Containment/mediation mechanisms

LOXs are proteins containing a single atom of nonheme iron in catalytic center, with the ferric enzyme in an active form. The free radical-mediated mechanism of LOX-catalyzed process may be presented as follows (see also Figure 26.1) ... 

Mucosal biopsy specimens from patients with asthma contain lymphocytes, many of which express surface markers of inflammation. There are two types of T-helper CD4-F cells. Type 1 T-helper (Thl) cells produce IL-2 and interferon-y (IFN-y), both essential for cellular defense mechanisms. Th2 cells produce cytokines (IL-4, -5, -6, -9, and -13) that mediate allergic inflammation. It is known that Thl cytokines inhibit the production of Th2 cytokines, and vice versa. It is hypothesized that allergic asthmatic inflammation results from a Th2-mediated mechanism (an imbalance between Thl and Th2 cells). ... 

Interestingly, the amino-terminal extensions contain putative nuclear localization sequences that appear to be involved in transport of these proteins into the nucleus (Acland et al., 1990 Amalric et al., 1991 Bugler et al., 1991 Kiefer et al., 1994). FGF-1 has also been shown to enter the nucleus, but the amino acid sequence involved in this process remains to be elucidated (Cao et al., 1993). The specific function of nuclear FGF is still unclear, but there is evidence that FGF-2 import into the nucleus is involved in the mitogenic response of endothelial cells to FGF (Bouche et al., 1987 Baldin et al., 1990). Such a nuclear mechanism of FGF action could supplement the classical signal pathway by receptor-mediated mechanisms. 

A drug often encounters several cell membranes before it reaches the biophase and other parts of the organism, e.g. the elimination sites. Cellular membranes are composed of an lipoidal matrix covered on both sides by proteins. Cell membranes contain small pores, and between cells narrow, water-filled chaimels exist. Dmgs cross membranes by passive or, in some cases, carrier-mediated mechanisms. 

Plant defensins, antifungal peptides which are not related to mammalian or insect defensins. The plant cc-defensins are present in seeds or leaves and are characterized by complex structures. They contain disulfide-linked cysteines in a triple-stranded antiparallel /3-sheet with only one cf-helix, and are homologous to those produced in human and rabbit neutrophils. Plant Q -defensins are not capable of forming ion-permeable pores in artificial membranes, but they may act through a receptor-mediated mechanism. They are considered PR proteins and are classified as members of the PR-12 group [K. Thevissen et al., J. Biol. Chem. 1996, 271,15018 A. J. De Lucca etal.. Can.]. Microbiol. 2005, 51,1001]. 

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