet-singlet energy transfer and other optical studies on the structure of trypsin and chymotrypsin complexes.

摘要: The geometry of the binary and ternary complexes two black-eyed pea inhibitors with trypsin chymotrypsin has been established by distance measurements using technique singlet-singlet energy transfer. Triangulation measured distances in double-headed complex trypsin-chymotrypsin inhibitor (BEPCI) limits possible structural models for this to those which center between is about 64 A, from single fluorescently labeled tyrosyl residue BEPCI dimer 33 tyrosine 43 A. Energy transfer results (BEPTI) show conclusively that weak site structurally analogous strong binding BEPCI. BEPTI sites BEPTI. Corresponding are same, indicating little or no rearrangement occurs when formed. Complex formation was shown involve tryptophan tryosine residues both as judged absorption circular dichroism difference spectroscopy. In addition, spectra revealed some disulfide contributions.