A snake venom metalloproteinase that inhibited cell proliferation and induced morphological changes of ECV304 cells

Area of Science:

• Biochemistry
• Molecular Biology
• Toxicology

Background:

• Snake venom metalloproteinases (SVMPs) are crucial toxins involved in envenomation.
• SVMPs exhibit diverse enzymatic activities and biological effects, including fibrinogenolysis and cytotoxicity.
• Understanding specific SVMP functions is vital for developing antivenoms and therapeutic agents.

Purpose of the Study:

• To purify and characterize TSV-DM, a metalloproteinase from Trimeresurus stejnegeri venom.
• To investigate the enzymatic activity of TSV-DM on fibrinogen.
• To determine the effects of TSV-DM on ECV304 cell proliferation, morphology, and apoptosis.

Main Methods:

• Purification of TSV-DM from Trimeresurus stejnegeri venom.
• Degradation assays using fibrinogen (Aalpha and Bbeta chains).
• cDNA cloning and sequencing to determine the full-length protein sequence.
• Peptide mass fingerprinting for protein sequence confirmation.
• Cell culture experiments (ECV304 cells) to assess proliferation, morphology, DNA fragmentation, and DNA content.

Main Results:

• TSV-DM (110kDa) was purified and its cDNA encoded a 622-amino acid polypeptide.
• TSV-DM exhibited dose-dependent degradation of fibrinogen, preferentially targeting the Aalpha chain over the Bbeta chain.
• The deduced protein sequence showed high homology to subclass P-IIIb SVMPs.
• TSV-DM transiently inhibited ECV304 cell proliferation and induced morphologic changes.
• TSV-DM did not induce apoptosis in ECV304 cells, as evidenced by DNA fragmentation and DNA content analysis.

Conclusions:

• TSV-DM is a P-IIIb subclass snake venom metalloproteinase with potent fibrinogenolytic activity.
• While TSV-DM affects cell proliferation and morphology, it does not induce apoptosis in ECV304 cells.
• The findings contribute to the understanding of SVMP diversity and function, distinguishing TSV-DM from other apoptosis-inducing SVMPs.