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1.
Neurogenetics ; 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38795246

RESUMO

Primary microcephaly is a rare neurogenic and genetically heterogeneous disorder characterized by significant brain size reduction that results in numerous neurodevelopmental disorders (NDD) problems, including mild to severe intellectual disability (ID), global developmental delay (GDD), seizures and other congenital malformations. This disorder can arise from a mutation in genes involved in various biological pathways, including those within the brain. We characterized a recessive neurological disorder observed in nine young adults from five independent consanguineous Pakistani families. The disorder is characterized by microcephaly, ID, developmental delay (DD), early-onset epilepsy, recurrent infection, hearing loss, growth retardation, skeletal and limb defects. Through exome sequencing, we identified novel homozygous variants in five genes that were previously associated with brain diseases, namely CENPJ (NM_018451.5: c.1856A > G; p.Lys619Arg), STIL (NM_001048166.1: c.1235C > A; p.(Pro412Gln), CDK5RAP2 (NM_018249.6 c.3935 T > G; p.Leu1312Trp), RBBP8 (NM_203291.2 c.1843C > T; p.Gln615*) and CEP135 (NM_025009.5 c.1469A > G; p.Glu490Gly). These variants were validated by Sanger sequencing across all family members, and in silico structural analysis. Protein 3D homology modeling of wild-type and mutated proteins revealed substantial changes in the structure, suggesting a potential impact on function. Importantly, all identified genes play crucial roles in maintaining genomic integrity during cell division, with CENPJ, STIL, CDK5RAP2, and CEP135 being involved in centrosomal function. Collectively, our findings underscore the link between erroneous cell division, particularly centrosomal function, primary microcephaly and ID.

2.
PLoS One ; 18(9): e0285874, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37751416

RESUMO

Interleukin-17F (IL-17F), considered a pro-inflammatory cytokine, has been shown to contribute to skeletal tissue degradation and hence chronic inflammation in rheumatoid arthritis (RA). In this study we utilized bioinformatics tools to analyze the effect of three exonic SNPs (rs2397084, rs11465553, and rs763780) on the structure and function of the IL-17F gene, and evaluated their association with RA in Pakistani patients. The predicted deleterious and damaging effects of identified genetic variants were assessed through the utilization of multiple bioinformatics tools including PROVEAN, SNP&GO, SIFT, and PolyPhen2. Structural and functional effects of these variants on protein structures were evaluated through the use of additional tools such as I-Mutant, MutPred, and ConSurf. Three-dimensional (3D) models of both the wild-type and mutant proteins were constructed through the utilization of I-TASSER software, with subsequent structural comparisons between the models conducted through the use of the TM-align score. A total of 500 individuals, 250 cases and 250 controls, were genotyped through Tri-ARMS-PCR method and the resultant data was statistically analyzed using various inheritance models. Our bioinformatics analysis showed significant structural differences for wild type and mutant protein (TM-scores and RMSD values were 0.85934 and 2.34 for rs2397084 (E126G), 0.87388 and 2.49 for rs11465553 (V155I), and 0.86572 and 0.86572 for rs763780 (H161R) with decrease stability for the later. Overall, these tools enabled us to predict that these variants are crucial in causing disease phenotypes. We further tested each of these single nucleotide variants for their association with RA. Our analysis revealed a strong positive association between the genetic variant rs763780 and the risk of developing rheumatoid arthritis (RA) at both the genotypic and allelic levels. The genotypic association was statistically significant[χ2 = 111.8; P value <0.0001], as was the allelic level [OR 3.444 (2.539-4.672); P value 0.0008]. These findings suggest that the presence of this genetic variant may increase the susceptibility to RA. Similarly, we observed a significant distribution of the genetic variant rs11465553 at the genotypic level [χ2 = 25.24; P value = 0.0001]. However, this variant did not show a significant association with RA at the allelic level [OR = 1.194 (0.930-1.531); P value = 0.183]. However, the distribution of variant rs2397084 was more or less random across our sample with no significant association either at genotypic and or allelic level. Put together, our association study and in silico prediction of decreasing of IL17-F protein stabilty confirmed that two SNPs, rs11465553 and rs763780 are crucial to the suscetibility of and showed that these RA in Pakistani patients.


Assuntos
Artrite Reumatoide , Interleucina-17 , Humanos , Artrite Reumatoide/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Interleucina-17/genética , Proteínas Mutantes/genética , Fenótipo , Polimorfismo de Nucleotídeo Único
3.
Curr Pharm Des ; 29(19): 1504-1515, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37073655

RESUMO

BACKGROUND: Borrelia burgdorferi is regarded as an extremely dangerous bacteria causing infectious disease in humans, resulting in musculoskeletal pain, fatigue, fever and cardiac symptom. Because of all alarming concerns, no such prophylaxis setup has been available against Borrelia burgdorferi till now. In fact, vaccine construction using traditional methods is so expensive and time-consuming. Therefore, considering all concerns, we designed a multi-epitope-based vaccine design against Borrelia burgdorferi using in silico approaches. OBJECTIVE: To design an effective and safe vaccine that can activate cell-mediated and humoral immunity against Borrelia burgdorferi by using various bioinformatics tools. METHODS: The present study utilized different computational methodologies, covering different ideas and elements in bioinformatics tools. The protein sequence of Borrelia burgdorferi was retrieved from the NCBI database. Different B and T cell epitopes were predicated using the IEDB tool. Efficient B and T cell epitopes were further assessed for vaccine construction using linkers AAY, EAAAK and GPGPG, respectively. Furthermore, the tertiary structure of constructed vaccine was predicated, and its interaction was determined with TLR9 using ClusPro software. In addition, further atomic level detail of docked complex and their immune response were further determined by MD simulation and C-ImmSim tool, respectively. RESULTS: A protein with immunogenic potential and good vaccine properties (candidate) was identified based on high binding scores, low percentile rank, non-allergenicity and good immunological properties, which were further used to calculate epitopes. Additionally, molecular docking possesses strong interaction; seventeen H-bonds interactions were reported, such as THR101-GLU264, THR185-THR270, ARG 257-ASP210, ARG 257-ASP 210, ASP259-LYS 174, ASN263-GLU237, CYS 265-GLU 233, CYS 265-TYR 197, GLU267- THR202, GLN 270-THR202, TYR345-ASP 210, TYR345-THR 213, ARG 346-ASN209, SER350- GLU141, SER350-GLU141, ASP 424-ARG220 and ARG426-THR216 with TLR-9. Finally, high expression was determined in E. coli (CAI = (0.9045), and GC content = (72%)). Using the IMOD server, all-atom MD simulations of docked complex affirmed its significant stability. The outcomes of immune simulation indicate that both T and B cells represent a strong response to the vaccination component. CONCLUSION: This type of in-silico technique may precisely decrease valuable time and expenses in vaccine designing against Borrelia burgdorferi for experimental planning in laboratories. Currently, scientists frequently utilize bioinformatics approaches that speed up their vaccine-based lab work.


Assuntos
Borrelia burgdorferi , Vacinas , Humanos , Epitopos de Linfócito T/química , Simulação de Acoplamento Molecular , Vacinologia/métodos , Escherichia coli , Epitopos de Linfócito B/química , Clonagem Molecular , Biologia Computacional , Vacinas de Subunidades Antigênicas/química
4.
Microorganisms ; 10(8)2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-36014032

RESUMO

Theileria annulata is a tick-associated parasite that causes tropical theileriosis in livestock and is responsible for huge economic losses. Studies have been neglected on the effect of Theileria spp. on cattle in Khyber Pakhtunkhwa (KP), Pakistan. The present study was designed to determine the genetic diversity and assess the risk factors associated with Theileria infection in selected districts of KP. Information on the risk factors related to the Theileria infection was collected through a questionnaire. Blood samples were collected from symptomatic cattle from January 2019 to February 2020, identified morphologically through microscopic examination, and processed for molecular characterization using the 18S rRNA gene as a genetic marker. Of the 555 cattle examined (136, 24.5%) and (294, 53%) were found positive for Theileria spp. by microscopic examination and a PCR test, respectively. Based on the PCR test, the highest prevalence of infection was found in district Upper Dir (46/75, 61.3%), followed by Lower Dir (54/90, 60%); Malakand (51/88, 57.9%); Peshawar (40/80, 50%); and Charsadda (52/112, 46.4%), with the lowest in Bajaur (51/110, 46.34%). A BLAST analysis of the 18S rDNA sequences showed 99.5% identity with T. annulata. In a phylogenetic tree, the 18S rDNA sequence of T. annulata clustered with sequences from Pakistan, China, and Italy. A significant association was observed between the prevalence of infection and different host characteristics. The highest infection was found in adult cattle (216/360, 60%); females (218/377, 57.8%); and Holstein Friesian (120/180, 66.6%). Theileria infection was significantly associated with management practices. Higher infection rates were observed in free-grazing cattle (190/412, 42.2%); those kept in unhygienic conditions (246/405, 60.7%); cattle in combined farming systems (165/255, 64.8%); and those in congested stall systems (150/218, 68.8%). Seasonal patterns were found to be significantly associated with infection, and a higher infection rate was observed in summer (215/350, 61.4%) than in winter (79/205, 38.5%). Identified risk factors should be considered in designing practical control approaches to reduce the burden of Theileria infection. Large scale studies are required to explore the diversity of Theileria species in KP, Pakistan.

5.
Drug Chem Toxicol ; 45(1): 301-310, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31742437

RESUMO

Portulacca oleracea L. has been used for treatment of different ailments. The aim of this study was to investigate the effectiveness and possible mechanism of action involved in the anti gastric ulcerogenic effect of Portulacca oleracea. Methanolic extract & subsequent fractions (100, 200 and 400 mg/kg) of Portulacca oleracea (P. oleracea) were administered orally to experimental rabbits one hour before oral administration of HCl/ethanol (40:60). Anti gastric ulcerogenic potential of P. oleracea was evaluated by assessment of gastric pH, pepsin, free acidity, ulcer index, mucus content and total acidity. For the investigation of possible mechanism of action malondialdehyde (MDA), histamine, and H + K + ATPase content were determined in the stomach homogenate. Histopathological study of stomach tissue was carried out by H&E dye. Ethyl acetate fraction (EAF) of P. oleracea was the most potent fraction among all fractions that exhibited efficient protection against acidified ethanol mediated gastric-ulcer. The ethyl acetate fraction (EAF) significantly increased the pH of gastric juice, while pepsin and histamine was observed to decrease significantly in comparison to acidified ethanol group (***p ≤ 0.001). The EAF showed moderately H + K + ATPase inhibitory activity. Moreover, it was also observed that EAF decreased the malondialdehyde (MDA) level in the stomach tissue homogenate showing antioxidant effect. Histopathological studies showed that among the tested fractions, EAF significantly prevented acidified ethanol induced gastric mucosal damage. These results showed that mechanism of anti gastric ulcerogenic potential of P. oleracea could be associated with the reduction in histamine level, H + K + ATPase inhibition and reduced MDA level.


Assuntos
Antiulcerosos , Úlcera Gástrica , Animais , Antiulcerosos/farmacologia , Antiulcerosos/uso terapêutico , Etanol/toxicidade , Mucosa Gástrica , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Coelhos , Solventes/toxicidade , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/prevenção & controle
6.
Vaccines (Basel) ; 10(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35062669

RESUMO

The emergence of drug-resistant lice, acari, and their associated pathogens (APs) is associated with economic losses; thus, it is essential to find new appropriate therapeutic approaches. In the present study, a subtractive proteomics approach was used to predict suitable therapeutics against these vectors and their infectious agents. We found 9701 proteins in the lice (Pediculus humanus var. corporis) and acari (Ixodes scapularis, Leptotrombidium deliense), and 4822 proteins in the proteomes of their APs (Babesia microti, Borreliella mayonii, Borrelia miyamotoi, Borrelia recurrentis, Rickettsia prowazekii, Orientia tsutsugamushi str. Boryong) that were non-homologous to host proteins. Among these non-homologous proteins, 365 proteins of lice and acari, and 630 proteins of APs, were predicted as essential proteins. Twelve unique essential proteins were predicted to be involved in four unique metabolic pathways of lice and acari, and 103 unique proteins were found to be involved in 75 unique metabolic pathways of APs. The sub cellular localization analysis of 115 unique essential proteins of lice and acari and their APs revealed that 61 proteins were cytoplasmic, 42 as membrane-bound proteins and 12 proteins with multiple localization. The druggability analysis of the identified 73 cytoplasmic and multiple localization essential proteins revealed 22 druggable targets and 51 novel drug targets that participate in unique pathways of lice and acari and their APs. Further, the predicted 42 membrane bound proteins could be potential vaccine candidates. Screening of useful inhibitors against these novel targets may result in finding novel compounds efficient for the control of these parasites.

7.
Neurochem Int ; 142: 104893, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33159979

RESUMO

Vitamin D (Vt. D) is one of the vital hormone having multiple functions in various tissues, including brain. Several evidences reported that Vt. D plays a significant part in memory and cognition as its inadequate amount may accelerate cognitive impairment. This study shows for the first time the antioxidant potential of Vt. D against D-Galactose (D-gal) induced oxidative stress mediated Alzheimer disease (AD) pathology in male adult albino mice. The result reveals that the mice exposed to D-gal (120 mg/kg) for eight weeks have pre-and post-synaptic dysfunction and impaired memory investigated through Morris water maze and Y-maze tests. This is followed by the suppressed Nuclear factor erythroid 2-related factor 2 (NRF2), Heme Oxygenase-1 (HO-1) and elevated expressions of Nuclear Factor kappa B (NF-kB), Tumor Necrosis Factor alpha (TNF-α) and Interleukin 1 beta (IL-1ß) proteins in the brain homogenates evaluated through western blotting technique. On the other hand Vt. D (100 µg/kg) administration (three times a week for 4 weeks) activated Silent mating type information regulation 2 homolog 1 (SIRT1) and significantly improved both the neuronal synapse and memory, reduced oxidative stress by upregulating NRF-2 and HO-1 and downregulating NF-kB, TNF-α and IL-1ß proteins expression. Most importantly, Vt. D significantly abrogate the amyloidogenic pathway of amyloid beta (Aß) production against D-gal in the brains of adult male albino mice. These results reveal that Vt. D being an antioxidant agent plays a vital role in reducing the AD pathophysiology in D-gal induced animal model of aging, therefore act as a potential drug candidate in neurodegenerative diseases.


Assuntos
Transtornos da Memória/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Neuroproteção/efeitos dos fármacos , Sirtuína 1/metabolismo , Vitamina D/uso terapêutico , Fatores Etários , Animais , Galactose/toxicidade , Masculino , Aprendizagem em Labirinto , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/prevenção & controle , Camundongos , Simulação de Acoplamento Molecular/métodos , Fator 2 Relacionado a NF-E2/química , NF-kappa B/química , Neuroproteção/fisiologia , Transdução de Sinais , Sirtuína 1/química , Vitamina D/farmacologia
8.
Acta Trop ; 209: 105578, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32533937

RESUMO

Documented reports are limited, showing cutaneous leishmaniasis (CL) as a severe threat to schoolchildren in Pakistan. The present study aimed to investigate the clinico-epidemiology and associated risk factors of CL in local and Afghan male schoolchildren between 6 and 16 years of age. The experimental strategy involved a questionnaire for the collection of information and clinical diagnosis (microscopy and semi-nested PCR) of 113 CL symptomatic schoolchildren out of 8,833 schoolchildren (7,175 local and 1,658 Afghan refugees) studying in nineteen schools of the Upper and Lower Dir Districts, Khyber Pakhtunkhwa, Pakistan. Previous records of CL in Pakistan was studied, and spatial analysis was performed on elevation and agro-ecological maps using Arc-GIS v10.3.1. Active lesions were found predominant (n=113, 1.2%: cutaneous lesions, 97, 86%, and lesions with mucosal involvement, 16, 14%) than scars (20, 0.25%). Active lesions of both local (100, 88%) and Afghan refugees (13, 12%), and infected age groups were found significantly different. Majority of the lesions were dry crusted (98, 86.7%), single (83, 73%), and frequently infecting facial region (59, 52%). Avoiding bed nets, living in mud houses and animal shelters were highly associated with CL infection. Temergara (30, 26.5%) and Rabath (14, 12.3%) were hyperendemic CL foci. Microscopically, 71 (63%) cases were positive, while the PCR assay revealed Leishmania tropica in 110 (97.3%) cases. Previous record revealed that L. tropica is dominant throughout Pakistan, and dry mountains and plateaus of northwestern and southwestern regions are spatially at high-risk. Measures should be taken to reduce CL infection by eliminating the associated risk factors, promoting PCR-based diagnosis and basic medical facilities.


Assuntos
Leishmaniose Cutânea/epidemiologia , Adolescente , Animais , Criança , Humanos , Leishmaniose Cutânea/etiologia , Leishmaniose Cutânea/prevenção & controle , Masculino , Paquistão/epidemiologia , Fatores de Risco
9.
Iran J Biotechnol ; 18(4): e2680, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34056027

RESUMO

BACKGROUND: Plant growth, reproduction and yields are severely damaged under adverse environmental stresses. These stresses can be either biotic or abiotic, and many stress related proteins are expressed in response to these stresses. Among these proteins dehydrins are reported to have a role primarily in the abiotic stresses. Dehydrins are very diverse proteins and a uniform annotation system is needed for their functional characterization in the future research. OBJECTIVES: The aim of the present work is to identify, classify and analyze the expression of dehydrin proteins under different biotic and abiotic stresses in the selected plant species by using different computational tools. MATERIALS AND METHODS: Prosite database is used for dehydrin proteins identification, and to conform the location of conserved motifs in selected plant species. The dehydrins extracted from uniprot database were annotated, based on the ensemble plant gene id. Subcellular localization was predicted using PSI predictor tool. Dehydrin expression analyses were retrieved form the genevestigator tool. RESULTS: Dehydrins were annotated on the basis of dehydrin gene locus and conserved motifs available in different domain databases. Dehydrins were identified and annotated in Arabidopsis thaliana (13), Glycine max (12), Zea mays (05), Oryza sativa (11), Solanum tuberosum (05), Solanum lycopersicum (06), Triticum aestivum (32) and Vitis vinifera (06). It has been proposed that dehydrins are located primarily in cytosol and nucleus. Based on genevestigater expression analyses the plant species selected for this study contain all the classes of dehydrins, namely YnSKn, Kn, SKn, and YnKn; except class KnS. CONCLUSIONS: Dehydrins are diverse proteins and a uniform classification is introduced for their better characterization. The distribution of dehydrins in different tissues and developmental stages suggest an important function throughout plant growth cycle. It has also been concluded that dehydrins expressed particularly in drought, cold and salt stresses, and may have limited role in heat, anoxia, heavy-metal and biotic stresses as well.

10.
Biologicals ; 63: 89-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31685418

RESUMO

Pseudomonas aeruginosa is Gram-negative bacterium, one of the leading cause of drug-resistant nosocomial infections in developing countries. This bacterium possesses chromosomally encoded efflux pumps, poor permeability of outer-membrane and high tendency for biofilm formation which are tools to confer resistance. Bacteriophages are regarded as feasible treatment option for control of resistant P. aeruginosa. The aim of the current study was isolate and characterized a bacteriophage against P. aeruginosa with MDR and biofilm ability. A bacteriophage MA-1 with moderate host range was isolated from waste water. The phage was considerable heat and pH stable. Electron microscopy revealed that phage MA-1 belongs to Myoviridae family. Its genome was dsDNA (≈50 kb), coding for eighteen different proteins (ranging from 12 to 250 KDa). P. aeruginosa-2949 log growth phase was significantly reduced by phage MA-1 (2.5 × 103 CFU/ml) as compared to control (without phage). Phage MA-1 also showed significant reductions of 2.0, 2.5 and 3.2 folds in 24, 48, and 74 h old biofilms after 6 h treatment with phage respectively as compared to control. It was concluded from this study that phage MA-1 has capability of killing P. aeruginosa planktonic cells and biofilm, but for complete eradication cocktail will more effective to avoid resistance.


Assuntos
Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla , Fagos de Pseudomonas/metabolismo , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/virologia
11.
Artif Cells Nanomed Biotechnol ; 47(1): 715-724, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30856344

RESUMO

Elicited plant in vitro cultures are gaining more interest worldwide for their potential in the uniform production of industrially important secondary metabolites. In the present study, different ratios of silver nanoparticles (AgNPs) and plant growth regulators (PGRs) were supplemented to in vitro cultures for the sustainable production of biomass and antioxidant secondary metabolites through callus cultures of Caralluma tuberculata. Results indicated that various concentrations of AgNPs significantly affected the callus proliferation and substantially increased the callus biomass, when combined with PGRs in the MS (Murashige and Skoog) media. The highest fresh (0.78 g/l) and dry (0.051 g/l) biomass accumulation of callus was observed in the cultures raised in vitro at 60 µg/l AgNPs in combination with 0.5 mg/l 2,4-D plus 3.0 mg/l BA. Phytochemical analysis of the callus cultures showed higher production of phenolics (TPC:3.0 mg), flavonoids (TFC:1.8 mg), phenylalanine ammonialyase activity (PAL: 5.8 U/mg) and antioxidant activity (90%), respectively, in the callus cultures established on MS media in the presence of 90 ug/l AgNPs. Moreover, enhanced activities of antioxidant enzymes such as superoxide dismutase (SOD: 4.8 U/mg), peroxidase (POD: 3.3 U/mg), catalase (CAT: 2.5 U/mg) and ascorbate peroxidase (APX: 1.9 U/mg) were detected at higher level (90 ug/l) of AgNPs tested alone for callus proliferation in the MS media. It may be concluded that the AgNPs can be effectively utilized for the enhancement of bioactive antioxidants in the callus cultures of C. tuberculata, a highly medicinal and threatened plant. This protocol can be scaled up for the industrial production of plant biomass and pharmacologically potent metabolites in C. tuberculata.


Assuntos
Apocynaceae/metabolismo , Biomassa , Nanopartículas Metálicas/química , Metabolismo Secundário , Prata/química , Antioxidantes/metabolismo , Apocynaceae/citologia , Apocynaceae/crescimento & desenvolvimento , Flavonoides/metabolismo , Fenóis/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Reguladores de Crescimento de Plantas/química , Técnicas de Cultura de Tecidos
12.
Fish Shellfish Immunol ; 34(2): 667-72, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23261504

RESUMO

In rainbow trout (Oncorhynchus mykiss) it has been shown that high affinity IgM antibodies have a higher degree of disulfide polymerization and a longer half life time. In the present study, distinct IgM sub-variants related to ancestral tetraploidy in salmonid fish were analyzed to reveal possible characteristic differences between these. A monoclonal antibody (MAb4C10) which distinguishes between IgM-A and IgM-B in Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) was further characterized. It was shown that substitution of a proline located in the loop between the B and C beta strands of the third constant domain (µ3) of salmon µA eliminated MAb4C10 reactivity. Accordingly, the reverse substitution in salmon µB restored MAb4C10 reactivity. Molecular cloning of µ cDNA from arctic char (Salvelinus alpinus) revealed two sub-variants (µA-1 and µA-2), i.e. a similar situation as in Atlantic salmon and brown trout. However, arctic char IgM eluted in one peak by anion exchange chromatography, in contrast to salmon and brown trout IgM that are eluted in two peaks. The only characteristic residue of salmon and brown trout µB is an additional cysteine in the C-terminal part of µ4. Most likely, this cysteine is involved in inter-chain disulfide bonding and influences the elution profiles of IgM-A and IgM-B on anion exchange chromatography. Neither of the µ sub-variants in arctic char have the additional cysteine, and char IgM, as well as salmon and brown trout IgM-A, showed a lower degree of inter-chain disulfide bonding than IgM-B when subjected to denaturation and gel electrophoresis under non-reducing conditions. Hybrids of char/salmon expressed µA-1, µA-2, µA and µB, indicating that there are two paralogous Ig heavy chain gene complexes in the haploid genome of char, like in Atlantic salmon. A comparison of salmonid µ sequences is presented, including representatives of Salmoninae (trout, salmon and char), Thymallinae (grayling) and Coregoninae (whitefish).


Assuntos
Anticorpos Monoclonais/genética , Imunoglobulina M/genética , Cadeias mu de Imunoglobulina/genética , Subunidades Proteicas/genética , Salmonidae/imunologia , Animais , Anticorpos Monoclonais/imunologia , Sequência de Bases , Western Blotting , Cromatografia por Troca Iônica , Clonagem Molecular , Biologia Computacional , Primers do DNA/genética , Eletroforese em Gel de Poliacrilamida , Imunoglobulina M/imunologia , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Subunidades Proteicas/imunologia , Análise de Sequência de DNA , Especificidade da Espécie
13.
Mol Immunol ; 48(15-16): 1859-67, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21628072

RESUMO

Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) possess two distinct subpopulations of IgM which can be separated by anion exchange chromatography. Accordingly, there are two isotypic µ genes in these species, related to ancestral tetraploidy. In the present work it was verified by mass spectrometry that IgM of peak 1 (subpopulation 1) have heavy chains previously designated as µB type whereas IgM of peak 2 (subpopulation 2) have heavy chains of µA type. Two adjacent cysteine residues are present near the C-terminal part of µB, in contrast to one cysteine residue in µA. Salmon IgM of both peak 1 and peak 2 contain light chains of the two most common isotypes: IgL1 and IgL3. In contrast to salmon and brown trout, IgM of rainbow trout (Oncorhynchus mykiss) is eluted in a single peak when subjected to anion exchange chromatography. Surprisingly, a monoclonal antibody MAb4C10 against rainbow trout IgM, reacted with µA in salmon, whereas in brown trout it reacted with µB. It is plausible to assume that DNA has been exchanged between the paralogous A and B loci during evolution while maintaining the two sub-variants, with and without the extra cysteine. MAb4C10 was conjugated to magnetic beads and used to separate cells, demonstrating that µ transcripts residing from captured cells were primarily of A type in salmon and B type in brown trout. An analysis of amino acid substitutions in µA and µB of salmon and brown trout indicated that the third constant domain is essential for MAb4C10 binding. This was supported by 3D modeling and was finally verified by studies of MAb4C10 reactivity with a series of recombinant µ3 constructs.


Assuntos
Anticorpos Monoclonais , Cadeias mu de Imunoglobulina/química , Cadeias mu de Imunoglobulina/genética , Salmo salar/genética , Truta/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Separação Celular , Mapeamento de Epitopos , Citometria de Fluxo , Espectrometria de Massas , Modelos Moleculares , Conformação Molecular , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Isoformas de Proteínas , Salmo salar/imunologia , Truta/imunologia
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