Enhanced reproducibility of the human gel-based tear proteome maps in the presence of di-(2-hydroxyethyl) disulfide

Optimized Proteome Reduction for Integrative Top–Down Proteomics

Integrative top–down proteomics is an analytical approach that fully addresses the breadth and complexity needed for effective and routine assessment of proteomes. Nonetheless, any such assessments also require a rigorous review of methodology to ensure the deepest possible quantitative proteome analyses. Here, we establish an optimized general protocol for proteome extracts to improve the reduction of proteoforms and, thus, resolution in 2DE. Dithiothreitol (DTT), tributylphosphine (TBP), and 2-hydroxyethyldisulfide (HED), combined and alone, were tested in one-dimensional SDS-PAGE (1DE), prior to implementation into a full 2DE protocol. Prior to sample rehydration, reduction with 100 mM DTT + 5 mM TBP yielded increased spot counts, total signal, and spot circularity (i.e., decreased streaking) compared to other conditions and reduction protocols reported in the literature. The data indicate that many widely implemented reduction protocols are significantly ‘under-powered’ in terms of proteoform reduction and thus, limit the quality and depth of routine top–down proteomic analyses.

Optimizing the Preparation Procedure of Recombinant PSCA, as a Practical Biomarker in Prostate Cancer

Background:

The unique expression pattern of prostate stem cell antigen (PSCA) in a number of prevalent neoplasms has made the antigen a great target for cancer researches, and many clinical methods have been developed based on the application of this tumor marker. Hence, optimal PSCA laboratory production can be considered a hallmark for many researchers.

Objective:

An analytical study was designed to improve the quality and quantity of PSCA production.

Materials and Methods:

The effects of different compositions of lysis buffers and some ultrasound durations were assessed by calculation of the protein recovery followed by PSCA specific blotting experiments. Then, based on the results of the web-based characterization, interference removal, followed by re-solubilization of the protein in various buffers, was designed, applied, and assessed.

Results:

Since the selection of an appropriate methodology depends merely on the research purposes, we tried to discuss the pros and cons of the investigated methods according to the hydrophobic nature of PSCA as well as its dramatic tendency to aggregate in the form of inclusion bodies in the expression hosts.

Conclusions:

We introduced a newly designed method to fit the delicate immunological surveys and overcome some limiting factors in PSCA production.