Alan Strunga

Scopus Publications

Concentration-dependent dimerization of staphylokinase variants with engineered surface charges
Michal Nemergut, Monika Štulajterová, Rostislav Škrabana, Andrej Hovan, L'uboš Ambro, et al.
Protein Science, 2026
Staphylokinase (SAK) is a promising third‐generation thrombolytic protein, but its clinical potential is limited by immunogenicity and stability concerns. The conformational and colloidal stabilities of four SAK variants—SAK 42D, SAK STAR, and their non‐immunogenic derivatives SAK 42D 3A and SAK STAR 3A—were evaluated using differential scanning calorimetry (DSC), dynamic light scattering (DLS), and aggregation kinetics assays. DSC analyses revealed that thermal denaturation of all variants proceeds via two consecutive irreversible steps, with transition parameters strongly dependent on scan rate and protein concentration. SAK STAR variants exhibited markedly exothermic first transitions and reduced scan rate dependence, suggesting stabilization of intermediate states and suppression of aggregation. In contrast, SAK 42D variants exhibited endothermic or weakly exothermic first transitions and a higher aggregation propensity, correlating with reduced conformational stability and formation of less stable dimers. Colloidal stability tests showed that SAK STAR and SAK STAR 3A remained largely aggregation‐resistant, whereas SAK 42D and SAK 42D 3A aggregated rapidly at elevated temperatures (>51°C and >38°C, respectively), following apparent second‐order kinetics. DLS confirmed concentration‐dependent dimerization in all variants, with SAK 42D 3A displaying pronounced polydispersity and instability. We could rationalize this behavior in the context of engineered surface charges. Our results demonstrate that SAK variant stability is shaped by a complex interplay between primary sequence, dimerization behavior, and aggregation propensity, guiding the design of clinically viable thrombolytic agents and their formulations.
Thrombolytic proteins profiling: High-throughput activity, selectivity, and resistance assays
Martin Toul, Alan Strunga, Jiri Damborsky, Zbynek Prokop
FEBS Open Bio, 2026
Cardiovascular diseases, including thrombotic events such as ischemic stroke, pulmonary embolism, and myocardial infarction, are among the leading causes of morbidity and disability worldwide. The application of clot‐dissolving thrombolytic enzymes is a cost‐effective therapeutic intervention for these life‐threatening conditions. However, the effectiveness and safety profiles of current drugs are suboptimal, necessitating the discovery of new medicines or the engineering and enhancement of the existing ones. Here, we present a set of optimized biochemical protocols that allow robust screening and the therapeutic potential assessment of thrombolytic biomolecules. The assays provide information on multiple characteristics such as enzymatic activity, fibrinolysis rate, fibrin and fibrinogen stimulation, fibrin selectivity, clot binding affinity, and inhibition resistance. Such detailed characterization enables a rapid and reliable evaluation of candidate effectiveness and provides an indication of biological half‐life, associated bleeding complications, and other side effects. We demonstrate the credibility of the methodology by applying it to the two most widely used thrombolytic drugs: alteplase (Activase®/Actilyse®) and tenecteplase (Metalyse®/TNKase®). Consistent with previous studies, tenecteplase exhibited increased fibrin selectivity and inhibition resistance, which explains its extended half‐life. Our findings reinforce the growing consensus that tenecteplase may be a superior alternative to alteplase for thrombolytic treatment.
Assessing the impact of His-tags on activity and stability of staphylokinase variants
Monika Štulajterová, Ľuboš Ambro, Dagmar Sedláková, Michal Nemergut, Pavel Kohout, et al.
International Journal of Biological Macromolecules, 2025
Experimental determination of the heat transfer coefficients of shell-and-tube heat exchangers with different hollow fiber arrangements
Alan Strunga, Tereza Kroulíková, Erik Bartuli, Miroslav Raudenský
Journal of Thermal Analysis and Calorimetry, 2022
Fully polymeric distillation unit based on polypropylene hollow fibers
Tereza Kůdelová, Erik Bartuli, Alan Strunga, Jiří Hvožďa, Miroslav Dohnal
Polymers, 2021
Access to pure water is a very topical issue today. Desalination represents a promising way of obtaining drinking water in areas of shortage. Currently, efforts are being made to replace the metal components of existing desalination units due to the high corrosivity of sea water. Another requirement is easy transportation and assembly. The presented solution combines two types of polymeric hollow fibers that are used to create the distillation unit. Porous polypropylene hollow fiber membranes have been used as an active surface for mass transfer in the distillation unit, while non-porous thermal polypropylene hollow fibers have been employed in the condenser. The large active area to volume ratio of the hollow fiber module improves the efficiency of both units. Hot water is pumped inside the membranes in the distillation unit. Evaporation is first observed at a temperature gradient of 10 °C. The water vapor flows through the tunnel to the condenser where cold water runs inside the fibers. The temperature gradient causes condensation of the vapor, and the condensate is collected. The article presents data for hot water at temperatures of 55, 60, and 65 °C. Optimization of the membrane module is evaluated and presented.