Unraveling the processing and activation of snake venom metalloproteinases

J Proteome Res. 2014 Jul 3;13(7):3338-48. doi: 10.1021/pr500185a. Epub 2014 Jun 18.

Abstract

Snake venom metalloproteinases (SVMPs) are zinc-dependent enzymes responsible for most symptoms of human envenoming. Like matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase (ADAM) proteins, SVMPs are synthesized as zymogens, and enzyme activation is regulated by hydrolysis of their prodomain, but the processing of SVMPs is still unclear. In this study, we attempted to identify the presence of prodomain in different compartments of snake venom glands as zymogens or in the free form to elucidate some mechanism involved in SVMP activation. Using antibodies obtained by immunization with a recombinant prodomain, bands of zymogen molecular mass and prodomain peptides were detected mostly in gland extracts all along the venom production cycle and in the venom collected from the lumen at the peak of venom production. Prodomain was detected in secretory cells mostly in the secretory vesicles near the Golgi. We hypothesize that the processing of SVMPs starts within secretory vesicles and continues in the lumen of the venom gland just after enzyme secretion and involves different steps compared to ADAMs and MMPs but can be used as a model for studying the relevance of peptides resulting from prodomain processing and degradation for controlling the activity of metalloproteinases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bothrops / anatomy & histology
  • Bothrops / metabolism
  • Crotalid Venoms / enzymology*
  • Enzyme Activation
  • Exocrine Glands / cytology
  • Exocrine Glands / enzymology
  • Female
  • Metalloproteases / chemistry
  • Metalloproteases / metabolism*
  • Molecular Sequence Data
  • Protein Precursors / chemistry
  • Protein Precursors / metabolism*
  • Protein Transport
  • Reptilian Proteins / chemistry
  • Reptilian Proteins / metabolism*
  • Sequence Homology, Amino Acid

Substances

  • Crotalid Venoms
  • Protein Precursors
  • Reptilian Proteins
  • Metalloproteases