Modification of the tandem reactive centres of human inter-alpha-trypsin inhibitor with butanedione and cis-dichlorodiammineplatinum(II).

Journal Article (Journal Article)

Human inter-alpha-trypsin inhibitor (I alpha I) is a plasma proteinase inhibitor active against cathepsin G, leucocyte elastase, trypsin and chymotrypsin. It owes its broad inhibitory specificity to tandem Kunitz-type inhibitory domains within an N-terminal region. Sequence studies suggest that the reactive-centre residues critical for inhibition are methionine and arginine. Reaction of I alpha I with the arginine-modifying reagent butane-2,3-dione afforded partial loss of inhibitory activity against both cathepsin G and elastase but complete loss of activity against trypsin and chymotrypsin. Reaction of I alpha I with the methionine-modifying reagent cis-dichlorodiammineplatinum(II) resulted in partial loss of activity against cathepsin G and elastase but did not affect inhibition of either trypsin or chymotrypsin. Employment of both reagents eliminated inhibition of cathepsin G and elastase. These findings suggest that both cathepsin G and elastase are inhibited at either of the reactive centres of I alpha I. Trypsin and chymotrypsin, however, appear to be inhibited exclusively at the arginine reactive centre.

Full Text

Duke Authors

Cited Authors

  • Swaim, MW; Pizzo, SV

Published Date

  • August 15, 1988

Published In

Volume / Issue

  • 254 / 1

Start / End Page

  • 171 - 178

PubMed ID

  • 2460086

Pubmed Central ID

  • PMC1135053

International Standard Serial Number (ISSN)

  • 0264-6021

Digital Object Identifier (DOI)

  • 10.1042/bj2540171


  • eng

Conference Location

  • England