Streptomyces erythraeus trypsin inactivates α1-antitrypsin

FEBS Lett. 2011 Dec 15;585(24):3898-902. doi: 10.1016/j.febslet.2011.11.015. Epub 2011 Nov 21.

Abstract

Streptomyces erythraeus trypsin (SET) is a serine protease that is secreted extracellularly by S. erythraeus. We investigated the inhibitory effect of α(1)-antitrypsin on the catalytic activity of SET. Intriguingly, we found that SET is not inhibited by α(1)-antitrypsin. Our investigations into the molecular mechanism underlying this observation revealed that SET hydrolyzes the Met-Ser bond in the reaction center loop of α(1)-antitrypsin. However, SET somehow avoids entrapment by α(1)-antitrypsin. We also confirmed that α(1)-antitrypsin loses its inhibitory activity after incubation with SET. Thus, our study demonstrates that SET is not only resistant to α(1)-antitrypsin but also inactivates α(1)-antitrypsin.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Glycine max / enzymology
  • Hydrolysis
  • Saccharopolyspora / enzymology*
  • Saccharopolyspora / metabolism
  • Trypsin / metabolism*
  • Trypsin Inhibitors / chemistry
  • Trypsin Inhibitors / metabolism
  • alpha 1-Antitrypsin / chemistry
  • alpha 1-Antitrypsin / metabolism*

Substances

  • Trypsin Inhibitors
  • alpha 1-Antitrypsin
  • Trypsin