Peptidomic Analysis and Antimicrobial Activity of Serum Peptide from Hevea brasiliensis Clone BPM24.

BACKGROUND: Hevea brasiliensis is severely affected by the fungal disease caused by Phytophthora spp. Significant loss of rubber yield is widespread and extensive use of chemical fungicides has resulted in health and environmental problems. OBJECTIVE: This work aims to extract and identify the latex serum peptides from a disease tolerant clone of H. brasiliensis, and study the inhibitory efficacy against pathogenic bacteria and fungi. METHODS: Serum peptides were extracted from H. brasiliensis BPM24 using mixed lysis solution. Low molecular weight peptides were screened and fractionated by solid-phase extraction and then identified by tandem mass spectrometry. Total and fractionated serum peptides were assayed for bacterial and fungal inhibition using broth microdilution and poisoned food methods. An inhibitory control study in the greenhouse was also performed using susceptible clones for pre and postinfection with Phytophthora spp. RESULTS: Forty-three serum peptide sequences were successfully identified. Thirty-four peptides matched with the proteins associated with plant defense response signaling, host resistance, and adverse environmental factors. The inhibitory study of total serum peptides demonstrated antibacterial and anti-fungal properties. The greenhouse study exhibited disease inhibitory efficacy of 60% for the treatment of Phytophthora spp. in post-infected plants and 80% for pre-treated samples. CONCLUSION: Latex serum peptides from disease tolerant H. brasiliensis revealed several proteins and peptides associated with plant defense and disease resistance. The peptides play a vital role for defense against bacteria and fungi pathogens, including Phytophthora spp. Enhanced disease protection can be obtained when the extracted peptides were applied to the susceptible plants before exposure to the fungi. These findings provided an insight and may pave the way for the development of biocontrol peptides from natural resources.

Analysis and comparison of tear protein profiles in dogs using different tear collection methods.

BACKGROUND: Tear proteomic analysis has become an important tool in medical and veterinary research. The tear collection method could influence the tear protein profile. This study aims to evaluate the protein profiles of dog tears collected using microcapillary tubes (MT), Schirmer tear strips (ST), and ophthalmic sponges (OS). METHODS: The tear samples were collected using MT, ST, and OS. Tear protein profiles were analyzed using two-dimensional electrophoresis (2-DE) and the different protein spots' expression was compared. Fourteen protein spots were identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Tear protein concentrations ranged from 2.80 to 4.03 µg/µL, with no statistically significant differences among collection methods. Protein expression in each collection method differed in terms of both the number and intensity of the spots. There were 249, 327, and 330 protein spots found from tears collected with MT, ST, and OS, respectively. The proteins albumin, haptoglobin, and lactoferrin identified from OS were found to have higher spot intensities than other methods of collection. The use of MT demonstrated the downregulation of nine proteins. CONCLUSIONS: The recent study supported that tear protein analysis is affected by different tear collection methods. Although ST is commonly used for tear collection, it provides insufficient information to study particular tear proteins.

Caspase-3, a shrimp phosphorylated hemocytic protein is necessary to control YHV infection.

By using immunohistochemistry detection, yellow head virus (YHV) was found to replicate in granule-containing hemocytes including semi-granular hemocytes (SGC) and granular hemocytes (GC) during the early phase (24 h post injection) of YHV-infected shrimp. Higher signal of YHV infection was found in GC more than in SGC. Comparative phosphoproteomic profiles between YHV-infected and non-infected GC reveal a number of phosphoproteins with different expression levels. The phosphoprotein spot with later on identified as caspase-3 in YHV-infected GC is most interesting. Blocking caspase-3 function using a specific inhibitor (Ac-DEVD-CMK) demonstrated high replication of YHV and consequently, high shrimp mortality. The immunohistochemistry results confirmed the high viral load in shrimp that caspase-3 activity was blocked. Caspase-3 is regulated through a variety of posttranslational modifications, including phosphorylation. Analysis of phosphorylation sites of shrimp caspase-3 revealed phosphorylation sites at serine residue. Taken together, caspase-3 is a hemocytic protein isolated from shrimp granular hemocytes with a role in anti-YHV response and regulated through the phosphorylation process.

Proteomic analysis and white spot syndrome virus interaction of mud crab (Scylla olivacea) revealed responsive roles of the hemocytes.

White spot disease (WSD) is a highly virulent viral disease in shrimps. Clinical signs and high mortality of WSD is generally observed after a few days of infection by White Spot Syndrome virus (WSSV). Mud crabs are the major carrier and persistent host for the WSSV. However, an elucidation of viral interaction and persistent mode of WSSV infection in mud crab is still limited. We investigated the defensive role of mud crab (Scylla olivacea) hemocytes against WSSV infection by using comparative proteomic analysis coupled with electrospray ionization liquid chromatography tandem mass spectrometry (ESI-LC/MS/MS). The proteomic maps of expressed proteins obtained from WSSV infected hemocytes revealed differential proteins related to various biological functions, including immune response, anti-apoptosis, endocytosis, phosphorylation signaling, stress response, oxygen transport, molting, metabolism, and biosynthesis. Four distinctive cell types of crab hemocytes: hyaline cells (HC), small granular cells (SGC), large granular cells (LGC) and mixed granular cells (MGC) were found susceptible to WSSV. However, immunohistochemistry analysis demonstrated a complete replication of WSSV only in SGC and LGC. WSSV induced apoptosis was also observed in HC, SGC and MGC except for LGC. These results suggested that HC and MGC may undergo apoptosis prior to a complete assembly of virion, while SGC is more susceptible showing higher amplification and releasing of virion. In contrast, WSSV may inhibit apoptosis in infected LGC to stay in latency. This present finding provides an insight for the responsive roles of crustacean hemocyte cells involved in molecular interaction and defense mechanism against WSSV.