title: Streptomyces erythraeus trypsin inactivates α1-antitrypsin.
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.
authors: Case Center for Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH 44106-4988, USA.
authors: Krishna M
authors: KM
authors: Vukoti
authors: Chandra Sekhar Rao
authors: CS
authors: Kadiyala
authors: Masaru
authors: M
authors: Miyagi
mesh_terms: D055162:Biocatalysis; D006868:Hydrolysis; D016930:Saccharopolyspora / Q000201:enzymology* / Q000378:metabolism; D013025:Glycine max / Q000201:enzymology; D014357:Trypsin / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014361:Trypsin Inhibitors; D000515:alpha 1-Antitrypsin; D014357:Trypsin