Structure Of Hb Research Articles

On the Biophysical Investigation of Sulfamethazine‐Hemoglobin Binding and the Resulting Adverse Effects of Antibiotics

AbstractBinding of the well‐known antibiotic drug sulfamethazine (SMZ) with tetrameric heme protein, hemoglobin (Hb), was studied using spectroscopic, calorimetric and molecular docking techniques. SMZ belongs to the sulfonamide group of medicines with versatile applications. Nevertheless, it can be biologically harmful if used in excess or in an uncontrolled manner. The binding induced absorbance and fluorescence data indicated a ground state complex formation between the drug and the protein with 1 : 1 stoichiometry. Drug induced conformational perturbation of Hb structure was investigated with circular dichroism and synchronous fluorescence. The binding constant obtained from spectroscopy was in the order of 104 M−1which was further confirmed by isothermal titration calorimetry. This may be higher compared to that of the oxygenation in Hb; thus SMZ binding can subsequently interrupt the oxygen transporting property of this iron protein. FRET analysis showed that the distance between SMZ and Hb is ∼3.75 nm, which is suitable for an effective binding. The MD simulation substantiated the mode and site of binding by confirming the factors contributing to the binding energy. It shows that SMZ binds to the central cavity close to subunit α 1‐helix of Hb. Residues around the drug forms hydrogen bonding and increases hydrophobicity to stabilize the SMZ−Hb complex. The binding interaction appears to be dominated by H‐bond formation and electrostatic and hydrophobic forces. This is in agreement with the thermodynamic analyses and contributes to the binding energy.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

Counselling Needs of Sickle-Cell Anaemia Adolescents in Ekiti State, Nigeria.

Sickle-cell disease is an autosomal recessive genetic disorder of hemoglobin (Hb) structure and the most common of the hemoglobinopathies. Hence, this study investigated counseling needs of sickle-cell anaemia adolescents in Ekiti State. Descriptive survey design was adopted for this study. Purposive sampling technique was adopted to draw a total of 121 respondents. A questionnaire was used to collect data for the study. Mean and rank order were used to answer the research question while chi-square and Analysis of Variance (ANOVA) were used to test the hypotheses at 0.05 level of significance. The findings revealed that counselling needs of adolescents with sickle-cell anaemia include counsellors are expected to encourage adolescents with sickle-cell anaemia to have confidence in self among others. The findings also revealed that there was a significant difference in the counselling needs of adolescents with sickle-cell anaemia based on gender while there was no significant difference in the counselling needs of adolescents with sickle-cell anaemia based on religion. The counselling needs of adolescents with sickle-cell anaemia include adolescents with sickle-cell anaemia easily comprehend the counselling therapy of counsellor among others. It was recommended that Government should offer standard health care for all adolescents with Sickle-cell disease.

Conformational changes of β-thalassemia major hemoglobin and oxidative status of plasma after in vitro exposure to extremely low-frequency electromagnetic fields: An artificial neural network analysis

ABSTRACT Electromagnetic fields (EMF) can generate reactive oxygen species and induce oxidative modifications. We investigated the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on oxidative status of plasma and erythrocytes in β-thalassemia major patients and design artificial neural networks (ANN) for evaluating the oxyHb concentration. Blood samples were obtained from age and sex-matched healthy donors (n = 12) and major β-thalassemia patients (n = 12) and subjected to 0.5 and 1 mT and 50 Hz of EMF. Plasma oxidative status was estimated after 1 and 2 h exposure to ELE-EMF. Structural changes of plasma proteins were investigated by Native PAGE and SDS-PAGE. Moreover; multilayer perceptron (MLP) method was applied for designing a feed forward ANN model to predict the impact of these oxidative and antioxidative parameters on oxyHb concentration. Two hour exposure to ELF-EMF induced significant oxidative changes on major β-thalassemia samplesElectrophoretic profiles showed two high molecular weight (HMW) protein aggregates in plasma samples from healthy donors and major β-thalassemia patients. According to our ANN design, the main predictors of oxyHb concentration were optical density of Hb at 542, 340, 569, 630, 577, and 420 nm and metHb and hemichrome (HC) concentration. Accuracy of the proposed ANN model was shown by predicted by observed chart (y = 1.3 + 0.96x, R2 = 0.942), sum of squares errors (SSR), and relative errors (RE). Our results showed the detailed effects of ELF-EMF on Hb structure and oxidative balance of plasma in major β-thalassemia patients and significance of ANN analysis during normal and pathologic conditions.

Highlighting the Importance of Water Alkalinity Using Phosphate Buffer Diluted With Deionized, Double Distilled and Tap Water, in Lowering Oxidation Effects on Human Hemoglobin Ozonated at High Ozone Concentrations in vitro.

In autohemotherapy, it is important to find a way to lower the effects of oxidation, especially at high concentrations of ozone. One of the parameters, other than ozone concentration, which can have a significant effect on the stability and rate of decomposition of ozone at high concentrations, is the presence of ions in water. A number of spectroscopic techniques including intrinsic fluorescence, circular dichroism and UV–VIS were used as well as SDS-PAGE, Native-PAGE dynamic light scattering and water ion analysis, in order to investigate the effects of two relatively high concentrations of ozone on purified human hemoglobin (Hb) in phosphate buffer and diluted versions with deionized, double distilled and tap water in vitro. Purified human Hb and not whole blood human Hb was used in this study, since the addition of water to the whole blood would have caused the RBCs to lyse, affecting the purification of Hb for further analysis. Therefore, using purified Hb, it was possible to investigate the effects of dilution of 50 mM phosphate buffer to 10 mM phosphate buffer with different water types including non-ion containing deionized and double distilled water as well as ion-containing tap water, when ozonated at 55 and 80 μg/ml ozone. The fundamental changes in the secondary and tertiary structures of Hb were seen to be related to non-ozonated Hb samples diluted with deionized and double distilled waters, respectively. Generally, Hb oligomerization was more likely to occur at the higher concentration of ozone (80 μg/ml) and in samples where phosphate buffer was diluted with non-ion containing deionized and double distilled waters and not the ion-containing tap water. This could be explained by the presence of water alkalinity or bicarbonate ions in tap water, which can scavenge free radicals and reduce Hb oxidation/oligomerization. Therefore, it was concluded that Hb could best withstand high concentrations of ozone in the presence of the undiluted 50 mM phosphate buffer followed by phosphate buffer diluted with tap water, containing bicarbonate ions.

Irreversible alterations in the hemoglobin structure affect oxygen binding in human packed red blood cells

The ability of hemoglobin (Hb) to transport respiratory gases is directly linked to its quaternary structure properties and reversible changes between T (tense) and R (relax) state. In this study we demonstrated that packed red blood cells (pRBCs) storage resulted in a gradual increase in the irreversible changes in the secondary and quaternary structures of Hb, with subsequent impairment of the T↔R transition. Such alteration was associated with the presence of irreversibly settled in the relaxed form, quaternary structure of Hb, which we termed R′. On the secondary structure level, disordered protein organization involved formation of β-sheets and a decrease in α-helices related to the aggregation process stabilized by strong intermolecular hydrogen bonding. Compensatory changes in RBCs metabolism launched to preserve reductive microenvironment were disclosed as an activation of nicotinamide adenine dinucleotide phosphate (NADPH) production and increased reduced to oxidized glutathione (GSH/GSSG) ratio. For the first time we showed the relationship between secondary structure changes and the occurrence of newly discovered R′, which through an artificial increase in oxyhemoglobin level altered Hb ability to bind and release oxygen.

Molecular spectrum of α-thalassemia mutations in Erbil province of Iraqi Kurdistan.

α-Thalassemia is a globally prevalent genetic disorder of hemoglobin (Hb) structure where the rate of α-globin chain synthesis is reduced or absent based on the underlying α-globin mutation(s). This study aimed to define the spectrum of α-globin gene mutations and assess their relative frequency within a group of α-thalassemia carriers. A total of 96 young subjects with unexplained hypochromia and microcytosis were recruited. They were referred from the premarital hemoglobinopathy screening and genetic counseling center in Erbil. All subjects were genetically tested for 21 common α-globin gene mutations using multiplex PCR and reverse hybridization. Six different α-globin gene mutations and nine different genotypes were detected in 84 carrier subjects. Their mean Hb was 12.9 (± 1.29) g/dL, of whom 49 subjects (58.3%) had a normal Hb level. The two most frequently encountered mutations were -α3.7 deletion (62.86%) and α2-5nt mutation (20%). Deletions were encountered in 71.43% of the mutated alleles. The most commonly observed genotype was -α3.7/αα (46.43%), followed by -α3.7/-α3.7 and α-5ntα/αα genotypes (10.72% each). Carriers of αpoly-A1α/αα and -α3.7/-α-5ntα genotypes showed significantly lower Hb, mean cell volume, and mean cell Hb values comparing to carriers of most other genotypes. In our population, the spectrum of α-globin mutations was confined to a limited number of mutations with deletions being mostly observed.

Effect of marinating ingredients on temperature-induced denaturation of hemoglobin and its relation to red blood spot formation in cooked chicken breast.

Red blood spot (RBS) commonly found in cooked chicken breast has caused severe economic loss as it is perceived as a sign of undercooked product. The objectives of this study were to investigate the cause of RBS as related to common ingredients used in marination, based on both chicken breast and isolated chicken hemoglobin (Hb) models. The effect of sodium chloride (NaCl), sodium tripolyphosphate (STPP), and glucose on thermal denaturation of Hb was investigated along with the extent of RBS formation in cooked marinated chicken breast. After vacuum tumbling for 65min and subsequent storage at 4°C for 20 hr, STPP and glucose were not absorbed into the center of chicken breast. However, Na+ was absorbed after 12 hr storage. The denaturation temperature (Td ) of isolated chicken Hb decreased to 65.8°C in the presence of 1.5 M NaCl, while that of the control was 69.4°C. STPP at pH 9 decreased Td of Hb to 61.4°C. The alkaline pH induced by STPP destabilized the Hb structure. RBSs were observed at 100% incidence when cooked to core temperatures of 50 and 70°C for 1min. RBSs were completely eliminated at core temperature of 85°C. The ingredients used during marination appeared to have a minimal effect on RBS formation due to their limited absorption into the chicken breast. The cooking temperature is a major factor governing RBSs, as it directly affects the denaturation of Hb.

Biomolecular interactions of selected buffers with hemoglobin

To elucidate the influence of commonly used biological buffers on the hemoglobin (Hb) structure, biomolecular interactions between Hb and the selected buffers, including tris (hydroxymethyl) aminomethane (TRIS), N-[tris (hydroxymethyl) methyl]-3-aminopropanesulfonic acid (TAPS) and N-[tris (hydroxymethyl) methyl]-2-aminoethane-sulfonic-acid (TES), are investigated by using various biophysical spectroscopic and other techniques. The techniques used in this study are ultraviolet–visible (UV–Vis), fluorescence, circular dichroism (CD) and Fourier transform infrared spectroscopy and dynamic light scattering. Fluorescence spectra analysis reveals that the addition of biological buffers increases the hydrophobicity around the tryptophan environment in Hb. Evidently, the alpha-helix structure of Hb was slightly destroyed at higher concentrations of the buffers detected by CD spectroscopy. However, the thermal stability of the protein transition temperature (Tm) gradually increases with an increase in the concentration of the biological buffers. The results also show that generally the biological buffers are able to enhance the stability of Hb.

Probing the structure-function relationship of hemoglobin in living human red blood cells.

Hemoglobin (Hb) is a key component of respiratory system and as such plays important role in human physiology. The studies of Hb's structure and functions are usually performed on cell-free protein; however, it has been shown that there are functionally relevant differences between isolated Hb and Hb present inside red blood cells (RBCs). It is clear that new experimental approaches are needed to understand the origin of these differences and to gain insight into the structure-function relationship of Hb within intact living cells. In this work we present a novel application of Resonance Raman spectroscopy to study heme active site of different forms of human Hb within living RBCs using laser excitation lines in resonance with their Soret absorption bands. These studies revealed that there are no significant changes in the disposition of the Fe-O-O fragment or the Fe-NHis linkage for Hb molecules enclosed in RBCs and these in free isolated states. However, some changes in the orientation of the heme vinyl groups were observed which might account for the differences in the protein activity and ligand affinity. This work highlights importance of protein-based studies and presents a new opportunity to translate these results to physiological cell systems.

Hemoglobin structure at higher levels of hemoglobin A1C in type 2 diabetes and associated complications.

Background:Fourier transform infrared (FTIR) spectroscopy technique has not been used as a diagnostic tool for diabetes in clinical practice. This study was linked to structural changes in hemoglobin (Hb) in type 2 diabetes patients at higher levels of HbA1C using FTIR spectroscopy.Methods:Fifty-three diabetic patients from the Bahawal Victoria Hospital, Bahawalpur, Pakistan were categorized as group A (6% < HbA1C < 7%; n = 25) and group B (HbA1C ≥9%; n = 28). Another group (group N) of twenty blood samples was taken from healthy people from the Islamia University Bahawalpur, Pakistan. Data from all groups were collected from January 1, 2018 to March 31, 2019. The structure of Hb was studied by FTIR spectroscopy and impact of glucose on the fine structure of HbA1C was estimated.Results:Hb secondary structure erythrocyte parameters were altered by changing glucose concentrations. From FTIR spectra of all three groups it was found that Hb structure was slightly altered in group A, but significantly changed in group B (P < 0.05). There was an increase in β-sheet structure and a reduction in α-helix structure at elevated levels of HbA1C (group B) in type 2 diabetes.Conclusion:We suggest that higher level of glycation reflected by increased HbA1C might be a contributing factor to structural changes in Hb in type 2 diabetic patients. FTIR spectroscopy can be a novel technique to find pathogenesis in type 2 diabetes.

Parakeet Hemoglobin - Its Crystal Structure and Oxygen Affinity in Relation to Some Avian Hemoglobins.

"Avians" often show efficient oxygen management to meet the demands of their metabolism. Hemoglobin, a transporter protein consists of four non-covalently linked subunits contain haem binding hydrophobic pocket serves as a site of allosteric cooperativity. The physiology and anatomy of both mammals and avian are functionally different, in birds, the respiratory system formed by small air sacs that serve as tidal ventilation for the lungs and have no significant exchange across their cells. Parakeet (Psittacula krameri) a tropical and non-migrating species and it is easily adapted to living in disturbed habitat. The sequence analysis reveals that α and β chain of parakeet hemoglobin highly similar grey lag goose and bar headed goose hemoglobin respectively. Thus it has been tempted us to study in to analyzing the sequence and structural comparison of this hemoglobin to find out the physiological capabilities of parakeet hemoglobin. The structure determination studies of parakeet hemoglobin by X-ray diffraction. The sequence and structure are compared with goose, chicken and human Hb, emphasizing the role of amino acids in the subunit contacts that facilitate survival by low oxygen demand. The Hb was purified and crystallized by hanging drop vapor diffusion method using poly ethylene glycol (PEG) 3350 and sodium phosphate buffer. X-ray diffracted data set was collected at 3Å resolution, the data was processed in Automar and molecular replacement, refinements, model building was carried out in CCP4i program package. The final refined model was deposited in protein data bank with accession id 2zfb. The tertiary structure of Parakeet Hb is compared with the met form of BHG Hb (1c40) and oxy form of GLG (1faw) and oxy form of human Hbs (1hho). Superimposing parakeet Hb α1β1 subunit with 'R' state human Hb shows an r.m.s.d of 0.98 Å and for BHG and GLG Hb, the r.m.s.d shows 0.72 and 0.61 Å. The replacement of α115Asp in parakeet Hb as against the α115Glu in human Hb results in the movement of GH corners. The amino acid proline at α50 present only in Parakeet Hb and Chicken HbD and not present in any other avian family which includes human Hb. The residue α78Thr located in EF corner loop region, which slightly diverge when superimposing with human and BHG Hb and also replacement of α113Asn present only in Parakeet Hb placed near the FG helix corner. The present study describes the structure determination of parakeet hemoglobin and its structural features to understand its oxygen affinity characteristics. The crystals were obtained by buffered low-salt conditions, like those of chicken HbD, carbonmonoxy and cyanomet human Hb. The present study reveals several interesting and unique modifications in the finer aspects of the quaternary structure of parakeet Hb, which are involved in oxygen affinity characteristics and the α1β1 subunit contacts. Crystallization of parakeet Hb with allosteric effectors like Inositol pentaphosphate may bring further understanding of the influence of physiological and environmental factors on the quaternary structure.

Interaction of the synthesized anticancer compound of the methyl-glycine 1,10-phenanthroline platinum nitrate with human serum albumin and human hemoglobin proteins by spectroscopy methods and molecular docking

In the present study, the interaction of the novel synthesized platinum complex named methyl-glycine 1,10-phenanthroline platinum nitrate product with two most crucial blood carrier proteins of hemoglobin (Hb) and human serum albumin (HSA) has been investigated. Notably, structural alternation ability of the above anticancer compound was assessed at various temperatures through multispectroscopic techniques such as far-UV circular dichroism (CD) and fluorescence with the participation of the molecular docking targeting Hb and HSA in the systems of the medicine delivery. Fluctuations in the inherent fluorescence intensities of the proteins in consequence of the Pt(II) complex binding represented statics of the quenching system. It should be mentioned that thermodynamic and binding parameters have been calculated through the analysis of the outcomes of the quenching and outcomes of van’t Hoff equation for the two proteins. Theoretical and experimental findings pointed out that the leading force for the Pt(II) complex interaction was electrostatic for HSA and hydrophobic interactions for Hb. Moreover, fluorescence experiments discovered that one binding site would be available because of the Pt(II) complex binding in the two proteins accompanied by a negative Gibbs free energy value. Additionally, the far-UV CD outputs suggested that the Pt(II) complex would cause some variations in the regular secondary and tertiary structures of the HSA as the remarkable going down in the α helical contents of proteins structures at different temperatures equal to 25 °C and 37 °C; however, any noteworthy modifications have not been seen in the respective structures of Hb. However, the interaction between the newly made-up medicine (Pt(II) complex) and the two most crucial blood carrier proteins of the Hb and HSA made a notable shifting in the structures and conformations of the proteins via many fluctuations in the secondary and tertiary structures of the two proteins. Hence, such researches of designing the novel metal anticancer medicines may gather useful data for exploring the more suitable path in the face-off with severe disorders like various cancers through inventing and developing metal medical compounds that are more advantageous and have fewer consequences.

Distinctive structural properties of THB11, a pentacoordinate Chlamydomonas reinhardtii truncated hemoglobin with N- and C-terminal extensions

Hemoglobins (Hbs) utilize heme b as a cofactor and are found in all kingdoms of life. The current knowledge reveals an enormous variability of Hb primary sequences, resulting in topological, biochemical and physiological individuality. As Hbs appear to modulate their reactivities through specific combinations of structural features, predicting the characteristics of a given Hb is still hardly possible. The unicellular green alga Chlamydomonas reinhardtii contains 12 genes encoding diverse Hbs of the truncated lineage, several of which possess extended N- or C-termini of unknown function. Studies on some of the Chlamydomonas Hbs revealed yet unpredictable structural and biochemical variations, which, along with a different expression of their genes, suggest diverse physiological roles. Chlamydomonas thus represents a promising system to analyze the diversification of Hb structure, biochemistry and physiology. Here, we report the crystal structure, resolved to 1.75 Å, of the heme-binding domain of cyanomet THB11 (Cre16.g662750), one of the pentacoordinate algal Hbs, which offer a free Fe-coordination site in the reduced state. The overall fold of THB11 is conserved, but individual features such as a kink in helix E, a tilted heme plane and a clustering of methionine residues at a putative tunnel exit appear to be unique. Both N- and C-termini promote the formation of oligomer mixtures, and the absence of the C terminus results in reduced nitrite reduction rates. This work widens the structural and biochemical knowledge on the 2/2Hb family and suggests that the N- and C-terminal extensions of the Chlamydomonas 2/2Hbs modulate their reactivity by intermolecular interactions.

Structure and function of crocodilian hemoglobins and allosteric regulation by chloride, ATP, and CO2.

Hemoglobins (Hbs) of crocodilians are reportedly characterized by unique mechanisms of allosteric regulatory control, but there are conflicting reports regarding the importance of different effectors, such as chloride ions, organic phosphates, and CO2. Progress in understanding the unusual properties of crocodilian Hbs has also been hindered by a dearth of structural information. Here, we present the first comparative analysis of blood properties and Hb structure and function in a phylogenetically diverse set of crocodilian species. We examine mechanisms of allosteric regulation in the Hbs of 13 crocodilian species belonging to the families Crocodylidae and Alligatoridae. We also report new amino acid sequences for the α- and β-globins of these taxa, which, in combination with structural analyses, provide insights into molecular mechanisms of allosteric regulation. All crocodilian Hbs exhibited a remarkably strong sensitivity to CO2, which would permit effective O2 unloading to tissues in response to an increase in metabolism during intense activity and diving. Although the Hbs of all crocodilians exhibit similar intrinsic O2-affinities, there is considerable variation in sensitivity to Cl- ions and ATP, which appears to be at least partly attributable to variation in the extent of NH2-terminal acetylation. Whereas chloride appears to be a potent allosteric effector of all crocodile Hbs, ATP has a strong, chloride-independent effect on Hb-O2 affinity only in caimans. Modeling suggests that allosteric ATP binding has a somewhat different structural basis in crocodilian and mammalian Hbs.

Biocompatibility of surface-modified gold nanoparticles towards red blood cells and haemoglobin

Studies related to corona formation have been carried out largely for proteins and nanomaterials, however specific studies about the synthesis of nano-systems with bio-benign surface designing and their biological effect on red blood cells (RBCs) lysis is still inadequate. Therefore, it is prime requisite to synthesize gold nanoparticles (AuNPs) which are free from harmful stabilizers to mitigate their biological nano-toxicology. In present work, we evaluate the absolute task, starting from the synthesis of surface designed AuNPs to in vitro physiochemical study of their concentration gradient effect on RBCs toxicity and thermal and structural stability of haemoglobin (Hb). Five-fold and multiple folds twinned AuNPs of different shapes, sizes and zeta-potential are prepared using two novel tryptophan based ionic liquids possessing tryptophan (Trp) group as reducing agent. From the results, it can be determined that both AuNPs are having negative charge fabrication with face centred cubic lattice. Subsequently, the hemolysis percentage results reveal the exceedingly biocompatible nature of AuNPs providing less than 3% hemolysis of cholinium tryptophan-based AuNPs ([CHO][Trp]AuNPs). Moreover, the secondary structure of Hb remains unaltered with no significant change in its thermal stability was observed even for higher concentration of AuNPs.

Hemoglobin: Structure, Function and Allostery.

This chapter reviews how allosteric (heterotrophic) effectors and natural mutations impact hemoglobin (Hb) primary physiological function of oxygen binding and transport. First, an introduction about the structure of Hb is provided, including the ensemble of tense and relaxed Hb states and the dynamic equilibrium of Hb multistate. This is followed by a brief review of Hb variants with altered Hb structure and oxygen binding properties. Finally, a review of different endogenous and exogenous allosteric effectors of Hb is presented with particular emphasis on the atomic interactions of synthetic ligands with altered allosteric function of Hb that could potentially be harnessed for the treatment of diseases.

Multimodal detection and analysis of a new type of advanced Heinz body-like aggregate (AHBA) and cytoskeleton deformation in human RBCs.

A new type of aggregate, formed in human red blood cells (RBCs) in response to glutaraldehyde treatment, was discovered and analyzed with the classical and advanced biomolecular imaging techniques. Advanced Heinz body-like aggregates (AHBA) formed in a single human RBC are characterized by a higher level of hemoglobin (Hb) degradation compared to typical Heinz bodies, which consist of hemichromes. The complete destruction of the porphyrin structure of Hb and the aggregation of the degraded proteins in the presence of Fe3+ ions are observed. The presence of such aggregated, highly degraded proteins inside RBCs, without cell membrane destruction, has been never reported before. For the first time the spatial differentiation of two kinds of protein mixtures inside a single RBC, with different phenylalanine (Phe) conformations, is visualized. The non-resonant Raman spectra of altered RBCs with AHBA are characterized by the presence of a strong band located at 1037 cm-1, which confirms that glutaraldehyde interacts strongly with Phe. The shape-shifting of RBCs from a biconcave disk to a spherical structure and sinking of AHBA to the bottom of the cell are observed. Results reveal that the presence of AHBA should be considered when fixing RBCs and indicate the analytical potential of Raman spectroscopy, atomic force microscopy and scanning near-field optical microscopy in AHBA detection and analysis.

Hemoglobinopathy correction with CRISPR or not; Gene therapy is the solution

Hemoglobin (Hb) disorders or hemoglobinopathies are groups of blood conditions involving inherited genetic diseases – mostly as single-gene autosomal recessive – that lead to the formation of abnormal Hb structure or inadequate to no production of globin chains in Hbs. Disorders of Hb are a global concern since these diseases can cause severe morbidity and early mortality of the affected populations. Treatments vary between chemicals and molecular approaches. The most promising approach is Hb correction. However, the stability of the correction faces a big challenge along with safety concerns. It is worth noting that most of the inherited hemoglobinopathies share common clinical presentations and laboratory findings, although some have distinct features. Hemoglobinopathies with emphasis on recent advances in gene therapy targeting sickle cell disease and thalassemia are discussed in this review.

Pharmacological interventions for painful sickle cell vaso-occlusive crises in adults.

Pharmacological interventions for painful sickle cell vaso-occlusive crises in adults.