Osmotic stress studies of G-protein-coupled receptor rhodopsin activation
Biophys Chem. 2023 Sep 26;304:107112. doi: 10.1016/j.bpc.2023.107112. Online ahead of print.ABSTRACTWe summarize and critically review osmotic stress studies of the G-protein-coupled receptor rhodopsin. Although small amounts of structural water are present in these receptors, the effect of bulk water on their function remains uncertain. Studies of the influences of osmotic stress on the GPCR archetype rhodopsin have given insights into the functional role of water in receptor activation. Experimental work has discovered that osmolytes shift the metarhodopsin equilibrium after photoactivation, either to the active or inact...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Andrey V Struts Alexander V Barmasov Steven D E Fried Kushani S K Hewage Suchithranga M D C Perera Michael F Brown Source Type: research
Pomegranate peel, chokeberry leaves and Ironwort extract as novel natural inhibitors of amylin aggregation and cellular toxicity in pancreatic β cells
Biophys Chem. 2023 Oct 31;304:107130. doi: 10.1016/j.bpc.2023.107130. Online ahead of print.ABSTRACTImpeding or reducing human amylin aggregation and/or its toxicity can be key to preventing pancreatic islet amyloidosis and β-cell loss in patients with Type 2 Diabetes Mellitus (T2DM). Here, Punica granatum (pomegranate) peel, Sideritis raeseri (ironwort) and Aronia melanocarpa (chokeberry) leaf extracts, were tested for their novel anti-aggregative and antitoxic properties in human amylin (hIAPP) treated rat pancreatic insulinoma (INS) cells. The protein aggregation (Th-T) assay revealed an inhibitory trend of all three p...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Achanta Rishisree Brayer Mallory Karnaukhova Elena Jankovic Teodora Zduni ć Gordana Šavikin Katarina Jeremic Aleksandar Source Type: research
Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds
Biophys Chem. 2023 Oct 29;304:107127. doi: 10.1016/j.bpc.2023.107127. Online ahead of print.ABSTRACTThe preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50-100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs ...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Aristeidis Papagiannopoulos Aggeliki Sklapani Nikolaos Spiliopoulos Source Type: research
Osmotic stress studies of G-protein-coupled receptor rhodopsin activation
Biophys Chem. 2023 Sep 26;304:107112. doi: 10.1016/j.bpc.2023.107112. Online ahead of print.ABSTRACTWe summarize and critically review osmotic stress studies of the G-protein-coupled receptor rhodopsin. Although small amounts of structural water are present in these receptors, the effect of bulk water on their function remains uncertain. Studies of the influences of osmotic stress on the GPCR archetype rhodopsin have given insights into the functional role of water in receptor activation. Experimental work has discovered that osmolytes shift the metarhodopsin equilibrium after photoactivation, either to the active or inact...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Andrey V Struts Alexander V Barmasov Steven D E Fried Kushani S K Hewage Suchithranga M D C Perera Michael F Brown Source Type: research
Pomegranate peel, chokeberry leaves and Ironwort extract as novel natural inhibitors of amylin aggregation and cellular toxicity in pancreatic β cells
Biophys Chem. 2023 Oct 31;304:107130. doi: 10.1016/j.bpc.2023.107130. Online ahead of print.ABSTRACTImpeding or reducing human amylin aggregation and/or its toxicity can be key to preventing pancreatic islet amyloidosis and β-cell loss in patients with Type 2 Diabetes Mellitus (T2DM). Here, Punica granatum (pomegranate) peel, Sideritis raeseri (ironwort) and Aronia melanocarpa (chokeberry) leaf extracts, were tested for their novel anti-aggregative and antitoxic properties in human amylin (hIAPP) treated rat pancreatic insulinoma (INS) cells. The protein aggregation (Th-T) assay revealed an inhibitory trend of all three p...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Achanta Rishisree Brayer Mallory Karnaukhova Elena Jankovic Teodora Zduni ć Gordana Šavikin Katarina Jeremic Aleksandar Source Type: research
Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds
Biophys Chem. 2023 Oct 29;304:107127. doi: 10.1016/j.bpc.2023.107127. Online ahead of print.ABSTRACTThe preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50-100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs ...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Aristeidis Papagiannopoulos Aggeliki Sklapani Nikolaos Spiliopoulos Source Type: research
Osmotic stress studies of G-protein-coupled receptor rhodopsin activation
Biophys Chem. 2023 Sep 26;304:107112. doi: 10.1016/j.bpc.2023.107112. Online ahead of print.ABSTRACTWe summarize and critically review osmotic stress studies of the G-protein-coupled receptor rhodopsin. Although small amounts of structural water are present in these receptors, the effect of bulk water on their function remains uncertain. Studies of the influences of osmotic stress on the GPCR archetype rhodopsin have given insights into the functional role of water in receptor activation. Experimental work has discovered that osmolytes shift the metarhodopsin equilibrium after photoactivation, either to the active or inact...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Andrey V Struts Alexander V Barmasov Steven D E Fried Kushani S K Hewage Suchithranga M D C Perera Michael F Brown Source Type: research
Pomegranate peel, chokeberry leaves and Ironwort extract as novel natural inhibitors of amylin aggregation and cellular toxicity in pancreatic β cells
Biophys Chem. 2023 Oct 31;304:107130. doi: 10.1016/j.bpc.2023.107130. Online ahead of print.ABSTRACTImpeding or reducing human amylin aggregation and/or its toxicity can be key to preventing pancreatic islet amyloidosis and β-cell loss in patients with Type 2 Diabetes Mellitus (T2DM). Here, Punica granatum (pomegranate) peel, Sideritis raeseri (ironwort) and Aronia melanocarpa (chokeberry) leaf extracts, were tested for their novel anti-aggregative and antitoxic properties in human amylin (hIAPP) treated rat pancreatic insulinoma (INS) cells. The protein aggregation (Th-T) assay revealed an inhibitory trend of all three p...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Achanta Rishisree Brayer Mallory Karnaukhova Elena Jankovic Teodora Zduni ć Gordana Šavikin Katarina Jeremic Aleksandar Source Type: research
Thermally stabilized chondroitin sulfate-hemoglobin nanoparticles and their interaction with bioactive compounds
Biophys Chem. 2023 Oct 29;304:107127. doi: 10.1016/j.bpc.2023.107127. Online ahead of print.ABSTRACTThe preparation of nanoparticles (NPs) based on hemoglobin (Hb) with a fully biocompatible methodology is presented. The spontaneous formation of electrostatic complexes of Hb with chondroitin sulfate (CS) at pH 4 in the polysaccharide/protein mass ratio regime where charge neutrality is met leads to spherical nanostructures with monomodal hydrodynamic radii distribution in the range of 50-100 nm. The integrity of the electrostatic complexes is disturbed at pH 7 as the net electric charge of Hb is very low. Treating the NPs ...
Source: Biophysical Chemistry - November 12, 2023 Category: Chemistry Authors: Aristeidis Papagiannopoulos Aggeliki Sklapani Nikolaos Spiliopoulos Source Type: research
Palmitoylation modifies transmembrane adaptor protein PAG for ordered lipid environment: A molecular dynamics simulation study
Biophys Chem. 2023 Oct 13;304:107124. doi: 10.1016/j.bpc.2023.107124. Online ahead of print.ABSTRACTWe employed all-atom MD simulations to investigate the impact of palmitoylation on the PAG transmembrane peptide within various lipid environments, including the less explored boundary region separating lipid-ordered (Lo) and lipid-disordered (Ld) membrane phases. We found that palmitoylation of the peptide reduces its impact on membrane thickness, particularly within the Lo and boundary environments. Despite their hydrophobic nature, the palmitoyl chains on the peptide did not significantly affect the hydration of the surro...
Source: Biophysical Chemistry - November 11, 2023 Category: Chemistry Authors: Maria Chiara Saija Ad éla Melcrová Wojciech Pajerski Itay Schachter Matti Javanainen Marek Cebecauer Lukasz Cwiklik Source Type: research
Palmitoylation modifies transmembrane adaptor protein PAG for ordered lipid environment: A molecular dynamics simulation study
Biophys Chem. 2023 Oct 13;304:107124. doi: 10.1016/j.bpc.2023.107124. Online ahead of print.ABSTRACTWe employed all-atom MD simulations to investigate the impact of palmitoylation on the PAG transmembrane peptide within various lipid environments, including the less explored boundary region separating lipid-ordered (Lo) and lipid-disordered (Ld) membrane phases. We found that palmitoylation of the peptide reduces its impact on membrane thickness, particularly within the Lo and boundary environments. Despite their hydrophobic nature, the palmitoyl chains on the peptide did not significantly affect the hydration of the surro...
Source: Biophysical Chemistry - November 11, 2023 Category: Chemistry Authors: Maria Chiara Saija Ad éla Melcrová Wojciech Pajerski Itay Schachter Matti Javanainen Marek Cebecauer Lukasz Cwiklik Source Type: research
TPE conjugated islet amyloid polypeptide probe for detection of peptide oligomers
In this study, we successfully grafted an aggregation-induced emission molecule, tetraphenylethylene (TPE), at the N-terminus of IAPP. By mixing a small amount of TPE-labeled IAPP with unlabeled IAPP, we were able to detect an increase in TPE fluorescence during the nucleation phase of IAPP aggregation in vitro. It may enable real-time monitoring of IAPP oligomer formation and is further applied in the diagnosis of T2D.PMID:37948788 | DOI:10.1016/j.bpc.2023.107129 (Source: Biophysical Chemistry)
Source: Biophysical Chemistry - November 10, 2023 Category: Chemistry Authors: Hsiao-Chieh Tsai Ching-Hong Huang Ling-Hsien Tu Source Type: research
TPE conjugated islet amyloid polypeptide probe for detection of peptide oligomers
In this study, we successfully grafted an aggregation-induced emission molecule, tetraphenylethylene (TPE), at the N-terminus of IAPP. By mixing a small amount of TPE-labeled IAPP with unlabeled IAPP, we were able to detect an increase in TPE fluorescence during the nucleation phase of IAPP aggregation in vitro. It may enable real-time monitoring of IAPP oligomer formation and is further applied in the diagnosis of T2D.PMID:37948788 | DOI:10.1016/j.bpc.2023.107129 (Source: Biophysical Chemistry)
Source: Biophysical Chemistry - November 10, 2023 Category: Chemistry Authors: Hsiao-Chieh Tsai Ching-Hong Huang Ling-Hsien Tu Source Type: research
Simulated pressure changes in LacI suggest a link between hydration and functional conformational changes
Biophys Chem. 2023 Oct 26;304:107126. doi: 10.1016/j.bpc.2023.107126. Online ahead of print.ABSTRACTThe functions of many proteins are associated with interconversions among conformational substates. However, these substates can be difficult to measure experimentally, and determining contributions from hydration changes can be especially difficult. Here, we assessed the use of pressure perturbations to sample the substates accessible to the Escherichia coli lactose repressor protein (LacI) in various liganded forms. In the presence of DNA, the regulatory domain of LacI adopts an Open conformation that, in the absence of DN...
Source: Biophysical Chemistry - November 4, 2023 Category: Chemistry Authors: Nilusha L Kariyawasam Elizabeth A Ploetz Liskin Swint-Kruse Paul E Smith Source Type: research
Simulated pressure changes in LacI suggest a link between hydration and functional conformational changes
Biophys Chem. 2023 Oct 26;304:107126. doi: 10.1016/j.bpc.2023.107126. Online ahead of print.ABSTRACTThe functions of many proteins are associated with interconversions among conformational substates. However, these substates can be difficult to measure experimentally, and determining contributions from hydration changes can be especially difficult. Here, we assessed the use of pressure perturbations to sample the substates accessible to the Escherichia coli lactose repressor protein (LacI) in various liganded forms. In the presence of DNA, the regulatory domain of LacI adopts an Open conformation that, in the absence of DN...
Source: Biophysical Chemistry - November 4, 2023 Category: Chemistry Authors: Nilusha L Kariyawasam Elizabeth A Ploetz Liskin Swint-Kruse Paul E Smith Source Type: research
