Analysis of Protein Glycosylation after Rapid Digestion Using Protease-Containing Membranes in Spin Columns.

Glycosylation is an important protein post-translational modification that plays a pivotal role in the bioactivity of therapeutic proteins and in the infectivity of viral proteins. Liquid chromatography with tandem mass spectrometry readily identifies protein glycans with site specificity. However, the overnight incubation used in conventional in-solution proteolysis leads to high turnaround times for glycosylation analysis, particularly when sequential in-solution digestions are needed for site-specific glycan identification. Using bovine fetuin as a model glycoprotein, this work first shows that in-membrane digestion in ∼3 min yields similar glycan identification and quantitation when compared to overnight in-solution digestion. Protease-containing membranes in a spin column enable digestion of therapeutic proteins (trastuzumab and erythropoietin) and a viral protein (SARS-CoV-2 receptor binding domain) in ∼30 s. Glycan identification is similar after in-solution and in-membrane digestion, and limited in-membrane digestion enhances the identification of high-mannose glycans in trastuzumab. Finally, stacked membranes containing trypsin and chymotrypsin allow fast sequential proteolytic digestion to site-specifically identify the glycans of SARS-CoV-2 receptor binding domain. One can easily assemble the protease-containing membranes in commercial spin columns, and spinning multiple columns simultaneously will facilitate parallel analyses.

Research progress in the enhancement technology of soil vapor extraction of volatile petroleum hydrocarbon pollutants.

At present, volatile petroleum hydrocarbon pollution in soil is still widespread and serious in China. Among the treatment methods for contaminated soil, soil vapor extraction technology is widely used in in situ remediation of volatile petroleum hydrocarbon-contaminated soil due to its simple equipment, easy installation, convenient operation and high remediation efficiency. In this paper, the present situation of volatile organic compounds (VOCs) contaminated by petroleum hydrocarbons is reviewed. The effects of soil permeability, pollutant characteristics, soil moisture content, ambient temperature, and gas extraction flow rate on soil vapor extraction are discussed. Moreover, five different types of soil vapor extraction enhancement technologies, characteristics, research and applications are introduced, and the development prospect of soil remediation industry is presented.