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The initiating proteases of the complement system: controlling the cleavage

Renee C Duncan1, Lakshmi C Wijeyewickrema, Robert N Pike

  • 1Department of Biochemistry & Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.

Biochimie
|September 14, 2007
PubMed

Insights

The complement system, crucial for immunity, can cause disease when dysregulated. This review details how key proteases like C1r, C1s, and MASP-2 interactions are regulated to control complement activation.

Area of Science:

  • Immunology
  • Biochemistry

Background:

  • The complement system is integral to innate and adaptive immunity.
  • Dysregulation of the complement system is implicated in various diseases.
  • Three main pathways (classical, lectin, alternative) activate the complement cascade.

Purpose of the Study:

  • To review the regulatory mechanisms governing complement-activating proteases.
  • To elucidate the roles of C1r, C1s, and MASP-2 in complement system activation.
  • To understand protease-substrate and protease-inhibitor interactions in complement regulation.

Main Methods:

  • Literature review focusing on complement system proteases.
  • Analysis of molecular mechanisms of protease activation and regulation.
  • Examination of protease interactions with substrates and inhibitors.

Main Results:

  • The classical and lectin pathways share similar protease structures and activation mechanisms.
  • C1r, C1s, and MASP-2 proteases are central to initiating complement activation.
  • Specific interactions with substrates and inhibitors tightly regulate protease activity.

Conclusions:

  • Understanding protease regulation is key to controlling complement-mediated diseases.
  • Targeting these regulatory mechanisms offers therapeutic potential.
  • The review highlights conserved mechanisms in complement activation pathways.

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