Ligandability Assessment of IL-1β by Integrated Hit Identification Approaches

Human interleukin-1β (IL-1β) is a pro-inflammatory cytokine that plays a critical role in the regulation of the immune response and the development of various inflammatory diseases. In this publication, we disclose our efforts toward the discovery of IL-1β binders that interfere with IL-1β signaling. To this end, several technologies were used in parallel, including fragment-based screening (FBS), DNA-encoded library (DEL) technology, peptide discovery platform (PDP), and virtual screening. The utilization of distinct technologies resulted in the identification of new chemical entities exploiting three different sites on IL-1β, all of them also inhibiting the interaction with the IL-1R1 receptor. Moreover, we identified lysine 103 of IL-1β as a target residue suitable for the development of covalent, low-molecular-weight IL-1β antagonists.

Freeze-Induced Phase Transition and Local Pressure in a Phospholipid/Water System: Novel Insights Were Obtained from a Time/Temperature Resolved Synchrotron X-ray Diffraction Study

Water-to-ice transformation results in a 10% increase in volume, which can have a significant impact on biopharmaceuticals during freeze-thaw cycles due to the mechanical stresses imparted by the growing ice crystals. Whether these stresses would contribute to the destabilization of biopharmaceuticals depends on both the magnitude of the stress and sensitivity of a particular system to pressure and sheer stresses. To address the gap of the "magnitude" question, a phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), is evaluated as a probe to detect and quantify the freeze-induced pressure. DPPC can form several phases under elevated pressure, and therefore, the detection of a high-pressure DPPC phase during freezing would be indicative of a freeze-induced pressure increase. In this study, the phase behavior of DPPC/water suspensions, which also contain the ice nucleation agent silver iodide, is monitored by synchrotron small/wide-angle X-ray scattering during the freeze-thaw transition. Cooling the suspensions leads to heterogeneous ice nucleation at approximately -7 °C, followed by a phase transition of DPPC between -11 and -40 °C. In this temperature range, the initial gel phase of DPPC, Lβ', gradually converts to a second phase, tentatively identified as a high-pressure Gel III phase. The Lβ'-to-Gel III phase transition continues during an isothermal hold at -40 °C; a second (homogeneous) ice nucleation event of water confined in the interlamellar space is detected by differential scanning calorimetry (DSC) at the same temperature. The extent of the phase transition depends on the DPPC concentration, with a lower DPPC concentration (and therefore a higher ice fraction), resulting in a higher degree of Lβ'-to-Gel III conversion. By comparing the data from this study with the literature data on the pressure/temperature Lβ'/Gel III phase boundary and the lamellar lattice constant of the Lβ' phase, the freeze-induced pressure is estimated to be approximately 0.2-2.6 kbar. The study introduces DPPC as a probe to detect a pressure increase during freezing, therefore addressing the gap between a theoretical possibility of protein destabilization by freeze-induced pressure and the current lack of methods to detect freeze-induced pressure. In addition, the observation of a freeze-induced phase transition in a phospholipid can improve the mechanistic understanding of factors that could disrupt the structure of lipid-based biopharmaceuticals, such as liposomes and mRNA vaccines, during freezing and thawing.

Mannitol Crystallization at Sub-Zero Temperatures: Time/Temperature-Resolved Synchrotron X-ray Diffraction Study and the Phase Diagram

Mannitol, a common pharmaceutical ingredient, exhibits complex polymorphism even in simple binary mannitol/water mixtures, with four crystalline forms observed. In this investigation, time/temperature-resolved synchrotron X-ray diffraction measurements are performed during freezing and thawing of mannitol/water mixtures. Mannitol crystallization depends strongly on the cooling rate and is initiated during cooling, if the cooling rate is lower than the critical cooling rate; otherwise, mannitol remains amorphous during freezing and crystallizes during subsequent heating above -30 °C. A temperature-composition phase diagram is constructed, reflecting eutectic and peritectic points and lower-temperature equilibria involving mannitol hemihydrate, hexagonal ice, and β-mannitol. Comparison of the experimental data with the phase diagram reveals that the mannitol crystallization behavior does not follow the equilibrium but appears to obey the Ostwald crystallization rule. Novel insights on equilibrium and kinetics phase relationships in mannitol/water systems could lead to improved formulations and manufacturing processes for pharmaceuticals and biopharmaceuticals.

Structural investigation and compression of a co-crystal of indomethacin and saccharin

Indomethacin : saccharin cocrystal has been studied under high pressure conditions and the amide interactions compared with previous high pressure studies.

Carbon dioxide binary crystals via the thermal decomposition of RDX at high pressure

A carbon dioxide and nitrous oxide solid solution has been captured in a diamond anvil cell following the thermal decomposition of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) at high temperatures and pressures. This is the first time a carbon dioxide binary solid has been observed at high pressure. This observation has stimulated low temperature crystallographic studies of this binary system using recently developed gas absorption apparatus and computational modelling.

The ecstasy and the agony; compression studies of 3,4-methylenedioxymethamphetamine (MDMA)

MDMA (3,4-methylenedioxymethamphetamine) is a Class A substance that is usually found in a tableted form. It is only observed in one orthorhombic polymorph under ambient conditions. It shows slight positional disorder around the methlyenedioxy ring which persists during compression up to 6.66 GPa. The crystal quality deteriorates above 6.66 GPa where the hydrostatic limit of the pressure-transmitting medium is exceeded. The structure undergoes anisotropic compression with thea-axis compressing the greatest (12%cf.4 and 10% for theb- andc-axes, respectively). This is due to the pattern of the hydrogen bonding which acts like a spring and allows the compression along this direction.