A Bowman-Birk Inhibitor from the Seeds of Luetzelburgia auriculata Inhibits Staphylococcus aureus Growth by Promoting Severe Cell Membrane Damage

作者：Martins Thiago F; Vasconcelos Ilka M; Silva Rodolpho G G; Silva Fredy D A; Souza Pedro F N; Varela Anna L N; Albuquerque Louise M; Oliveira Jose T A^*

来源：Journal of Natural Products, 2018, 81(7): 1497-1507.

DOI：10.1021/acs.jnatprod.7b00545

Staphylococcus aureus is a multidrug-resistant bacterium responsible for several cases of hospital-acquired infections, which constitute a global public health problem. The introduction of new healthcare strategies and/or the discovery of molecules capable of inhibiting the growth or killing S. aureus would have a huge impact on the treatment of S. aureus-mediated diseases. Herein, a Bowman Birk protease inhibitor (LzaBBI), with strong in vitro antibacterial activity against S. aureus, was purified to homogeneity from Luetzelburgia auriculata seeds. LzaBBI in its native form is a 14.3 kDa protein and has a pI of 4.54, and its NH2-terminal sequence has high identity with other Bowman-Birk inhibitors. LzaBBI showed a mixed-type inhibitory activity against both trypsin and chymotrypsin, respectively, and it remained stable after both boiling at 98 degrees C for 120 min and incubation at various pHs. Scanning electron microscopy revealed that LzaBBI disrupted the S. aureus membrane integrity, leading to bacterial death. This study suggests that LzaBBI is a powerful candidate for developing a new antimicrobial to overcome drug resistance toward reducing hospital-acquired infections caused by S. aureus.

• 出版日期2018-7