scholarly journals Liposome-embedded heme with an oxygen-binding ability under physiological conditions.

1985 ◽  
Vol 42 (10) ◽  
pp. 685-688 ◽  
Author(s):  
Makoto YUASA ◽  
Yuichiro TANI ◽  
Hiroyuki NISHIDE ◽  
Eishun TSUCHIDA
Keyword(s):  
Oxygen Binding ◽  
Binding Ability ◽  
Physiological Conditions

scholarly journals Pentosan polysulfate increases affinity between ADAMTS-5 and TIMP-3 through formation of an electrostatically driven trimolecular complex

2012 ◽  
Vol 443 (1) ◽  
pp. 307-315 ◽  
Author(s):  
Linda Troeberg ◽  
Barbara Mulloy ◽  
Peter Ghosh ◽  
Meng-Huee Lee ◽  
Gillian Murphy ◽  
...  
Keyword(s):  
Sulfated Polysaccharide ◽  
Pentosan Polysulfate ◽  
Endogenous Inhibitor ◽  
Binding Ability ◽  
Physiological Conditions ◽  
Interaction Sites ◽  
High Affinity ◽  
Multiple Protein ◽  
Trimolecular Complex ◽  
Protein Interaction Sites

The semi-synthetic sulfated polysaccharide PPS (pentosan polysulfate) increases affinity between the aggrecan-degrading ADAMTSs (adamalysins with thrombospondin motifs) and their endogenous inhibitor, TIMP (tissue inhibitor of metalloproteinases)-3. In the present study we demonstrate that PPS mediates the formation of a high-affinity trimolecular complex with ADAMTS-5 and TIMP-3. A TIMP-3 mutant that lacks extracellular-matrix-binding ability was insensitive to this affinity increase, and truncated forms of ADAMTS-5 that lack the Sp (spacer) domain had reduced PPS-binding ability and sensitivity to the affinity increase. PPS molecules composed of 11 or more saccharide units were 100-fold more effective than those of eight saccharide units, indicating the involvement of extended or multiple protein-interaction sites. The formation of a high-affinity trimolecular complex was completely abolished in the presence of 0.4 M NaCl. These results suggest that PPS enhances the affinity between ADAMTS-5 and TIMP-3 by forming electrostatically driven trimolecular complexes under physiological conditions.

scholarly journals Zein/Bioactive Glass Coatings with Controlled Degradation of Magnesium under Physiological Conditions: Designed for Orthopedic Implants

Prosthesis ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 211-224 ◽  
Author(s):  
Muhammad Atiq Ur Rehman
Keyword(s):  
Bioactive Glass ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Orthopedic Implants ◽  
Open Circuit ◽  
Practical Application ◽  
Binding Ability ◽  
Physiological Conditions ◽  
Biomedical Device

Magnesium and its alloys are widely considered as temporary bio-implants owing to their mechanical properties and biocompatibility. However, the high corrosion rates and degradation in the physiological environment restrict the practical application of Mg as a biomedical device. Therefore, in this study, Zein/45S5 bioactive glass (BG) coatings were deposited via electrophoretic deposition (EPD) on pretreated pure magnesium (Mg) substrates, which controls the rapid degradation of magnesium. The set of EPD parameters was first optimized on stainless steel (SS) and then the optimum EPD parameters were applied to obtain zein/BG composite coatings on Mg substrates. The morphology of the obtained coatings was studied by scanning electron microscopy (SEM). SEM results showed that both zein and BG were successfully deposited on the surface of the Mg substrate. Electrochemical measurements consisting of open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization confirmed that the corrosion resistance of Mg improved after the deposition of zein/BG coatings. The in-vitro bioactivity study was carried out by immersing the zein/BG coatings in simulated body fluid for 3, 7, and 21 days. SEM, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy results elucidated that the hydroxyapatite layer developed after 21 days of immersion in SBF, which confirmed the bone binding ability of the coatings.

OXYGEN-BINDING AFFINITY OF LIPOSOMAL HEME UNDER SEMI PHYSIOLOGICAL CONDITIONS

1983 ◽  
Vol 12 (4) ◽  
pp. 473-476 ◽  
Author(s):  
Eishun Tsuchida ◽  
Hiroyuki Nishide ◽  
Makoto Yuasa ◽  
Mikiya Sekine
Keyword(s):  
Binding Affinity ◽  
Oxygen Binding ◽  
Physiological Conditions

scholarly journals Complexation induced fluorescence and acid–base properties of dapoxyl dye with γ-cyclodextrin: a drug-binding application using displacement assays

2015 ◽  
Vol 17 (24) ◽  
pp. 16015-16022 ◽  
Author(s):  
Kaushik Pal ◽  
Suman Mallick ◽  
Apurba L. Koner
Keyword(s):  
Drug Binding ◽  
Acid Base ◽  
Binding Ability ◽  
Physiological Conditions ◽  
Displacement Assays ◽  
Base Properties

The drug binding ability of γ-cyclodextrin in physiological conditions is evaluated experimentally and computationally via the dye displacement principle using dapoxyl dye.

scholarly journals Expression of cytoglobin and PGC-1α is high during tail tissue regeneration of the house gecko (Hemidactylus platyurus)

2019 ◽  
Author(s):  
Titta Novianti ◽  
Vetnizah Juniantito ◽  
Ahmad Aulia Jusuf ◽  
Evy Ayu Arida ◽  
Mohamad Sadikin ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Mitochondrial Biogenesis ◽  
Energy Production ◽  
Regeneration Process ◽  
Peroxisome Proliferator ◽  
Oxygen Binding ◽  
Binding Ability ◽  
Peroxisome Proliferator Activated Receptor ◽  
Lower Expression

Abstract Abstract Background Tissue regeneration is a process that need a high demand of oxygen and energy supply. Cytoglobin (Cygb) is a hexacoordinate globin superfamily that possesses strong oxygen-binding ability. Cygb also has a role in preventing cells from oxidative stress and carrying oxygen into the mitochondria. The production of energy for regeneration is associated with mitochondria, especially mitochondrial biogenesis. The peroxisome proliferator-activated receptor gamma coactivator (PGC-1α) is aprotein that plays an important role in regulating mitochondrial biogenesis. The house gecko (Hemidactylus platyurus) is a reptile with high ability for tissue regeneration in its tail. The house gecko was selected as the animal model for this research to analyse the role of Cygb which is associated with oxygen supply and PGC-1α that is related to energy production in tissue regeneration. Results The curve for the tail growth showed three different phases. Cygb mRNA was highly expressed during tissue regeneration. PGC-1α mRNA was expressed earlier than Cygb, with a lower expression but still higher than the control. Conclusions During the tail tissue regeneration process of the house gecko, the expression of Cygb and PGC-1α were dynamic and relatively higher than their expression observed in the control. Cygb and PGC-1α were suspected to have a significant role in the tissue regeneration process.

scholarly journals Dynamics of camel and human hemoglobin revealed by molecular simulations

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Amanat Ali ◽  
Soja Saghar Soman ◽  
Ranjit Vijayan
Keyword(s):  
Physiological Stress ◽  
Experimental Studies ◽  
Oxygen Binding ◽  
Human Hemoglobin ◽  
Heme Group ◽  
Structural Variations ◽  
Physiological Conditions ◽  
Cofactor Binding ◽  
Dynamics Simulations ◽  
T State

AbstractHemoglobin is one of the most widely studied proteins genetically, biochemically, and structurally. It is an oxygen carrying tetrameric protein that imparts the characteristic red color to blood. Each chain of hemoglobin harbors a heme group embedded in a hydrophobic pocket. Several studies have investigated structural variations present in mammalian hemoglobin and their functional implications. However, camel hemoglobin has not been thoroughly explored, especially from a structural perspective. Importantly, very little is known about how the heme group interacts with hemoglobin under varying conditions of osmolarity and temperature. Several experimental studies have indicated that the tense (T) state is more stable than the relaxed (R) state of hemoglobin under normal physiological conditions. Despite the fact that R state is less stable than the T state, no extensive structural dynamics studies have been performed to investigate global quaternary transitions of R state hemoglobin under normal physiological conditions. To evaluate this, several 500 ns all-atom molecular dynamics simulations were performed to get a deeper understanding of how camel hemoglobin behaves under stress, which it is normally exposed to, when compared to human hemoglobin. Notably, camel hemoglobin was more stable under physiological stress when compared to human hemoglobin. Additionally, when compared to camel hemoglobin, cofactor-binding regions of hemoglobin also exhibited more fluctuations in human hemoglobin under the conditions studied. Several differences were observed between the residues of camel and human hemoglobin that interacted with heme. Importantly, distal residues His58 of α hemoglobin and His63 of β hemoglobin formed more sustained interactions, especially at higher temperatures, in camel hemoglobin. These residues are important for oxygen binding to hemoglobin. Thus, this work provides insights into how camel and human hemoglobin differ in their interactions under stress.

scholarly journals Dual conformational recognition by Z-DNA binding protein is important for the B–Z transition process

2020 ◽  
Vol 48 (22) ◽  
pp. 12957-12971
Author(s):  
Chaehee Park ◽  
Xu Zheng ◽  
Chan Yang Park ◽  
Jeesoo Kim ◽  
Seul Ki Lee ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Protein ◽  
Transition Process ◽  
Dna Binding Protein ◽  
Binding Ability ◽  
Physiological Conditions ◽  
Transition Activities ◽  
Left Handed ◽  
Z Dna ◽  
Insight Into

Abstract Left-handed Z-DNA is radically different from the most common right-handed B-DNA and can be stabilized by interactions with the Zα domain, which is found in a group of proteins, such as human ADAR1 and viral E3L proteins. It is well-known that most Zα domains bind to Z-DNA in a conformation-specific manner and induce rapid B–Z transition in physiological conditions. Although many structural and biochemical studies have identified the detailed interactions between the Zα domain and Z-DNA, little is known about the molecular basis of the B–Z transition process. In this study, we successfully converted the B–Z transition-defective Zα domain, vvZαE3L, into a B–Z converter by improving B-DNA binding ability, suggesting that B-DNA binding is involved in the B–Z transition. In addition, we engineered the canonical B-DNA binding protein GH5 into a Zα-like protein having both Z-DNA binding and B–Z transition activities by introducing Z-DNA interacting residues. Crystal structures of these mutants of vvZαE3L and GH5 complexed with Z-DNA confirmed the significance of conserved Z-DNA binding interactions. Altogether, our results provide molecular insight into how Zα domains obtain unusual conformational specificity and induce the B–Z transition.

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