Proteosynthesis vs. Proteolysis: How to Bias This Antagonism in Favor of Proteosynthesis
Willi Kullmann in Enzymatic Peptide Synthesis, 1987
In a figurative sense, the precipitation of insoluble peptides can be considered as a “product-trapping” method. An alternative technique that has been used in preference during protein semisyntheses (see Chapter 10) profits from the presence of a specific molecular trap capable of specifically scavenging the desired products. In practice, a newly synthesized peptide is noncovalently bound (trapped) by another peptide or protein to form a stable complex. This approach does not basically differ in principle from previously mentioned methods since the energy-releasing process of product chelation can significantly overcompensate for the energy-consuming process of peptide bond formation. The “trapping agents” need not be exclusively peptidic in nature, for example as protease inhibitors, antibodies, or receptors and the like. In fact, any substance capable of forming an intra- or intermolecular complex with the reaction product, but not with the educts. may act as a scavenger.14
Animals on the Land
Joyce D’Silva, John Webster in The Meat Crisis, 2017
The number of studies on the relationships between grazing livestock systems and biodiversity is increasing quickly in recent years (Rodríguez-Ortega et al., 2014). Biodiversity-related conflicts in Europe are caused by two main processes: intensification of agriculture linked to changing scale of operations and abandonment of HNV farmlands (Henle et al., 2008). The current process of encroachment of vegetation as consequence of a reduction in traditional extensive grazing is causing a decline in species with an unfavourable conservation status in Europe. For example, Fonderflick et al. (2010) establishes a clear relationship between landscape changes in Mediterranean upland pastoral systems and bird populations. In the case of spiders, rare or specialist species are often replaced by generalists or species associated to forested areas (Oxbrough et al., 2006). Additionally, the distribution of some scavenger species (vultures) shows a strong spatio-temporal link with pastoral areas, as there is a direct dependency on the carcasses of the grazing domestic animals they feed on (Olea and Mateo-Tomas, 2009). In summary, most studies agree on the general importance of grasslands agroecosystems for the conservation and management of biodiversity. However, relationships between grazing animals, pasture management and the richness of plant and animal species are complex and concern various spatial and temporal scales, so further research is needed.
The Human Immune System May Protect against HIV
Omar Bagasra, Donald Gene Pace in A Guide to AIDS, 2017
Part of the fascinating work that the innate immune system performs is done by useful cells that used to be called scavenger cells (mostly neutrophils, eosinophils, basophils, and macrophages). These scavengers have evolutionarily learned to sense dangerous molecules, and then overwhelm them. They have evolutionary memory and not only know what is foreign, but also what is perilous. Just as not all immigrants are criminals, but some are, the scavenger cells learn to sense both foreignness and peril. Food, for example, would typically not be regarded as dangerous, even though it is foreign, similar to migrant workers who help us harvest the crops. The scavenger cells help tidy the body up, to keep it free of pathogens and other unwanted clutter. As one can guess, this is one of the oldest immune systems and has been estimated to be more than 3 billion years old.
Nanoliposomes encapsulation of enriched phenolic fraction from pistachio hulls and its antioxidant, anti-inflammatory, and anti-melanogenic activities
Published in Journal of Microencapsulation, 2020
Ehsan Oskoueian, Ehsan Karimi, Reza Noura, Mahdi Ebrahimi, Negin Shafaei, Ensiyeh Karimi
The inflammation is a complex, well-orchestrated and considered as a protective process regulated by the release of various cellular and chemical mediators. In the presence of inflammation, the cellular production of ROS increases and may disrupt the cell function. The nitric oxide is a reactive nitrogen species (RNS) produced upon the activity of inducible nitric oxide synthase (iNOS) and is expressed primarily in macrophages after stimulation by LPS/INF-γ. To maintain the cellular metabolic activity and alleviate the inflammation, the free radicals are contracted via antioxidant enzymes such as superoxide dismutase, catalase, and the glutathione peroxidase and other antioxidants such as bioactive phytochemicals and vitamins provided from dietary sources. The PEF-NLs appeared to be the good NO scavenger (Table 2) since the IC50 value was below 200 µg/ml according to Tsai et al. (2007) classification for NO scavengers. In addition, the PEF-NLs is considered as strong inhibitors of NO production in LPS/IFN-γ stimulated RAW 264.7 cell lines (Figure 3(b)). The results revealed that the PEF-NLs not only directly scavenged the free radicals but also suppressed the iNOS, COX-2, and NF-κB as pro-inflammatory genes. Thus, the PEF-NLs acted through a different mechanism in modulating inflammation. The anti-inflammatory activity observed in the pistachio hulls observed in this study was consistent with the results reported by Grace et al. (2016a).
Polyethyleneglycol-serine nanoparticles as a novel antidote for organophosphate poisoning: synthesis, characterization, in vitro and in vivo studies
Published in Drug and Chemical Toxicology, 2023
Pedram Ebrahimnejad, Ali Davoodi, Hamid Irannejad, Javad Akhtari, Hamidreza Mohammadi
This study revealed that the mortality rate in poisoned mice significantly decreased (25%) after treatment with PEG-NPs. In contrast, PAM alone could not improve the survival rate of DZ-poisoned mice as observed by nanoparticles, thus confirming the unique structure of PEG-NPs in DZ poisoning applications. Unlike the existing antidote for OP poisoning therapies which block ACh receptors or compete with ACh, the PEG-NPs act as an OP trap and/or reactive agent of ChE enzymes and are therefore less expected to induce anticholinergic side effects. Also, the exclusively biodegradable nature and biocompatible of the synthesized PEG-NPs diminishes safety concerns related to nanomaterial applications. The distinctive bio-scavenger approach using polymeric NPs may open a gate to new strategies in eliminating chemical and organic toxicants.
“Parent Advocacy” as an Ideological Code: LGBTQ Parents Engage with Disability Services
Published in Journal of Progressive Human Services, 2019
The search for information, services, and referrals forms a central piece of the systemwork parents engage in. As one parent recounted, “Finding the right services – it’s like a scavenger hunt, man. It’s not easy to do, even when a service is out there.” Almost every participant talked extensively about this type of “scavenger hunt,” but one in which the list of services that are “out there” is uncertain and changeable. This hunt is an area of parental systemwork that remains unseen by most providers. By the time that parents had come face to face with a disability service provider, they told me that they had already engaged in months or years of researching, thinking, deciding, and waiting. The hunt did not end with engaging with a particular organization or professional since new needs or services might always be required. For example, Debbie described an ongoing and open-ended self-“education” process as an integral part of parenting and advocacy: Anyone I come into contact with I kind of pick their brain and just shelve that information because who knows, maybe in ten years I might need that information or, it might be useful… [because] my kid is [a young age], he can’t really advocate for himself. I have got to advocate for him. For whatever he needs, he might need now or later, so I can’t really do that unless I’m educated, I think.
Related Knowledge Centers
- Carbon Monoxide
- Chemistry
- Hydrocarbon
- Hydrogen Sulfide
- Hydroxyl Radical
- Methane
- Sulfur Dioxide
- Atmospheric Chemistry
- Radical
- Photodissociation