Interaction of horse plasma antithrombin III and alpha 1-proteinase inhibitor with some serine proteinases.

The research examines how antithrombin III and alpha 1-proteinase inhibitor from horse plasma interact with certain serine proteinases, highlighting their inhibitory effect on some enzymes, but not all.

Objective of the Research

• The primary purpose of this study was to investigate the inhibitory activity of antithrombin III and alpha 1-proteinase inhibitor, isolated from horse citrated plasma, against bovine trypsin, chymotrypsin, and elastase-like neutral proteinase from horse leucocytes.

Methodology

• The researchers simultaneously isolated antithrombin III and alpha 1-proteinase inhibitor from horse plasma. Then, they tested these for inhibitory activity against the specified proteinases.
• The analysis included estimating the stoichiometry of the reaction and the kinetic parameters, such as the association rate constant (kass) and the inhibition constant (Ko).
• The researchers then compared these findings with the protein pattern obtained after exposing the proteinases to the horse inhibitors.
• This comparison analysis was performed using polyacrylamide gel electrophoresis (PAGE and PAGE-SDS).

Findings

• The results showed fast reaction rates and low values of dissociation constants, indicating that the two horse inhibitors effectively inactivate trypsin, a serine proteinase.
• However, antithrombin III showed no inhibitory activity against chymotrypsin or leucocyte elastases, proteolytic enzymes.
• Alpha 1-proteinase inhibitor demonstrated only partial inhibitory effect on chymotrypsin and leucocyte elastases.

Conclusion

• The research concludes that while antithrombin III and alpha 1-proteinase inhibitor from horse plasma display inhibitory activity against trypsin, their effectiveness varies against other serine proteinases.
• This study implies that the interaction and inhibitory action of these proteins can differ depending on the type of enzymes, which could further influence our understanding of the biochemical reactions they participate in.