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  1. Article ; Online: Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions.

    Cruz, Héctor / Llanes, Alejandro / Fernández, Patricia L

    Journal of visualized experiments : JoVE

    2024  , Issue 203

    Abstract: Many protein-protein interactions involve the binding of short protein segments to peptide-binding domains. Usually, such interactions require the recognition of linear motifs with variable conservation. The combination of highly conserved and more ... ...

    Abstract Many protein-protein interactions involve the binding of short protein segments to peptide-binding domains. Usually, such interactions require the recognition of linear motifs with variable conservation. The combination of highly conserved and more variable regions in the same ligands often contributes to the multispecificity of binding, a common property of enzymes and cell signaling proteins. Characterization of amino acid preferences of peptide-binding domains is important for the design of mediators of protein-protein interactions (PPIs). Computational methods are an efficient alternative to the often costly and cumbersome experimental techniques, enabling the design of potential mediators that can be later validated in downstream experiments. Here, we described a methodology using the Pepspec application of the Rosetta molecular modeling package to predict the amino acid preferences of peptide-binding domains. This methodology is useful when the structure of the receptor protein and the nature of the peptide ligand are both known or can be inferred. The methodology starts with a well-characterized anchor from the ligand, which is extended by randomly adding amino acid residues. The binding affinity of peptides generated this way is then evaluated by flexible-backbone peptide docking in order to select the peptides with the best predicted binding scores. These peptides are then used to calculate amino acid preferences and to optionally compute a position-weight matrix (PWM) that can be used in further studies. To illustrate the application of this methodology, we used the interaction between subunits of human interferon regulatory factor 5 (IRF5), previously known to be multispecific but globally guided by a short conserved motif called pLxIS. The estimated amino acid preferences were consistent with previous knowledge about the IRF5 binding surface. Positions occupied by phosphorylatable serine residues exhibited a high frequency of aspartate and glutamate, likely because their negatively charged side chains are similar to phosphoserine.
    MeSH term(s) Humans ; Amino Acid Sequence ; Amino Acids/metabolism ; Ligands ; Peptides/chemistry ; Proteins/metabolism ; Interferon Regulatory Factors/metabolism ; Protein Binding ; Binding Sites ; Amino Acid Motifs
    Chemical Substances Amino Acids ; Ligands ; Peptides ; Proteins ; Interferon Regulatory Factors
    Language English
    Publishing date 2024-01-26
    Publishing country United States
    Document type Journal Article ; Video-Audio Media
    ZDB-ID 2259946-0
    ISSN 1940-087X ; 1940-087X
    ISSN (online) 1940-087X
    ISSN 1940-087X
    DOI 10.3791/66314
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: First Whole Genome Sequence of

    Llanes, Alejandro / Rajeev, Sreekumari

    Pathogens (Basel, Switzerland)

    2020  Volume 9, Issue 4

    Abstract: We have assembled the first genome draft ... ...

    Abstract We have assembled the first genome draft of
    Language English
    Publishing date 2020-04-10
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2695572-6
    ISSN 2076-0817
    ISSN 2076-0817
    DOI 10.3390/pathogens9040277
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: First Whole Genome Sequence of <i>Anaplasma platys</i>, an Obligate Intracellular Rickettsial Pathogen of Dogs

    Llanes, Alejandro / Rajeev, Sreekumari

    Pathogens. 2020 Apr. 10, v. 9, no. 4

    2020  

    Abstract: We have assembled the first genome draft of ... Anaplasma platys ... , an obligate intracellular rickettsia, and the only known bacterial pathogen infecting canine platelets. ... A. platys ... is a not-yet-cultivated bacterium that causes infectious cyclic ... ...

    Abstract We have assembled the first genome draft of Anaplasma platys, an obligate intracellular rickettsia, and the only known bacterial pathogen infecting canine platelets. A. platys is a not-yet-cultivated bacterium that causes infectious cyclic canine thrombocytopenia, a potentially fatal disease in dogs. Despite its global distribution and veterinary relevance, no genome sequence has been published so far for this pathogen. Here, we used a strategy based on metagenome assembly to generate a draft of the A. platys genome using the blood of an infected dog. The assembled draft is similar to other Anaplasma genomes in size, gene content, and synteny. Notable differences are the apparent absence of rbfA, a gene encoding a 30S ribosome-binding factor acting as a cold-shock protein, as well as two genes involved in biotin metabolism. We also observed differences associated with expanded gene families, including those encoding outer membrane proteins, a type IV secretion system, ankyrin repeat-containing proteins, and proteins with predicted intrinsically disordered regions. Several of these families have members highly divergent in sequence, likely to be associated with survival and interactions within the host and the vector. The sequence of the A. platys genome can benefit future studies regarding invasion, survival, and pathogenesis of Anaplasma species, while paving the way for the better design of treatment and prevention strategies against these neglected intracellular pathogens.
    Keywords Anaplasma platys ; Rickettsia ; bacteria ; biotin ; blood platelets ; cold shock proteins ; design ; dog diseases ; dogs ; genes ; geographical distribution ; metabolism ; metagenomics ; outer membrane proteins ; pathogenesis ; pathogens ; thrombocytopenia ; type IV secretion system
    Language English
    Dates of publication 2020-0410
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article
    Note NAL-light
    ZDB-ID 2695572-6
    ISSN 2076-0817
    ISSN 2076-0817
    DOI 10.3390/pathogens9040277
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: First Whole Genome Sequence of Anaplasma platys , an Obligate Intracellular Rickettsial Pathogen of Dogs

    Alejandro Llanes / Sreekumari Rajeev

    Pathogens, Vol 9, Iss 277, p

    2020  Volume 277

    Abstract: We have assembled the first genome draft of Anaplasma platys , an obligate intracellular rickettsia, and the only known bacterial pathogen infecting canine platelets. A. platys is a not-yet-cultivated bacterium that causes infectious cyclic canine ... ...

    Abstract We have assembled the first genome draft of Anaplasma platys , an obligate intracellular rickettsia, and the only known bacterial pathogen infecting canine platelets. A. platys is a not-yet-cultivated bacterium that causes infectious cyclic canine thrombocytopenia, a potentially fatal disease in dogs. Despite its global distribution and veterinary relevance, no genome sequence has been published so far for this pathogen. Here, we used a strategy based on metagenome assembly to generate a draft of the A. platys genome using the blood of an infected dog. The assembled draft is similar to other Anaplasma genomes in size, gene content, and synteny. Notable differences are the apparent absence of rbfA , a gene encoding a 30S ribosome-binding factor acting as a cold-shock protein, as well as two genes involved in biotin metabolism. We also observed differences associated with expanded gene families, including those encoding outer membrane proteins, a type IV secretion system, ankyrin repeat-containing proteins, and proteins with predicted intrinsically disordered regions. Several of these families have members highly divergent in sequence, likely to be associated with survival and interactions within the host and the vector. The sequence of the A. platys genome can benefit future studies regarding invasion, survival, and pathogenesis of Anaplasma species, while paving the way for the better design of treatment and prevention strategies against these neglected intracellular pathogens.
    Keywords Anaplasma platys ; dogs ; whole genome sequence ; tick-borne pathogens ; Medicine ; R
    Subject code 572
    Language English
    Publishing date 2020-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Complete Genome Sequence of a Virulent Leptospira interrogans Serovar Copenhageni Strain, Assembled with a Combination of Nanopore and Illumina Reads.

    Llanes, Alejandro / Prakoso, Dhani / Restrepo, Carlos Mario / Rajeev, Sreekumari

    Microbiology resource announcements

    2020  Volume 9, Issue 17

    Abstract: Here, we present the complete genome sequence of a highly ... ...

    Abstract Here, we present the complete genome sequence of a highly virulent
    Language English
    Publishing date 2020-04-23
    Publishing country United States
    Document type Journal Article
    ISSN 2576-098X
    ISSN (online) 2576-098X
    DOI 10.1128/MRA.00200-20
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Gene expression patterns associated with Leishmania panamensis infection in macrophages from BALB/c and C57BL/6 mice.

    Restrepo, Carlos M / Llanes, Alejandro / Herrera, Lizzi / Ellis, Esteban / Lleonart, Ricardo / Fernández, Patricia L

    PLoS neglected tropical diseases

    2021  Volume 15, Issue 2, Page(s) e0009225

    Abstract: Leishmania parasites can trigger different host immune responses that result in varying levels of disease severity. The C57BL/6 and BALB/c mouse strains are among the host models commonly used for characterizing the immunopathogenesis of Leishmania ... ...

    Abstract Leishmania parasites can trigger different host immune responses that result in varying levels of disease severity. The C57BL/6 and BALB/c mouse strains are among the host models commonly used for characterizing the immunopathogenesis of Leishmania species and the possible antileishmanial effect of novel drug candidates. C57BL/6 mice tend to be resistant to Leishmania infections, whereas BALB/c mice display a susceptible phenotype. Studying species-specific interactions between Leishmania parasites and different host systems is a key step to characterize and validate these models for in vivo studies. Here, we use RNA-Seq and differential expression analysis to characterize the transcriptomic profiles of C57BL/6 and BALB/c peritoneal-derived macrophages in response to Leishmania panamensis infection. We observed differences between BALB/c and C57BL/6 macrophages regarding pathways associated with lysosomal degradation, arginine metabolism and the regulation of cell cycle. We also observed differences in the expression of chemokine and cytokine genes associated with regulation of immune responses. In conclusion, infection with L. panamensis induced an inflammatory gene expression pattern in C57BL/6 macrophages that is more consistently associated with a classic macrophage M1 activation, whereas in BALB/c macrophages a gene expression pattern consistent with an intermediate inflammatory response was observed.
    MeSH term(s) Animals ; Disease Models, Animal ; Female ; Inflammation Mediators ; Leishmania guyanensis/physiology ; Leishmaniasis/genetics ; Leishmaniasis/metabolism ; Macrophages, Peritoneal/metabolism ; Macrophages, Peritoneal/parasitology ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; RNA-Seq ; Transcriptome ; Mice
    Chemical Substances Inflammation Mediators
    Language English
    Publishing date 2021-02-22
    Publishing country United States
    Document type Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2429704-5
    ISSN 1935-2735 ; 1935-2735
    ISSN (online) 1935-2735
    ISSN 1935-2735
    DOI 10.1371/journal.pntd.0009225
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Genomic Variability among Field Isolates and Laboratory-Adapted Strains of

    Llanes, Alejandro / Restrepo, Carlos Mario / Riesgo-Ferreiro, Pablo / Rajeev, Sreekumari

    International journal of microbiology

    2018  Volume 2018, Page(s) 2137036

    Abstract: Leptospira ... ...

    Abstract Leptospira borgpetersenii
    Language English
    Publishing date 2018-05-22
    Publishing country Egypt
    Document type Journal Article
    ZDB-ID 2467270-1
    ISSN 1687-9198 ; 1687-918X
    ISSN (online) 1687-9198
    ISSN 1687-918X
    DOI 10.1155/2018/2137036
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: VianniaTopes: a database of predicted immunogenic peptides for Leishmania (Viannia) species.

    Llanes, Alejandro / Restrepo, Carlos Mario / Lleonart, Ricardo

    Database : the journal of biological databases and curation

    2018  Volume 2018

    Abstract: Leishmania is a protozoan parasite causing several disease presentations collectively known as leishmaniasis. Pathogenic species of Leishmania are divided into two subgenera, L. (Leishmania) and L. (Viannia). Species belonging to the Viannia subgenus ... ...

    Abstract Leishmania is a protozoan parasite causing several disease presentations collectively known as leishmaniasis. Pathogenic species of Leishmania are divided into two subgenera, L. (Leishmania) and L. (Viannia). Species belonging to the Viannia subgenus have only been reported in Central and South America. These species predominantly cause cutaneous leishmaniasis, but in some cases, parasites can migrate to the nasopharyngeal area and cause a highly disfiguring mucocutaneous presentation. Despite intensive efforts, no effective antileishmanial vaccine is available for use in humans, although a few candidates mainly designed for L. (Leishmania) species are now in clinical trials. After sequencing the genome of Leishmania panamensis, we noticed a high degree of sequence divergence among several orthologous proteins from both subgenera. Consequently, some of the previously published candidates may not work properly for species of the Viannia subgenus. To help in vaccine design, we predicted CD4+ and CD8+ T cell epitopes in the theoretical proteomes of four strains belonging to the Viannia subgenus. Prediction was performed with at least two independent bioinformatics tools, using the most frequent human major histocompatibility complex (MHC) class I and class II alleles in the affected geographic area. Although predictions resulted in millions of peptides, relatively few of them were predicted to bind to several MHC alleles and can therefore be considered promiscuous epitopes. Comparison of our results to previous applications to species of the Leishmania subgenus confirmed that approximately half of the reported candidates are not present in Viannia proteins with a threshold of 80% sequence similarity and coverage. However, our prediction methodology was able to predict 70-100% of the candidates that could be found in Viannia. All the prediction data generated in this study are publicly available in an interactive database called VianniaTopes.
    MeSH term(s) Alleles ; Conserved Sequence ; Databases, Protein ; Epitopes, T-Lymphocyte/immunology ; Internet ; Leishmania/immunology ; Major Histocompatibility Complex ; Peptides/immunology ; Reproducibility of Results ; User-Computer Interface
    Chemical Substances Epitopes, T-Lymphocyte ; Peptides
    Language English
    Publishing date 2018-01-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2496706-3
    ISSN 1758-0463 ; 1758-0463
    ISSN (online) 1758-0463
    ISSN 1758-0463
    DOI 10.1093/database/bay111
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: HLA allele and haplotype frequencies in the Panamanian population.

    Llanes, Alejandro / Ortiz, Luis / Moscoso, Juan / Gutiérrez, Gina / Blake, Elena / Restrepo, Carlos M / Lleonart, Ricardo / Cuero, Cesar / Vernaza-Kwiers, Alejandro

    Human immunology

    2020  Volume 82, Issue 1, Page(s) 5–7

    Abstract: In this study, we report for the first time HLA allele and haplotype frequencies in the modern Panamanian population at a two-field (four digits) resolution level. Reported frequencies were calculated from genotype data for the HLA-A, -B, -C, -DPB1, - ... ...

    Abstract In this study, we report for the first time HLA allele and haplotype frequencies in the modern Panamanian population at a two-field (four digits) resolution level. Reported frequencies were calculated from genotype data for the HLA-A, -B, -C, -DPB1, -DQB1 and -DRB1 loci of 462 healthy unrelated Panamanian adults of Hispanic ethnicity. In addition to providing new insights on the allelic structure of the Panamanian population and its origin, these data are critical for better planning of healthcare strategies in the country and for future research exploring the association with certain chronic and infectious diseases.
    MeSH term(s) Adolescent ; Adult ; Aged ; Alleles ; Female ; Gene Frequency ; Genetics, Population/statistics & numerical data ; Haplotypes ; Healthy Volunteers ; Hispanic Americans/genetics ; Histocompatibility Antigens Class I/genetics ; Histocompatibility Antigens Class II/genetics ; Humans ; Linkage Disequilibrium ; Male ; Middle Aged ; Panama ; Young Adult
    Chemical Substances Histocompatibility Antigens Class I ; Histocompatibility Antigens Class II
    Language English
    Publishing date 2020-12-07
    Publishing country United States
    Document type Journal Article ; Observational Study
    ZDB-ID 801524-7
    ISSN 1879-1166 ; 0198-8859
    ISSN (online) 1879-1166
    ISSN 0198-8859
    DOI 10.1016/j.humimm.2020.11.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: A Computational Approach to Explore the Interaction of Semisynthetic Nitrogenous Heterocyclic Compounds with the SARS-CoV-2 Main Protease.

    Llanes, Alejandro / Cruz, Héctor / Nguyen, Viet D / Larionov, Oleg V / Fernández, Patricia L

    Biomolecules

    2020  Volume 11, Issue 1

    Abstract: In the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic, numerous attempts have been made to discover new potential antiviral molecules against its causative agent, SARS-CoV-2, many of which focus on its main protease ( ... ...

    Abstract In the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic, numerous attempts have been made to discover new potential antiviral molecules against its causative agent, SARS-CoV-2, many of which focus on its main protease (M
    MeSH term(s) Antiviral Agents/chemistry ; Antiviral Agents/therapeutic use ; COVID-19/drug therapy ; COVID-19/epidemiology ; Catalytic Domain ; Coronavirus 3C Proteases/antagonists & inhibitors ; Coronavirus 3C Proteases/chemistry ; Heterocyclic Compounds/chemistry ; Heterocyclic Compounds/therapeutic use ; Humans ; Molecular Dynamics Simulation ; Pandemics ; Protease Inhibitors/chemistry ; Protease Inhibitors/therapeutic use ; SARS-CoV-2/enzymology
    Chemical Substances Antiviral Agents ; Heterocyclic Compounds ; Protease Inhibitors ; Coronavirus 3C Proteases (EC 3.4.22.28)
    Language English
    Publishing date 2020-12-27
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2701262-1
    ISSN 2218-273X ; 2218-273X
    ISSN (online) 2218-273X
    ISSN 2218-273X
    DOI 10.3390/biom11010018
    Database MEDical Literature Analysis and Retrieval System OnLINE

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