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Antiviral Activity of Lactoferrin and Ovotransferrin Derived Peptides Towards Herpesviridae
Full text linkNon
Antifungal and Antiparasitic Activities of Lactoferrin
No full textThe first function attributed to lactoferrin, an iron-binding protein belonging to the non-immune natural defences,
was antimicrobial activity related to its capability of sequestering iron. Many other antimicrobial and antiviral
functions have been ascribed to lactoferrin. In vitro activity towards human pathogenic fungi on the part of both human
and bovine lactoferrin has been well documented as well. The antifungal activity appears to be related to lactoferrin interference
with the fungal cell surface rather than iron deprivation and some host-mediated mechanisms of action cannot be
ruled out. Lactoferrin also displays anti-parasitic activity, although the molecular mechanisms of such activity are even
more complex
Lactoferrin from milk: Nutraceutical and pharmacological properties
Full text linkLactoferrin is an iron-binding protein present in large quantities in colostrum and in breast
milk, in external secretions and in polymorphonuclear leukocytes. Lactoferrin’s main function is
non-immune protection. Among several protective activities shown by lactoferrin, those displayed
by orally administered lactoferrin are: (i) antimicrobial activity, which has been presumed due to
iron deprivation, but more recently attributed also to a specific interaction with the bacterial cell wall
and extended to viruses and parasites; (ii) immunomodulatory activity, with a direct effect on the
development of the immune system in the newborn, together with a specific antinflammatory effects;
(iii) a more recently discovered anticancer activity. It is worth noting that most of the protective
activities of lactoferrin have been found, sometimes to a greater extent, also in peptides derived from
limited proteolysis of lactoferrin that could be generated after lactoferrin ingestion. Lactoferrin could
therefore be considered an ideal nutraceutic product because of its relatively cheap production from
bovine milk and of its widely recognized tolerance after ingestion, along with its well demonstrated
protective activities. The most important protective activities shown by orally administered bovine
lactoferrin are reviewed in this article
Nutraceutical Peptides from Lactoferrin
No full textLactoferrin belongs to the transferrin protein superfamily and is a major component of the mammalian innate
immune system. Proteolytic cleavage of either human or bovine lactoferrin results in the generation of several
peptides, most of which manifest the protective activities of Lactoferrin. It is worth noting that these peptides may be
naturally produced in the human intestine after milk ingestion. Interestingly, peptides deriving from proteolytic
cleavage of Ovotransferrin, a Lactoferrin homologous protein present in reptiles and birds, displays the same
protective activities. This mini-review summarizes the most relevant protective activities of peptides deriving from
Lactoferrin and Ovotransferrin
Ac‐tLeu‐Asp‐H is the minimal and highly effective human caspase‐3 inhibitor: biological and in silico studies
No full textCaspase-3 displays a pivotal role as an executioner of apoptosis, hydrolyzing several proteins including the nuclear enzyme poly(ADP-ribose)polymerase (PARP). Ac-Asp-Glu-Val-Asp-H (K i° = 2.3 × 10(-10) M at pH 7.5 and 25.0 °C), designed on the basis of the cleavage site of PARP, has been reported as a highly specific human caspase-3 inhibitor. Here, di- and tri-peptidyl aldehydes 11-13 and 27-29 have been synthesized to overcome the susceptibility to proteolysis, the intrinsic instability, and the scarce membrane permeability of the current inhibitors. Compounds 11-13, 27-29 inhibit in vitro human caspase-3 competitively, values of K i° ranging between 6.5 (±0.82) × 10(-9) M and 1.1 (±0.04) × 10(-7) M (at pH 7.4 and 25.0 °C). Moreover, the most effective caspase-3 inhibitor 11 impairs apoptosis in human DLD-1 colon adenocarcinoma cells. Furthermore, the binding mode of 11-13 and 27-29 to human caspase-3 has been investigated in silico. The comparative analysis of human caspase-3 inhibitors indicates that (1) aldehyde 11 is the minimal highly effective inhibitor, (2) the tLeu-Asp sequence is pivotal for satisfactory enzyme inhibition, and (3) the occurrence of the tLeu residue at the inhibitor P2 position is fundamental for enzyme/inhibitor recognition. Moreover, calculations suggest that the tLeu residue reduces the conformational flexibility of the inhibitor that binds to the enzyme with a lower energetic penalty
The Five-To-Six-Coordination Transition of Ferric Human Serum Heme-Albumin Is Allosterically-Modulated by Ibuprofen and Warfarin: A Combined XAS and MD Study
No full textHuman serum albumin (HSA) is involved physiologically in heme scavenging; in turn, heme-albumin (HSA-heme-Fe) displays
globin-like properties. Here, the allosteric effect of ibuprofen and warfarin on the local atomic structure around the ferric
heme-Fe (heme-Fe(III)) atom of HSA-heme-Fe (HSA-heme-Fe(III)) has been probed by Fe-K edge X-ray absorption
spectroscopy (XAS). The quantitative analysis of the Fe-K edge extended X-ray absorption fine structure (EXAFS) signals and
modeling of the near edge (XANES) spectral features demonstrated that warfarin and ibuprofen binding modify the local
structure of the heme-Fe(III). Combined XAS data analysis and targeted molecular dynamics (MD) simulations provided
atomic resolution insights of protein structural rearrangements required to accommodate the heme-Fe(III) upon ibuprofen
and warfarin binding. In the absence of drugs, the heme-Fe(III) atom is penta-coordinated having distorted 4
+
1
configuration made by the nitrogen atoms of the porphyrin ring and the oxygen phenoxy atom of the Tyr161 residue. MD
simulations show that ibuprofen and warfarin association to the secondary fatty acid (FA) binding site 2 (FA2) induces a
reorientation of domain I of HSA-heme-Fe(III), this leads to the redirection of the His146 residue providing an additional
bond to the heme-Fe(III) atom, providing the 5
+
1 configuration. The comparison of Fe-K edge XANES spectra calculated
using MD structures with those obtained experimentally confirms the reliability of the proposed structural model. As a
whole, combining XAS and MD simulations it has been possible to provide a reliable model of the heme-Fe(III) atom
coordination state and to understand the complex allosteric transition occurring in HSA-heme-Fe(III) upon ibuprofen and
warfarin binding
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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