1.Inhibition of streptococcal pyrogenic exotoxin B using allicin from garlic.
Arzanlou M1. Microb Pathog. 2016 Apr;93:166-71. doi: 10.1016/j.micpath.2016.02.010. Epub 2016 Feb 18.
Streptococcal pyrogenic exotoxin B (SpeB) is an important virulence factor of group A streptococci (GAS) and inactivation of SpeB results in the significantly decreased virulence of the bacterium. The protein is secreted as an inactive zymogen of 40 KDa (SpeBz) and undergoes proteolytic truncation to result in a 28 KDa mature active protease (SpeBm). In this study the effect of allicin on the proteolytic activity of SpeBm was evaluated using azocasein assay. Allicin neutralized the SpeBm proteolytic activity in a concentration dependent manner (IC50 = 15.71 ± 0.45 μg/ml). The loss of activity was completely reversed by subsequent treatment with a reducing agent, dithiothreitol (DTT; 10 mM final concentration), suggesting that allicin likely inhibits the SpeBm by forming a disulfide linkage with an active thiol group in its active site. This mechanism of action was further confirmed with the fact that DTT did not reverse the SpeBm activity in the presence of E-64, a cysteine protease-specific inhibitor, which works specially by forming a thioether linkage with free sulfhydryl groups in enzymes active site.
2.Proteomic analysis and purification of an unusual germin-like protein with proteolytic activity in the latex of Thevetia peruviana.
de Freitas CD1, da Cruz WT2, Silva MZ2, Vasconcelos IM2, Moreno FB3, Moreira RA3, Monteiro-Moreira AC3, Alencar LM4, Sousa JS4, Rocha BA2, Ramos MV2. Planta. 2016 Jan 21. [Epub ahead of print]
MAIN CONCLUSION: The latex from Thevetia peruviana is rich in plant defense proteins, including a 120 kDa cysteine peptidase with structural characteristics similar to germin-like proteins. More than 20,000 plant species produce latex, including Apocynaceae, Sapotaceae, Papaveraceae and Euphorbiaceae. To better understand the physiological role played by latex fluids, a proteomic analysis of Thevetia peruviana (Pers.) Schum latex was performed using two-dimensional gel electrophoresis and mass spectrometry. A total of 33 proteins (86 %) were identified, including storage proteins, a peptidase inhibitor, cysteine peptidases, peroxidases and osmotins. An unusual cysteine peptidase, termed peruvianin-I, was purified from the latex by a single chromatographic step involving gel filtration. The enzyme (glycoprotein) was inhibited by E-64 and iodoacetamide and exhibited high specific activity towards azocasein (K m 17.6 µM), with an optimal pH and temperature of 5.
3.Symptomatic endometriosis of the posterior cul-de-sac is associated with impaired sleep quality, excessive daytime sleepiness and insomnia: a case-control study.
Leone Roberti Maggiore U1, Bizzarri N1, Scala C1, Tafi E1, Siesto G2, Alessandri F3, Ferrero S4. Eur J Obstet Gynecol Reprod Biol. 2015 Nov 29. pii: S0301-2115(15)00425-X. doi: 10.1016/j.ejogrb.2015.11.026. [Epub ahead of print]
OBJECTIVE: To assess the impact of endometriosis of the posterior cul-de-sac on quality of sleep, average daytime sleepiness and insomnia.
4.Molecular characterization of a cathepsin F-like protease in Trichinella spiralis.
Qu ZG1, Ma XT2, Li WH3, Zhang NZ4, Yue L5, Cui JM6, Cai JP7,8, Jia WZ9,10, Fu BQ11,12. Parasit Vectors. 2015 Dec 21;8:652. doi: 10.1186/s13071-015-1270-y.
BACKGROUND: Trichinellosis is a re-emerging infectious disease, caused by Trichinella spp. Cathepsin F belongs to cysteine protease that is a major virulence factor for parasitic helminths, and it may be a potential anti-helminth drug target and vaccine candidate. The aim of this study was to clone, express and identify a cathepsin F-like protease in Trichinella spiralis and to investigate its biochemical characteristics.
