Selectivity and stereospecificity of the reactions of dichlorodiammineplatinum(II) with three purified plasma proteins.

Published

Journal Article

The reactions of cis- and trans-dichlorodiammineplatinum(II) (cis- and trans-DDP) with albumin and two plasma proteinase inhibitors were compared. Reaction with alpha 2-macroglobulin (alpha 2M) resulted in subunit crosslinking and loss of proteinase binding activity. The reaction also modified a receptor recognition site present on each alpha 2M subunit. While more trans-DDP was incorporated into alpha 2M than cis-DDP, cis-DDP was more effective at blocking receptor recognition, alpha 1-proteinase inhibitor was also inactivated by reaction with either cis- or trans-DDP. These reactions resulted in binding of platinum to methionine-358 at the reactive center of this inhibitor. Trans-DDP, however, was less selective and also bound to the single cysteine residue (Cys-232) of alpha 1PI. Reaction of albumin with cis-DDP resulted in incorporation of about 1 mol platinum per mol protein, and this platinum modified the single cysteine (Cys-34) in the molecule. Albumin incorporated twice as much trans-DDP, but the binding did not involve cysteine-34. In general, reactions of cis-DDP with proteins appear to be more selective than those observed for modification with the trans isomer.

Full Text

Duke Authors

Cited Authors

  • Pizzo, SV; Swaim, MW; Roche, PA; Gonias, SL

Published Date

  • May 1988

Published In

Volume / Issue

  • 33 / 1

Start / End Page

  • 67 - 76

PubMed ID

  • 2454291

Pubmed Central ID

  • 2454291

International Standard Serial Number (ISSN)

  • 0162-0134

Digital Object Identifier (DOI)

  • 10.1016/0162-0134(88)80035-7

Language

  • eng

Conference Location

  • United States