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Streptomyces erythraeus trypsin inactivates α1-antitrypsin
Krishna M Vukoti1, Chandra Sekhar Rao Kadiyala, Masaru Miyagi
1Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106-4988, USA.
None:
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.
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