Population frequency and age of c.806 C>T mutation in CYB5R3 gene as cause of recessive congenital methemoglobinemia in Yakutia

Type-I recessive congenital methemoglobinemia (RCM) is a rare autosomal disease characterized by a deficiency of the soluble form of nicotineamide adenine dinucleotide (NADH)-cytochrome b5 reductase (b5R) and clinically manifests as cyanosis of skin and mucous membranes. In the Russian Federation, type-I RCM is widely disturbed in Yakutia due to the local founder effect. The molecular genetics cause of type-I RCM in Yakutia is mutation c.806C>T in the CYB5R3 gene. In this work we used 13 polymorphic markers, which flanking the CYB5R3 gene to establish the founder haplotype. The age of the mutation was estimated as about 285 ± 135 years. In this work, we have evaluated the frequency of the c.806C>T mutation in Yakutia, which averaged 55 : 1000 Yakuts. The calculated frequency of disease was 1: 1250 Yakuts.     

The role of porcine cytochrome b5A and cytochrome b5B in the regulation of cytochrome P45017A1 activities

Male pigs are routinely castrated to prevent the accumulation of testicular 16-androstene steroids, in particular 5α-androst-16-en-3-one (5α-androstenone), which contribute to an off-odour and off-flavour known as boar taint. Cytochrome P450C17 (CYP17A1) catalyses the key regulatory step in the formation of the 16-androstene steroids from pregnenolone by the andien-β synthase reaction or the synthesis of the glucocorticoid and sex steroids via 17α-hydroxylase and C17,20 lyase pathways respectively. We have expressed CYP17A1, along with cytochrome P450 reductase (POR), cytochrome b5 reductase (CYB5R3) and cytochrome b5 (CYB5) in HEK-293FT cells to investigate the importance of the two forms of porcine CYB5, CYB5A and CYB5B, in both the andien-β synthase as well as the 17α-hydroxylase and C17,20 lyase reactions. Increasing the ratio of CYB5A to CYP17A1 caused a decrease in 17α-hydroxylase (p < 0.013), a transient increase in C17,20 lyase, and an increase in andien-β synthase activity (p < 0.0001). Increasing the ratio of CYB5B to CYP17A1 also decreased 17α-hydroxylase, but did not affect the andien-β synthase activity; however, the C17,20 lyase, was significantly increased. These results demonstrate the differential effects of two forms of CYB5 on the three activities of porcine CYP17A1 and show that CYB5B does not stimulate the andien-β synthase activity of CYP17A1.     

Clinical,Hormonal, and Genetic Characteristics of 5α-Reductase Type 2 Deficiency in 103 Chinese Patients

Objective5α-Reductase type 2 (5α-RD2) deficiency causes variable degrees of undervirilization in patients. The correlation between its genotype and phenotype is unclear.MethodsWe retrospectively evaluated 103 patients with 46,XY disorders of sex development who were diagnosed with 5α-RD2 deficiency.ResultsThe prevalence of female sex assignment (P = .008) and the incidences of cryptorchidism (P = .0003) and bifid scrotum (P = .0002) in the non-p.R227Q variant group were higher, but there were no significant differences in the incidences of hypospadias and isolated microphallus. The external masculinization score in the non-p.R227Q variant group was lower than that in the homozygous p.R227Q variant (P = .019) and compound heterozygous p.R227Q variant groups (P = .013). The level of anti-Mullerian hormone in the non-p.R227Q variant group was lower than that in the homozygous p.R227Q variant (P < .001) and compound heterozygous p.R227Q variant groups (P = .006). The testosterone-to-dihydrotestosterone ratio of the homozygous p.R227Q variant group was higher than that of the non-p.R227Q variant (P = .018) and compound heterozygous p.R227Q variant groups (P = .029). Twenty-three reportedly pathogenic variants and 11 novel steroid 5α-reductase 2 (SRD5A2) variants were identified.ConclusionCompared with patients without p.R227Q, patients with p.R227Q exhibited higher external masculinization scores and anti-Mullerian hormone expression, a lower prevalence of female sex assignment, and lower incidences of cryptorchidism and bifid scrotum. We identified 23 reportedly pathogenic SRD5A2 variants and 11 novel SRD5A2 variants that led to 5α-RD2 deficiency. We established a genotype-phenotype correlation, and patients with p.R227Q showed a relatively mild phenotype.     

A novel polymorphism in the 5′ untranslated region of theporcine cytochrome b5 (CYB5) gene is associated with decreased fat androstenone level

Raising intact male pigs would have a significant economic impact on the pork industry; however, the presence of 16-androstene (a major cause of boar taint) in meat from male pigs would be highly objectionable to consumers. In pigs, a positive correlation has been found between cytochrome b5 (CYB5) and production of 16-androstene. The search for polymorphism of CYB5 and functional analysis of polymorphism found should have an important impact on the efforts to develop genetic markers to select for low androstenone levels in fat from pigs. The aim of this study was to search the porcine CYB5 gene for mutations, examine its expression, identify genetic polymorphisms, and study how a genetic variation in this enzyme translates into interindividual variation in androstenone levels in fat from pig testis. We have identified a single nucleotide polymorphism (SNP) (G→T) at base 8 upstream of ATG in the CYB5 5′ untranslated region which is associated with a lower fat androstenone level. Of the 229 testis samples tested, 84.8% were homozygous for the variant G, 12.4% were heterozygous, and 2.8% were homozygous for the variant T. Functional analysis of this mutation revealed that an individual homozygous for the T allele showed significantly lower CYB5 activity than an individual homozygous for the G allele. Thus, this may be at least partially responsible for a lower level of androstenone in pigs. Our findings provide an important genetic basis toward the goal of predicting the androstenone status in pigs and developing genetic markers for low androstenone.     

Novel large deletion c.22-1320_633+1224del in the CYB5R3 gene from patients with hereditary methemoglobinemia

Hereditary types I and II methemoglobinemia is a rare autosomal recessive disease due to a deficiency of either soluble or soluble and membrane-bound forms of the enzyme NADH-cytochrome b5 reductase. The molecular genetic bases of both types of the disease consist in changes in the CYB5R3 gene. In this study, the novel and, to date, only large deletion in this gene is described, discovered in two unrelated families with types I and II methemoglobinemia. The common founder haplotype on the chromosomes carrying this mutation was identified. A universal approach for searching for the deletion boundaries was developed, and the c.22-1320_633+1224del deletion breakpoints were determined. In addition, a system for identifying the deletion in heterozygous and homozygous states was designed.     

High-yielding cascade enzymatic synthesis of 5-methyluridine using a novel combination of nucleoside phosphorylases

Abstract

A novel combination of Bacillus halodurans purine nucleoside phosphorylase (BhPNP1) and Escherichia coli uridine phosphorylase (EcUP) has been applied to a dual-enzyme, sequential, biocatalytic one-pot synthesis of 5-methyluridine from guanosine and thymine. A 5-methyluridine yield of >79% on guanosine was achieved in a reaction slurry at a 53 mM (1.5% w/w) guanosine concentration. 5-Methyluridine is an intermediate in synthetic routes to thymidine and the antiretroviral drugs zidovudine and stavudine.     

In Silico Design,Synthesis, and In Vitro Evaluation of Novel Amphipathic Short Linear Peptides Against Clinically Relevant Bacterial Biofilms

Microbial biofilms are organized communities of cells that are associated with a wide spectrum of resistant and chronic infections that lead to the treatment failure. Accordingly, there is an urgent demand to create novel effective therapeutic drugs that can inhibit biofilm formation with new mechanisms of action to surmount the current escalating resistance. In this study, in silico hybrid model was utilized to develop three novel short linear peptides (4, 5, and 6) with potential biofilm inhibiting activities (scores?>?1.0). The peptides were composed of cationic and hydrophobic residues. They were synthesized using solid-phase strategy. Synthesized peptides were purified and characterized by reverse-phase high-performance liquid chromatography and matrix-assisted laser desorption/ionization spectroscopy, respectively. They were evaluated using in vitro assay as potential inhibitors of clinically relevant Gram-positive and Gram-negative biofilms. Peptide (4) with five positive charges at physiological pH (4 cationic moieties and W:R?=?1:4) showed activity against biofilms of Gram-positive strains (Staphylococcus epidermidis and Listeria monocytogenes). On the other hand, peptide (5) with six positive charges (5 cationic moieties and W:R?=?2:2) demonstrated activity against Gram-positive (S. epidermidis) and Gram-negative (Escherichia coli) biofilms. Interestingly, peptide (6), with seven positive charges (6 cationic moieties and W:R?=?2:5) revealed higher and broader spectrum of activity against biofilms of Gram-positive (S. epidermidis, S. aureus, L. monocytogenes) and Gram-negative (E. coli).

     

Structure Guided Chemical Modifications of Propylthiouracil Reveal Novel Small Molecule Inhibitors of Cytochrome b5 Reductase 3 That Increase Nitric Oxide Bioavailability

NADH cytochrome b₅ reductase 3 (CYB5R3) is critical for reductive reactions such as fatty acid elongation, cholesterol biosynthesis, drug metabolism, and methemoglobin reduction. Although the physiological and metabolic importance of CYB5R3 has been established in hepatocytes and erythrocytes, emerging investigations suggest that CYB5R3 is critical for nitric oxide signaling and vascular function. However, advancement toward fully understanding CYB5R3 function has been limited due to a lack of potent small molecule inhibitors. Because of this restriction, we modeled the binding mode of propylthiouracil, a weak inhibitor of CYB5R3 (IC₅₀ = ∼275 μm), and used it as a guide to predict thiouracil-biased inhibitors from the set of commercially available compounds in the ZINC database. Using this approach, we validated two new potent derivatives of propylthiouracil, ZINC05626394 (IC₅₀ = 10.81 μm) and ZINC39395747 (IC₅₀ = 9.14 μm), both of which inhibit CYB5R3 activity in cultured cells. Moreover, we found that ZINC39395747 significantly increased NO bioavailability in renal vascular cells, augmented renal blood flow, and decreased systemic blood pressure in response to vasoconstrictors in spontaneously hypertensive rats. These compounds will serve as a new tool to examine the biological functions of CYB5R3 in physiology and disease and also as a platform for new drug development.     

CYB5A polymorphism increases androgens and reduces risk of rheumatoid arthritis in women

IntroductionRheumatoid arthritis (RA) is characterized by decreased androgen levels, which was the first hormonal abnormality described. Several studies indicated that steroidogenesis is directed towards endogenous glucocorticoids at the expense of androgens. The decisive step governing androgen synthesis is the 17,20-lyase activity of the CYP17A1 gene-encoded enzyme cytochrome P450 17A1. Here, we focused on the role in RA of the critical cofactor for 17,20-lyase activity, cytochrome b5, encoded by the CYB5A gene.MethodsData sets of two genome wide RA association studies (GWAS) were screened for single nucleotide polymorphisms (SNP) in the CYB5A gene. Candidate SNPs in CYB5A were studied in a case–control study population of Slovakia. Expression analyses were done in synovial fibroblasts from RA patients by quantitative real-time polymerase chain reaction, and cytochrome b5–expression was detected by immunohistochemistry. Real-life androgen production after steroid conversion was measured using radiolabeled substrates.ResultsThe study identified the RA-associated intronic SNP rs1790834 in the CYB5A gene in one GWAS and confirmed the same SNP in our study. The minor allele reduced RA risk selectively in women (P = 4.1*10⁻³; OR = 0.63, 95% CI [0.46-0.86]). The protective effect was confined to rheumatoid factor-positive (OR = 0.53, [0.37-0.75]) and anti-cyclic citrullinated peptide-positive (OR = 0.58, [0.41-0.83]) cases, respectively. The protective allele doubles CYB5A mRNA-expression resulting in 2-3fold activation of steroid 17,20-lyase activity, and protective allele was accompanied by a higher density of cytochrome b5-positive cells in synovial tissue.ConclusionsCYB5A is the first RA susceptibility gene involved in androgen synthesis. Our functional analysis of SNP rs1790834 indicates that it contributes to the sex bias observed in RA.     

Amidoxime reductase system containing cytochrome b5 type B (CYB5B) and MOSC2 is of importance for lipid synthesis in adipocyte mitochondria

Reduction of hydroxylamines and amidoximes is important for drug activation and detoxification of aromatic and heterocyclic amines. Such a reductase system was previously found to be of high activity in adipose tissue and liver, and furthermore, in vitro studies using recombinant truncated and purified enzymes suggested the participation of cytochrome b(5) reductase (CYB5R), cytochrome b(5) (CYB5), and molybdenum cofactor sulfurase C-terminal containing 1 and 2 (MOSC1 and -2). Here, we show that purified rat liver outer mitochondrial membrane contains high amidoxime reductase activity and that MOSC2 is exclusively localized to these membranes. Moreover, using the same membrane fraction, we could show direct binding of a radiolabeled benzamidoxime substrate to MOSC2. Following differentiation of murine 3T3-L1 cells into mature adipocytes, the MOSC2 levels as well as the amidoxime reductase activity were increased, indicating that the enzyme is highly regulated under lipogenic conditions. siRNA-mediated down-regulation of MOSC2 and the mitochondrial form of cytochrome b(5) type B (CYB5B) significantly inhibited the reductase activity in the differentiated adipocytes, whereas down-regulation of MOSC1, cytochrome b(5) type A (CYB5A), CYB5R1, CYB5R2, or CYB5R3 had no effect. Down-regulation of MOSC2 caused impaired lipid synthesis. These results demonstrate for the first time the direct involvement of MOSC2 and CYB5B in the amidoxime reductase activity in an intact cell system. We postulate the presence of a novel reductive enzyme system of importance for lipid synthesis that is exclusively localized to the outer mitochondrial membrane and is composed of CYB5B, MOSC2, and a third unknown component (a CYB5B reductase).     

SLC4A11 mutations causative of congenital hereditary endothelial dystrophy (CHED) progressing to Harboyan syndrome in consanguineous Pakistani families

Background

Autosomal recessive corneal hereditary endothelial dystrophy (CHED) is a rare congenital disorder of cornea. Mutations in SLC4A11 gene are associated with CHED phenotype. CHED is also an early feature of Harboyan syndrome. The aim of the present study was to identify genetic mutations in the SLC4A11 gene in CHED cases belonging to inbred Pakistani families. Furthermore, all homozygous mutation carriers were investigated for hearing deficit.

Methods and results

This study included consanguineous CHED families presented at Al-Shifa Trust Eye Hospital, Rawalpindi, Pakistan from June 2018 to September 2018. DNA was extracted from blood samples. Direct sequencing of SLC4A11 gene was performed. All identified variants were evaluated by in silico programs i.e., SIFT, PolyPhen‐2, and MutationTaster. Pathogenicity of the two identified splice site variants was analyzed by Human Splicing Finder and MaxEnt Scan. Screening of five CHED families revealed a total of three previously un reported (p.Arg128Gly, c.2241-2A?>?T and c.1898-2A?>?C in family CHED19, CHED22 and CHED26 respectively) and two already reported homozygous disease causing variants (p.Arg869Cys and p.Val824Met in family CHED24 and CHED25 respectively) as predicted by mutation taster. All of these variants segregated with disease phenotype and were not detected in controls.

Conclusion

Affected individuals of the five CHED families screened in this study had the disease due to SLC4A11 mutations and progressing to Harboyan syndrome. Identification of previously unreported mutations aid to heterogeneity of SLC4A11 and CHED pathogenesis as well as helped to provide genetic counseling to affected families.

     

Mutational analysis of CYP1B1 (rs56010818) variant in primary open angle glaucoma (POAG) affected patients of Pakistan

BackgroundPrimary open angle glaucoma (POAG) occurs due to the discrepancies in the angle of anterior chamber characterized by the alterations in intraocular pressure, optic nerves head changes and central loss of visual field. In molecular research, CYP1B1 mutations modulates an integral role in association with glaucoma. Current study was undertaken to reveal the homozygous and heterozygous patterns of CYP1B1 c.1169 G > A variant (rs56010818) in POAG patients of Pakistan.MethodsAfter consent, total n = 88 POAG patients undergone through standard ophthalmological investigations before their recruitment in this study. The blood samples were utilized for DNA isolation. The genotyping of CYP1B1 c.1169 G > A variant was carried out by Sanger sequencing. The mutational patterns and its association with clinical variables were demonstrated by statistical and bioinformatic tools.ResultsIt was evident that the frequencies of heterozygous G/A and homozygous mutants A/A genotypes were higher in males (36.5%, 7.7%) than females (30.6%, 2.8%) of POAG population. Furthermore, the juvenile patients exhibit high manifestation of carrier genotype (66.6%) in comparison to adult patients (31.7%). The results also indicated the significant relationship of intraocular pressure with homozygous mutant A/A genotype of CYP1B1 variant in POAG patients (p < 0.05).ConclusionsOur study provided the mutational data of CYP1B1 R390H variant and the patterns of homozygosity and heterozygosity along with clinical associations. Overall, this study revealed the genetic predisposition of CYP1B1 c.1169 G > A variant in the patients of POAG in Pakistan. The findings could be helpful for genetic screening and in-depth understanding of underlying causes in the pathogenesis of POAG.     

Antioxidant activity of 5-alkoxymethyl-6-chromanols

Abstract

The 5-alkoxymethyl-2,2,7,8-tetramethyl-6-chromanols (II) are excellent antioxidants against autoxidising safflower oil (ASO), although not as good as 2,2,5,7,8-pentamethyl-6-chromanol (I), the model compound of -tocopherol. The aim of this work was to determine whether the rate of reaction of (II) with the radicals diphenylpicrylhydrazyl (DPP^·) and galvinoxyl (ArO^·) was directly proportional to their antioxidant activity against ASO. Compounds (II) reacted faster with DPP^·. than with ArO^·. but, in each case, slower than compound (I). The rates of reaction of I and II with both radicals followed the order I > II (R = H) > II (R = CH₃) > II (R = other alkyls) and were directly proportional to their antioxidant activity against ASO.     

The Involvement of Mitochondrial Amidoxime Reducing Components 1 and 2 and Mitochondrial Cytochrome b5 in N-Reductive Metabolism in Human Cells

The mitochondrial amidoxime reducing component mARC is a recently discovered molybdenum enzyme in mammals. mARC is not active as a standalone protein, but together with the electron transport proteins NADH-cytochrome b₅ reductase (CYB5R) and cytochrome b₅ (CYB5), it catalyzes the reduction of N-hydroxylated compounds such as amidoximes. The mARC-containing enzyme system is therefore considered to be responsible for the activation of amidoxime prodrugs. All hitherto analyzed mammalian genomes code for two mARC genes (also referred to as MOSC1 and MOSC2), which share high sequence similarities. By RNAi experiments in two different human cell lines, we demonstrate for the first time that both mARC proteins are capable of reducing N-hydroxylated substrates in cell metabolism. The extent of involvement is highly dependent on the expression level of the particular mARC protein. Furthermore, the mitochondrial isoform of CYB5 (CYB5B) is clearly identified as an essential component of the mARC-containing N-reductase system in human cells. The participation of the microsomal isoform (CYB5A) in N-reduction could be excluded by siRNA-mediated down-regulation in HEK-293 cells and knock-out in mice. Using heme-free apo-CYB5, the contribution of mitochondrial CYB5 to N-reductive catalysis was proven to strictly depend on heme. Finally, we created recombinant CYB5B variants corresponding to four nonsynonymous single nucleotide polymorphisms (SNPs). Investigated mutations of the heme protein seemed to have no significant impact on N-reductive activity of the reconstituted enzyme system.     

Soil aggregate and particulate C and N under corn rotations: responses to management and correlations with yield

Background

Soil aggregate and particulate organic matter (POM) C and N provide valuable insight into C cycling and storage, and are sensitive to management, but effect of these pools on corn yield is unknown.

Methods

Corn yield, N uptake, and aggregate and POM C and N at 0–5, 5–25 and 25–50 cm were measured and correlated in continuous corn (Zea mays L.) (CC), strip-till corn/soybean [Glycine max (L.) Merr.] (CS), and organically managed corn/soybean/wheat (Triticum aestivum L.) with green manure (CSW).

Results

The POM differed only at 0–5 cm, where greater POM mass was found in CS than CC and CSW. Lower POM-C and POM-N was found in CSW than CC and CS. Overall, CSW had fewer macroaggregates (>250 μm) and associated C and N than CC and CS, but free silt and clay (<53 μm) and microaggregates (53–250 μm) were enriched in C and N in CSW. Yield and macroaggregate-occluded C and N were negatively correlated. Yield and 5–25 cm free silt and clay C were positively correlated.

Conclusions

While organic matter in aggregate-occluded fractions is beneficial for soil C storage, it was correlated with lower grain yields, highlighting a potential tradeoff between yield and long-term C sequestration.

     

Clinical and biological forms of cytochrome b5 reductase deficiency]

Twenty-four personal cases of recessive congenital methemoglobinemia (RCM) due to cytochrome b5 reductase deficiency are analysed. They can be divided into two categories: 1) RCM type I, in which cyanosis is the single clinical symptom; 2) RCM type II in which cyanosis is associated with severe mental retardation and bilateral athetosis. The enzyme deficiency is restricted to the red cell soluble cytochrome b5 reductase in RCM type I, whereas in the type II form the enzyme defect is generalized to all tissues, involving both the soluble and the microsomal forms of cytochrome b5 reductase. Different mutations occurring at the same locus might account for this heterogeneity. However the mechanism of brain damage in case of generalized deficiency of cytochrome b5 reductase is still unknown.     

Complex allele [-102T>A+S549R(T>G)] is associated with milder forms of cystic fibrosis than allele S549R(T>G) alone

We recently reported a novel complex allele in the cystic fibrosis transmembrane regulator ( CFTR) gene, combining a sequence change in the minimal CFTR promoter (-102T>A) and a missense mutation in exon 11 [S549R(T>G)]. Here we compare the main clinical features of six patients with cystic fibrosis (CF) carrying the complex allele [-102T>A+S549R(T>G)] with those of 16 CF patients homozygous for mutation S549R(T>G) alone. Age at diagnosis was higher, and current age was significantly higher (P=0.0032) in the group with the complex allele, compared with the S549R/S549R group. Although the proportion of patients with lung colonization was similar in both groups, the age at onset was significantly higher in the group with the complex allele (P=0.0022). Patients with the complex allele also had significantly lower sweat test chloride values (P=0.0028) and better overall clinical scores (P=0.004). None of the 22 patients reported in this study had meconium ileus. All 16 patients homozygous for S549R(T>G), however, were pancreatic insufficient, as compared with 50% of patients carrying the complex allele (P=0.013). Moreover, the unique patient homozygous for [-102T>A+S549R(T>G)] presented with a mild disease at 34 years of age. These observations strongly suggest that the sequence change (-102T>A) in the CFTR minimal promoter could attenuate the severe clinical phenotype associated with mutation S549R(T>G). Electronic Publication     

Idiopathic atrial fibrillation patients rapidly outgrow their low thromboembolic risk: a 10-year follow-up study

Background

Healthy atrial fibrillation (AF) patients will eventually outgrow their low thromboembolic risk. The purpose of this study is to compare the development of cardiovascular disease in healthy AF patients as compared to healthy sinus rhythm patients and to assess appropriate anticoagulation treatment.

Methods

Forty-one idiopathic paroxysmal AF patients (56 ± 10 years, 66% male) were compared with 45 healthy sinus rhythm patients. Patients were free of hypertension, antihypertensive and antiarrhythmic drugs, diabetes, congestive heart failure, coronary artery or peripheral vascular disease, previous stroke, thyroid, pulmonary and renal disease, and structural abnormalities on echocardiography.

Results

Baseline characteristics and echocardiographic parameters were the same in both groups. During 10.7 ± 1.6 years, cardiovascular disease and all-cause death developed significantly more often in AF patients as compared to controls (63% vs 31%, log rank p < 0.001). Even after the initial 5 years of follow-up, survival curves show divergent patterns (log rank p = 0.006). Mean duration to reach a CHA₂DS₂-VASc score > 1 among AF patients was 5.1 ± 3.0 years. Five of 24 (21%) patients with CHA₂DS₂-VASc > 1 did not receive oral anticoagulation therapy at follow-up. Mean duration of over- or undertreatment with oral anticoagulation in patients with CHA₂DS₂-VASc > 1 was 5 ± 3.0 years.

Conclusion

The majority of recently diagnosed healthy AF patients develop cardiovascular diseases with a consequent change in thromboembolic risk profile within a short time frame. A comprehensive follow-up of this patient category is necessary to avoid over- and undertreatment with anticoagulants.

     

A profound computational study to prioritize the natural compound inhibitors against the P. falciparum orotidine-5-monophosphate decarboxylase enzyme

Abstract

In the current contribution, a multicomplex-based pharmacophore modeling approach was employed on the structural proteome of Plasmodium falciparum orotidine-5-monophosphate decarboxylase enzyme (PfOMPDC). Among the constructed pharmacophore models, the representative hypotheses were selected as the primary filter to screen the molecules with the complementary features responsible for showing inhibition. Thereafter, auxiliary evaluations were performed on the screened candidates via drug-likeness and molecular docking studies. Subsequently, the stability of the docked protein-ligand complexes was scrutinized by employing molecular dynamics simulations and molecular mechanics-Poisson Boltzmann surface area based free binding energy calculations. The stability the docked candidates was compared with the highly active crystallized inhibitor (3S9Y-FNU) to seek more potential candidates. All the docked molecules displayed stable dynamic behavior and high binding free energy in comparison to 3S9Y-FNU. The employed workflow resulted in the retrieval of five drug-like candidates with diverse scaffolds that may show inhibitory activity against PfOMPDC and could be further used as the novel scaffold to develop novel antimalarials.

Communicated by Ramaswamy H. Sarma