METHODS: This study examined the composition purity of PCAV through a decomplexation proteomic approach, applying size-exclusion chromatography (SEC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and tandem mass spectrometry liquid chromatography-tandem mass spectrometry (LC-MS/MS).
RESULTS: SDS-PAGE and SEC showed that the major protein in PCAV (constituting ∼80% of total proteins) is approximately 110 kDa, consistent with the F(ab')2 molecule. This protein is reducible into two subunits suggestive of the light and heavy chains of immunoglobulin G. LC-MS/MS further identified the proteins as equine immunoglobulins, representing the key therapeutic ingredient of this biologic product. However, protein impurities, including fibrinogens, alpha-2-macroglobulins, albumin, transferrin, fibronectin and plasminogen, were detected at ∼20% of the total antivenom proteins, unveiling a concern for hypersensitivity reactions.
CONCLUSIONS: Together, the findings show that PCAV contains a favorable content of F(ab')2 for neutralization, while the antibody purification process awaits improvement to minimize the presence of protein impurities.
METHODS: Eutopic endometrium and serum from patients with endometriosis (n = 8 for tissue and n = 4 for serum) are, respectively, compared to endometrium and serum from females without endometriosis (n = 8 for tissue and n = 4 for serum) using a shotgun quantitative proteomics method. All study participants are at the proliferative phase of their menstrual cycle.
RESULTS: At the tissue and serum level, 1214 and 404 proteins are differentially expressed (DEPs) in eutopic endometrium and serum, respectively, of women with endometriosis versus controls. Gene ontology analysis shows that terms related to immune response/inflammation, cell adhesion/migration, and blood coagulation are significantly enriched in the DEPs of eutopic endometrium, as well as serum. Twenty-one DEPs have the same trend of differential expression in both matrices and can be further examined as potential disease- and tissue-specific serological markers of endometriosis.
CONCLUSIONS: The present integrated proteomic profiling of eutopic endometrium and serum from women with endometriosis identify promising serological markers that can be further validated in larger cohorts for the minimally invasive diagnosis of endometriosis.
SIGNIFICANCE: A shotgun proteomic approach adopted in this study revealed the compositional details of the venom of common tiger snake from Australia, Notechis scutatus. The proteomic findings provided additional information on the relative abundances of toxins and the detection of proteins of minor expression unreported previously. The potent lethal effect of the venom was neutralized by bioCSL Sea Snake Antivenom, an anticipated finding due to the fact that the Sea Snake Antivenom is actually bivalent in nature, being raised against a mix of venoms of the beaked sea snake (Hydrophis schistosus) and N. scutatus. However, it is surprising to note that bioCSL Sea Snake Antivenom neutralized N. scutatus venom much more effectively compared to the targeted sea snake venom by a marked difference in potency of approximately 6-fold. This phenomenon may be explained by the main difference in the proteomes of the two venoms, where H. schistosus venom is dominated by short-neurotoxins in high abundance - this is a poorly immunogenic toxin group that has been increasingly recognized in the venoms of a few cobras. Further investigations should be directed toward strategies to improve the neutralization of short-neurotoxins, in line with the envisioned production of an effective pan-regional elapid antivenom.