scholarly journals Algal and Cyanobacterial Lectins and Their Antimicrobial Properties

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 687
Author(s):  
José Abel Fernández Romero ◽  
María Gabriela Paglini ◽  
Christine Priano ◽  
Adolfina Koroch ◽  
Yoel Rodríguez ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Structure Function ◽  
Human Health ◽  
Present Report ◽  
Antimicrobial Properties ◽  
High Affinity ◽  
Freshwater Organisms ◽  
Immunodeficiency Virus ◽  
Further Development ◽  
Virus Influenza

Lectins are proteins with a remarkably high affinity and specificity for carbohydrates. Many organisms naturally produce them, including animals, plants, fungi, protists, bacteria, archaea, and viruses. The present report focuses on lectins produced by marine or freshwater organisms, in particular algae and cyanobacteria. We explore their structure, function, classification, and antimicrobial properties. Furthermore, we look at the expression of lectins in heterologous systems and the current research on the preclinical and clinical evaluation of these fascinating molecules. The further development of these molecules might positively impact human health, particularly the prevention or treatment of diseases caused by pathogens such as human immunodeficiency virus, influenza, and severe acute respiratory coronaviruses, among others.

scholarly journals Novel 4′-Substituted Stavudine Analog with Improved Anti-Human Immunodeficiency Virus Activity and Decreased Cytotoxicity

2004 ◽  
Vol 48 (5) ◽  
pp. 1640-1646 ◽  
Author(s):  
Ginger E. Dutschman ◽  
Susan P. Grill ◽  
Elizabeth A. Gullen ◽  
Kazuhiro Haraguchi ◽  
Shingo Takeda ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Drug ◽  
Antiviral Effect ◽  
Immunodeficiency Virus ◽  
Delayed Toxicity ◽  
Hiv Drugs ◽  
Further Development ◽  
Anti Hiv ◽  
Better Than

ABSTRACT The antiviral drug 2′,3′-didehydro-3′-deoxythymidine (D4T; also know as stavudine and Zerit), which is used against human immunodeficiency virus (HIV), causes delayed toxicity (peripheral neuropathy) in long-term use. After examining a series of 2′,3′-didehydro-3′-deoxy-4′-substituted thymidine (4′-substituted D4T) analogs, 4′-ethynyl D4T was found to have a fivefold-better antiviral effect and to cause less cellular and mitochondrial toxicity than D4T. The antiviral activity of this compound can be reversed by dThd but not by dCyd. The compound acted synergistically with β-l-2′,3′-deoxy-3′-thiacytidine (also known as lamivudine) and β-l-2′,3′-dideoxy-2′,3′-didehydro-5-fluorocytidine (also known as elvucitabine) and additively with 2′,3′-dideoxyinosine (also known as didanosine and Videx) and 3′-azido-3′-deoxythymidine (also known as Retovir and zidovudine) against HIV. 4′-Ethynyl D4T is phosphorylated by purified human thymidine kinase 1 (TK-1) from CEM cells with a faster relative V max and a lower Km value than D4T. The efficiency of TK-1 in the phosphorylation of 4′-ethynyl D4T is fourfold better than that of D4T. While D4T is broken down by the catabolic enzyme thymidine phosphorylase, the level of breakdown of 4′-ethynyl D4T was below detection. Since 4′-ethynyl D4T has increased anti-HIV activity and decreased toxicity and interacts favorably with other currently used anti-HIV drugs, it should be considered for further development as an anti-HIV drug.

scholarly journals CDK9 Autophosphorylation Regulates High-Affinity Binding of the Human Immunodeficiency Virus Type 1 Tat–P-TEFb Complex to TAR RNA

2000 ◽  
Vol 20 (18) ◽  
pp. 6958-6969 ◽  
Author(s):  
Mitchell E. Garber ◽  
Timothy P. Mayall ◽  
Eric M. Suess ◽  
Jill Meisenhelder ◽  
Nancy E. Thompson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Affinity Binding ◽  
High Affinity Binding ◽  
High Affinity ◽  
Immunodeficiency Virus ◽  
Tar Rna ◽  
Cdk9 Phosphorylation ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) Tat interacts with cyclin T1 (CycT1), a regulatory partner of CDK9 in the positive transcription elongation factor (P-TEFb) complex, and binds cooperatively with CycT1 to TAR RNA to recruit P-TEFb and promote transcription elongation. We show here that Tat also stimulates phosphorylation of affinity-purified core RNA polymerase II and glutathioneS-transferase–C-terminal-domain substrates by CycT1-CDK9, but not CycH-CDK7, in vitro. Interestingly, incubation of recombinant Tat–P-TEFb complexes with ATP enhanced binding to TAR RNA dramatically, and the C-terminal half of CycT1 masked binding of Tat to TAR RNA in the absence of ATP. ATP incubation lead to autophosphorylation of CDK9 at multiple C-terminal Ser and Thr residues, and full-length CycT1 (amino acids 728) [CycT1(1–728)], but not truncated CycT1(1–303), was also phosphorylated by CDK9. P-TEFb complexes containing a catalytically inactive CDK9 mutant (D167N) bound TAR RNA weakly and independently of ATP, as did a C-terminal truncated CDK9 mutant that was catalytically active but unable to undergo autophosphorylation. Analysis of different Tat proteins revealed that the 101-amino-acid SF2 HIV-1 Tat was unable to bind TAR with CycT1(1–303) in the absence of phosphorylated CDK9, whereas unphosphorylated CDK9 strongly blocked binding of HIV-2 Tat to TAR RNA in a manner that was reversed upon autophosphorylation. Replacement of CDK9 phosphorylation sites with negatively charged residues restored binding of CycT1(1–303)-D167N-Tat, and rendered D167N a more potent inhibitor of transcription in vitro. Taken together, these results demonstrate that CDK9 phosphorylation is required for high-affinity binding of Tat–P-TEFb to TAR RNA and that the state of P-TEFb phosphorylation may regulate Tat transactivation in vivo.

High-affinity ssDNA inhibitors of the reverse transcriptase of type 1 human immunodeficiency virus

Biochemistry ◽  
1995 ◽  
Vol 34 (29) ◽  
pp. 9599-9610 ◽  
Author(s):  
Daniel J. Schneider ◽  
Juli Feigon ◽  
Zdenek Hostomsky ◽  
Larry Gold
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
High Affinity ◽  
Immunodeficiency Virus

scholarly journals Highly Sensitive Methods for Quantitation of Human Immunodeficiency Virus Type 1 RNA from Plasma, Cells, and Tissues

1999 ◽  
Vol 37 (5) ◽  
pp. 1260-1264 ◽  
Author(s):  
Marek Fischer ◽  
Werner Huber ◽  
Alex Kallivroussis ◽  
Peter Ott ◽  
Milos Opravil ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Mononuclear Cells ◽  
Plasma Cells ◽  
Present Report ◽  
Rt Pcr ◽  
Peripheral Blood Mononuclear ◽  
Enhanced Sensitivity ◽  
Immunodeficiency Virus ◽  
Hiv 1

Precise and sensitive quantitation of viral RNA in specimens from human immunodeficiency virus (HIV) type 1 (HIV-1)-infected individuals has become an indispensable tool for the monitoring of the efficacy of highly active antiretroviral combination therapy. The present report describes reproducible and efficient protocols with enhanced sensitivity for quantitation of HIV-1 RNA from plasma, peripheral blood mononuclear cells, and tissues with Qiagen silica columns for RNA purification combined with the Roche Amplicor HIV-1 Monitor test for quantitative reverse transcription-PCR (RT-PCR). Extraction of RNA from 0.5 ml of plasma resulted in the detection of fewer than 20 HIV RNA copies/ml of plasma, equivalent to the centrifugation-based boosted RT-PCR assay. Silica extraction of cellular RNA resulted in the detection of fewer than 3 HIV-1 RNA copies/μg of total RNA. These techniques facilitate direct comparisons of viral loads between liquid and cellular specimens. Application of these sensitive methods may improve the assessment of the response to new antiretroviral regimens.

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