Dr Alan J. Stewart
Reader in Molecular Medicine
Tel: 01334 463546
https://orcid.org/0000-0003-4580-1840
Research summary
Our work currently spans three main areas:
1. Zinc, Fatty Acids, and Thrombotic Risk in Diabetes
Type 2 diabetes (T2D) affects nearly half a billion people globally, with cardiovascular disease, a leading cause of death in T2D. A key contributor is an enhanced thrombotic environment, driven by abnormal interactions between platelets and coagulation proteins. We have identified a novel mechanism in which elevated non-esterified fatty acids (NEFAs)—common in diabetes—disrupt zinc (Zn²⁺) binding to albumin, increasing free Zn²⁺ availability. This promotes Zn²⁺-dependent changes in fibrin clot structure and platelet function. Our work funded by the British Heart Foundation, is investigating how Zn²⁺ directly modulates fibrin network formation and its interactions with platelets and haemostatic molecules, providing new insight into thrombosis risk in diabetes.
2. Magnesium and Fibrinolysis in Type 1 Diabetes
Vascular complications and increased thrombotic risk are major concerns in type 1 diabetes (T1D). We have identified lower plasma magnesium levels in individuals with T1D compared to controls, with this deficiency linked to hypofibrinolysis—a predictor of cardiovascular outcomes. We hypothesise that adequate magnesium is critical for normal haemostasis and are exploring how magnesium regulates fibrinolysis, whether supplementation improves thrombotic profiles and patient outcomes, and whether it causes structural changes in fibrinogen or plasminogen. Funded by Diabetes UK, our goal is to evaluate magnesium supplementation as a safe, cost-effective strategy to reduce cardiovascular risk in T1D.
3. Quantitative Proteomics and Metal-Protein Interactions
In collaboration with Dr. Sally Shirran, we’ve employed SWATH-MS proteomics to quantify hundreds of plasma proteins from minimal samples. This has enabled discovery of potential markers in macular degeneration and immune cell differentiation. We are now applying this to cancer diagnostics and to understand haemostatic changes triggered by metabolic disease states. We are also developing “speciomic” approaches to explore metal-protein interactions.
Selected Recent Publications (Full list is available here)
Lin, B, Alexander, R, Fritzen, R, Mills, S, Stewart, AJ & McCowan, C 2025, ‘Abnormal plasma/serum magnesium, copper and zinc concentrations associate with the future development of cardiovascular diseases.‘ Nutrients, vol 17, 1447.
Ahmed, H, Fernandes, MF, Abbas, K, Synowsky, SA, Shirran, SL, Ajjan RA & Stewart, AJ 2025, ‘Quantitative proteomics identifies plasma protein alterations that assocuate with metabolic and thrombotic profile changes after bariatric surgery. ‘ Diabetes, Obesity and Metabolism, vol 27, 2647-2657.
Lu, J, Hierons, SJ, Arya, S, Fritzen, R, Polepalli, S, Khazaipoul, S, Stewart, AJ & Blindauer, CA 2025, ‘Properties of the major Zn2+-binding site on human alpha-fetoprotein, a potential foetal zinc carrier.‘ Chemical Communications, vol 61, 2099-2102.
Wu, D, Hierons, S, Polepalli, S, Gucwa, M, Fritzen, R, Markiewicz, M, Sabín, J, Minor, W, Murzyn, K, Blindauer, CA & Stewart, AJ 2024, ‘Targeted removal of the FA2 site on human albumin prevents fatty acid-mediated inhibition of Zn2+-binding. ‘ Journal of Lipid Research, vol 65, 100560.
Leal, KNS, da SIlva, ABS, Aragão, AZB, Ramos, CHI, Stewart, AJ & Arruda, MAZ 2024, ‘Optimizing the performance of single-cell ICP-MS for Fe and Zn determination in human umbilical vascular endothelial cells.‘ Microchemical Journal, vol 202, 110696.
Coverdale, JPC, Polepalli, S, Arruda, MAZ, Silva, ABS, Stewart AJ & Blindauer CA 2024 ‘Recent advances in metalloproteomics.‘ Biomolecules, vol 14, 104.
Wu, D, Gucwa, M, Czub, MP, Cooper, DR, Shabalin, IG, Fritzen, R, Arya, S, Schwarz-Linek, U, Blindauer, CA, Minor, W & Stewart, AJ 2023, ‘Structural and biochemical characterisation of Co2+-binding sites on serum albumins and their interplay with fatty acids.‘ Chemical Science, vol 14, 6244-6258.
Ackermann, K, Khazaipoul, S, Wort, JL, Sobczak, AIS, El Mkami, H, Stewart, AJ & Bode, BE 2023, ‘Investigating native metal ion binding sites in mammalian histidine-rich glycoprotein. ‘ Journal of the American Chemical Society, vol 145, 8064-8072.
Fritzen, R, Davies, A, Veenhuizen, M, Campbell, M, Pitt, SJ, Ajjan, RA & Stewart AJ 2023, ‘Magnesium deficiency and cardiometabolic disease.‘ Nutrients, vol 15, 2355.
Dorward, AM, Stewart, AJ & Pitt, SJ 2023, ‘The role of Zn2+ in shaping Ca2+dynamics in the heart.‘ Journal of General Physiology, vol 155, e202213206.
Guo, N, Minas, G, Synowsky, SA, Dunne, M, Ahmed, H, McShane, R, Bhardwaj, A, Donlon NE, Lorton, C, O’Sullivan, J., Reynolds, JV, Caie, P, Shirran, SL, Lynch, A, Stewart, AJ & Arya, S 2022 ‘Identification of plasma proteins associated with oesophageal cancer chemotherapeutic treatment outcomes using SWATH-MS. ‘ Journal of Proteomics, vol 266, 104684.
Arruda, MAZ, de Jesus, JR, Blindauer, CA & Stewart, AJ 2022, ‘Speciomics as a concept involving chemical speciation and omics. ‘ Journal of Proteomics, vol 263, 104615.
Czub, MP, Stewart, AJ, Shabalin, IG, Minor, W & 2022, ‘Organism specific differences in binding of ketoprofen to serum albumin.‘ International Union of Crystallography (IUCrJ) Journal, vol 9, 551-561.
Coverdale, JPC, van den Burgh, HA, Khazaipoul, S, Bridgewater, HE, Stewart, AJ & Blindauer, CA 2022, ‘Albumin-mediated extracellular zinc speciation drives cellular zinc uptake.‘ Chemical Communications, vol 58, 7384-7387.
Sobczak, AIS, Katundu, KG, Phoenix, F, Khazaipoul, S, Yu, R, Lampiao, F, Stefanowicz, F, Blindauer, CA, Pitt, SJ, Smith, TK, Ajjan, RA & Stewart, AJ 2021, ‘Albumin-mediated alteration of plasma zinc speciation by fatty acids modulates blood clotting in type-2 diabetes‘ Chemical Science, vol 12, 4079-4093.
Sobczak, AIS, Phoenix, F, Pitt, SJ, Ajjan, RA & Stewart, AJ 2020, ‘Reduced magnesium levels in type 1 diabetes associate with prothrombotic changes in fibrin clotting and fibrinolysis‘ Thrombosis and Haemostasis, vol 120, 243-252.
Wort, JL, Ackermann, K, Giannoulis, A, Stewart, AJ, Norman, DG & Bode BE 2019, ‘Submicromolar pulse dipolar EPR spectroscopy reveals increasing CuII-labelling of double-histidine motifs with lower temperature‘ Angewandte Chemie International Edition, vol 58, 11681-11685.
Arya, S, Wiatrek-Moumoulidis, D, Synowsky, SA, Shirran, SL, Botting, CH, Powis, SJ & Stewart, AJ 2019, ‘Quantitative proteomic changes in LPS-activated monocyte-derived dendritic cells: A SWATH-MS study‘ Scientific Reports, vol 9, 4343.
Bergen, AA, Arya, S, Koster, C., Pilgrim, MG, Wiatrek-Moumoulidis, D, van der Spek, P, Hauck, SM, Boon, CJF, Emri, E, Stewart, AJ & Lengyel I 2019, ‘On the origin of proteins in human drusen: The meet, greet and stick hypothesis‘ Progress in Retinal and Eye Research, vol 70, 55-84.
Martin, EM, Kondrat, FDL, Stewart, AJ, Scrivens, JH, Sadler, PJ & Blindauer, CA 2018, ‘Native electrospray mass spectrometry approaches to probe the interaction between zinc and an anti-angiogenic peptide from histidine-rich glycoprotein‘ Scientific Reports, vol 8, 8646.
Sobczak, AIS, Pitt, SJ & Stewart, AJ 2018, ‘Glycosaminoglycan neutralization in coagulation control‘ Arteriosclerosis, Thrombosis, and Vascular Biology, vol 38, 1258-1270.