Speaker: Robert Cole, Johns Hopkins University School of Medicine

Topic: What’s on your albumin?

Date: Monday, March 20, 2023

Time: 6:15 pm Dinner, 7:15 pm Presentation

Location: Shimadzu Scientific Instrument, Inc. Training Center 7100 Riverwood Drive, Columbia, MD 21046 (Directions)
This will be an in-person meeting. Attendees are required to show a vaccine card (either at the door or in advance using the web form) . If you have submitted your vaccine card before, your status is already recorded.

Dinner: Please RSVP to Andy Qi (andy.yue.qi@gmail.com) by Friday, March 17 if you will be attending the dinner.

Abstract: Environmental exposures contribute to chronic disease risk substantially more than heritable genetic variants. Outdoor air pollution is a complex environmental
mixture which is responsible for over 4 million deaths each year, an impact that is projected to rise over the next several decades. The International Agency for Research on Cancer (IARC) has declared outdoor air pollution to be Group 1 human carcinogen. Outdoor air is a complex mixture of volatile organic toxins and carcinogens (e.g., aldehydes and benzene), sulfur dioxide, nitrogen oxides, polycyclic aromatic hydrocarbons, and particulate matter. Assessing personal exposure to environmental toxicants in complex mixtures, such as outdoor air pollution, is a critical challenge for predicting disease risk. Thus, developing and validating biomarkers which reveal exposure to these complex mixtures would advance individual risk analysis. Using human serum albumin (HSA)-based biomonitoring, we reported dosimetric relationships between adducts at HSA Cys34 and ambient air pollutant levels. However, modifications at other sites in HSA may reveal a great number of novel adducts and provide a panel of exposure biomarkers for disease risk. To bridge this gap, we developed a novel untargeted mass spectrometry-based method, termed Pan-Protein Adductomics (PPA),
to agnostically detect and quantify modifications at multiple residues in human serum albumin (HSA). Our PPA method combines nanoflow-liquid chromatography, gas-phase fractionation, overlapping-window data-independent acquisition, and high-resolution tandem mass spectrometry to assay modifications on HSA. Our initial application of PPA is to assess temporal changes in HSA modifications in non-smoking women exposed to high levels of outdoor air pollution. While we are currently focused on modifications in albumin, the PPA approach is applicable to any protein and may expand the knowledge base of protein modifications.

Thank you to our 2022-2023 sponsors!

Speaker: Zachary Goecker, NIST

Topic: Developing Reproducible Methods in Site-Specific Glycosylation Analysis

Date: Monday, February 27, 2023

Time: 6:15 pm Dinner, 7:15 pm Presentation

Location: Shimadzu Scientific Instrument, Inc. Training Center 7100 Riverwood Drive, Columbia, MD 21046 (Directions)
This will be an in-person meeting. Attendees are required to show a vaccine card (either at the door or in advance using the web form) . If you have submitted your vaccine card before, your status is already recorded.

Dinner: Please RSVP to Andy Qi (andy.yue.qi@gmail.com) by Friday, February 24 if you will be attending the dinner.

Abstract: Many proteins are glycosylated at multiple sites, and each site can contain complex
distributions of attached glycans. Until recently, reliable determinations of these distributions have not been possible. Instead, glycosylation analysis of glycoproteins has been primarily accomplished by releasing and identifying glycans, thereby losing all protein site-specific information. This glycomics approach works well for understanding the diversity of glycosylation in a digest, but does not answer questions relevant to site-specific structures (glycan microheterogeneity) and therefore is not as useful in determining direct functional implications. Recent developments in high resolution mass spectrometry have opened the door for the identification of intact glycopeptides. This study assesses methods in site-specific analysis of intact glycopeptides to demonstrate
reproducibility and measure variation in glycosylation quantitatively between different experimental factors. Here, we report the use of stepped HCD fragmentation, contingent ion scan, and many downstream data filters for the production of highly robust and reproducible glycosylation distribution spectra. In this presentation, we will report site-specific glycosylation profiles on glycoproteins from Sars-Cov-2, influenza, blood serum, and breastmilk. Results demonstrate that glycosylation profiles are highly reproducible among replicates and different digestion methods. However, glycosylation patterns do change based on factors such as source, proteins sequence, and glycosylation site.

Thank you to our 2022-2023 sponsors!