Key mutations in HBsAg C-terminus correlate with lower HBsAg levels in vivo, hinder HBsAg release in vitro and affect HBsAg structural stability in HBeAg-negative chronic HBV genotype D infection

2019 ◽  
Vol 51 ◽  
pp. e60
Author(s):  
L. Piermatteo ◽  
A. Battisti ◽  
L. Carioti ◽  
O. Anastasiou ◽  
U.S. Gill ◽  
...  
Keyword(s):  
Structural Stability ◽  
Hbv Genotype ◽  
C Terminus ◽  
Chronic Hbv ◽  
Release In Vitro

scholarly journals A Peptide Found in Human Serum, Derived from the C-Terminus of Albumin, Shows Antifungal Activity In Vitro and In Vivo

2020 ◽  
Vol 8 (10) ◽  
pp. 1627
Author(s):  
Tecla Ciociola ◽  
Pier Paolo Zanello ◽  
Tiziana D’Adda ◽  
Serena Galati ◽  
Stefania Conti ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Human Serum ◽  
Fungicidal Activity ◽  
Galleria Mellonella ◽  
Serum Proteins ◽  
Morphological Alterations ◽  
C Terminus ◽  
Different Sources

The growing problem of antimicrobial resistance highlights the need for alternative strategies to combat infections. From this perspective, there is a considerable interest in natural molecules obtained from different sources, which are shown to be active against microorganisms, either alone or in association with conventional drugs. In this paper, peptides with the same sequence of fragments, found in human serum, derived from physiological proteins, were evaluated for their antifungal activity. A 13-residue peptide, representing the 597–609 fragment within the albumin C-terminus, was proved to exert a fungicidal activity in vitro against pathogenic yeasts and a therapeutic effect in vivo in the experimental model of candidal infection in Galleria mellonella. Studies by confocal microscopy and transmission and scanning electron microscopy demonstrated that the peptide penetrates and accumulates in Candida albicans cells, causing gross morphological alterations in cellular structure. These findings add albumin to the group of proteins, which already includes hemoglobin and antibodies, that could give rise to cryptic antimicrobial fragments, and could suggest their role in anti-infective homeostasis. The study of bioactive fragments from serum proteins could open interesting perspectives for the development of new antimicrobial molecules derived by natural sources.

scholarly journals C-Terminal Deletions Can Suppress Temperature-Sensitive Mutations and Change Dominance in the Phage Mu Repressor

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 661-672 ◽  
Author(s):  
Jodi L Vogel ◽  
Vincent Geuskens ◽  
Lucie Desmet ◽  
N Patrick Higgins ◽  
Ariane Toussaint
Keyword(s):  
Binding Activity ◽  
Temperature Sensitive ◽  
Dna Binding Activity ◽  
Heat Stable ◽  
C Terminus ◽  
Acid Domain ◽  
Mutant Forms ◽  
Amino Acid Domain

Abstract Mutations in an N-terminal 70-amino acid domain of bacteriophage Mu's repressor cause temperature-sensitive DNA-binding activity. Surprisingly, amber mutations can conditionally correct the heat-sensitive defect in three mutant forms of the repressor gene, cts25 (D43-G), cts62 (R47-Q and cts71 (M28-I), and in the appropriate bacterial host produce a heat-stable Sts phenotype (for survival of temperature shifts). Sts repressor mutants are heat sensitive when in supE or supF hosts and heat resistant when in Sup° hosts. Mutants with an Sts phenotype have amber mutations at one of three codons, Q179, Q187, or Q190. The Sts phenotype relates to the repressor size: in Sup° hosts sts repressors are shorter by seven, 10, or 18 amino acids compared to repressors in supE or supF hosts. The truncated form of the sts62-1 repressor, which lacks 18 residues (Q179–V196), binds Mu operator DNA more stably at 42° in vitro compared to its full-length counterpart (cts62 repressor). In addition to influencing temperature sensitivity, the C-terminus appears to control the susceptibility to in vivo Clp proteolysis by influencing the multimeric structure of repressor.

scholarly journals TMOD-24. GENERATION AND CHARACTERIZATION OF A NOVEL TRANSGENIC IDO REPORTER MOUSE FOR IDO POSTTRANSLATIONAL MODIFICATION ANALYSIS IN SITU

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii233-ii233
Author(s):  
April Bell ◽  
Lijie Zhai ◽  
Erik Ladomersky ◽  
Kristen Lauing ◽  
Lakshmi Bollu ◽  
...  
Keyword(s):  
Mouse Model ◽  
Tumor Cell ◽  
Central Nervous System Tumor ◽  
Post Translational Modifications ◽  
Reporter Mouse ◽  
C Terminus ◽  
Human Gbm

Abstract Glioblastoma (GBM) is the most common and aggressive primary central nervous system tumor in adults with a median survival of 14.6 months. GBM is a potently immunosuppressive cancer due in-part to the prolific expression of immunosuppressive indoleamine 2,3 dioxygenase 1 (IDO). Tumor cell IDO facilitates the intratumoral accumulation of regulatory T cells (Tregs; CD4+CD25+FoxP3+). Although immunosuppressive IDO activity is canonically characterized by the conversion of tryptophan into kynurenine, we have utilized transgenic and syngeneic mouse models and mutant glioma lines to demonstrate that tumor cell IDO increases Treg accumulation independent of tryptophan metabolism. Here, we address the gap in our understanding of IDO signaling activity in vivo. Subcutaneously-engrafted human GBM expressing human IDO-GFP cDNA was isolated from immunodeficient humanized NSG-SGM3 mice. The tumor was immunoprecipitated for the GFP tag using GFP-TRAP followed by mass spectrometry which revealed a novel methylation site on a lysine residue at amino acid 373 in the IDO C-terminus region. Western blot analysis of IDO protein also revealed the presence of tyrosine phosphorylation. Additionally, we recently created a new transgenic IDO reporter mouse model whereby endogenous IDO is fused to GFP via a T2A linker (IDO→GFP). This model allows for the isolation of IDO+ cells in real-time and without causing cell death, thereby creating the opportunity for downstream molecular analysis of in situ-isolated GFP+ cells. Collectively, our work suggests that IDO non-enzyme activity may involve the post-translational modifications we recently identified. As IDO activity may differ between in vitro and in vivo modeling systems, we will use the new IDO→GFP reporter mouse model for an improved mechanistic understanding of how immunosuppressive IDO facilitates Treg accumulation in vivo.

Reproduction in Aplysia californica: correlations between egg laying in vivo and egg release in vitro

1980 ◽  
Vol 58 (11) ◽  
pp. 2163-2166 ◽  
Author(s):  
F. Edward Dudek ◽  
Amd Bonnie Soutar ◽  
Stephen S. Tobe
Keyword(s):  
Aplysia Californica ◽  
Egg Laying ◽  
Previous Episode ◽  
Laboratory Conditions ◽  
Release In Vitro

Aspects of egg laying by isolated Aplysia californica and egg release from ovotestis fragments were compared under laboratory conditions. The volume of eggs laid per episode increased as a function of time since the previous episode of egg laying. Egg output in vivo and egg release in vitro were maximal in autumn and minimal in spring, but a factor in the parietovisceral ganglion evoked egg release from ovotestis fragments throughout the year. These data are consistent with previous studies which have suggested that the effects of season and egg-laying history on egg laying involve substantial changes in the ovotestis.

scholarly journals The Designer Antimicrobial Peptide A-hBD-2 Facilitates Skin Wound Healing by Stimulating Keratinocyte Migration and Proliferation

2018 ◽  
Vol 51 (2) ◽  
pp. 647-663 ◽  
Author(s):  
Bobin Mi ◽  
Jing Liu ◽  
Yi Liu ◽  
Liangcong Hu ◽  
Yukun Liu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Wound Healing ◽  
Antimicrobial Peptide ◽  
Structural Stability ◽  
Cell Counting ◽  
Sprague Dawley ◽  
Skin Wound Healing ◽  
High Sodium

Background/Aims: Antimicrobial peptides are effective promoters of wound healing but are susceptible to degradation. In this study, we replaced the GIGDP unit on the N-terminal of the endogenous human antimicrobial peptide hBD-2 with APKAM to produce A-hBD-2 and analyzed the effect on wound healing both in vitro and in vivo. Methods: The effects of A-hBD-2 and hBD-2 on cytotoxicity and proliferation in keratinocytes were assessed by Cell Counting Kit-8 assay. The structural stability and antimicrobial activity of hBD-2 and A-hBD-2 were evaluated against Staphylococcus aureus. RNA and proteins levels were evaluated by real-time PCR and western blotting, respectively. Cell migration was evaluated using a transwell assay. Cell cycle analysis was performed by flow cytometry. Wound healing was assessed in Sprague-Dawley rats. Epidermal thickness was evaluated by hematoxylin and eosin staining. Results: We found that hBD-2 exhibited cytotoxicity at high concentrations and decreased the structural stability in the presence of high sodium chloride concentrations. A-hBD-2 exhibited increased structural stability and antimicrobial activity, and had lower cytotoxicity in keratinocytes. A-hBD-2 increased the migration and proliferation of keratinocytes via phosphorylation of EGFR and STAT3 and suppressed terminal differentiation of keratinocytes. We also found that A-hBD-2 elicited mobilization of intracellular Ca2+ and stimulated keratinocytes to produce pro- and anti-inflammatory cytokines and chemokines via phospholipase C activation. Furthermore, A-hBD-2 promoted wound healing in vivo. Conclusion: Our data suggest that A-hBD-2 may be a promising candidate therapy for wound healing.

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