Killer structures

Romer, L., C. Klein, A. Dehner, H. Kessler, and J. Buchner. 2006. p53—a natural cancer killer Structural insights and therapeutic concepts. Angew Chem Int Ed Engl 45(39) 6440-60. 

A non-Humean response is to maintain that state and event types have at least some of their causal powers essentially, namely, the (conditional) powers to produce their manifestations. I will not attempt to determine here whether we should be Humeans or non-Humeans about causation. Suffice it for the moment just to note that even if event types endow causal powers essentially, the question remains whether functional state and event types endow causal powers. Thus, suppose that the Humean view is indeed wrong, and that some structures are essentially killer structures, and so essentially endow the power to kill. The question would still remain why the state of having some or other killer structure is a state that is itself a killer state - a state that endows the power to kill — given that it is not identical with any of the killer structures. Why think that the property of having some property or other that essentially endows the power to kill is itself a property that endows the power to kill Similarly, even if all the bases or core realizers of a functional property, water solubility, essentially endow the (conditional) power to cause dissolvings in water, what reason is there to think that the functional property does - that water solubility itself does For the moment, suffice it to note that these questions deserve answers. 

Fig. 14 (A) EGFP structure. Mutations made from the GFP are highlighted, (PDB ID 2Y0G) (B) KillerRed structural model (PDB ID 3GB3) (G) TagRFP structure and chro-mophore (PDB ID 3M22) (D) SuperNova structure, Mutations made from KillerRed are highlighted, (PDB ID 3WCK).

It is essential for viruses to penetrate the cells of an infected host in order to subvert the cells replicative machinery towards viral replication. Clearly, it is in the interests of the host to kill such infected cells before the virus has had a chance to reproduce. Natural killer (NK) cells are cytotoxic cells that appear to have evolved to carry out just such a task. The precise lineage of NK cells is still uncertain. They are large granular lymphocytes that attach themselves to structures, presumably glycoproteins, that appear on the surface of virally infected... 

Interferons There are two types of interferons Type I, which includes IFN-a and IFN-jS, and Type II consisting of IFN-y. IFN-a and IFN- 8 have about 30% homology in amino acid sequence. There are two more recently discovered Type I interferons they are called IFN-o and IFN-t. IFN-a and IFN- 8 each have 166 amino acids, and IFN-yhas 143. Both IFN-a and IFN-jS are of single chain structure and bind to the same type of cell surface receptors, whereas IFN-y is a dimer of two identical chains and interacts with another type of receptor. All our cells can produce Type I interferons when infected by viruses, bacteria, and fungi. However, only T cells and natural killer cells can produce... 

Sun P-D Structure and function of natural-killer-cell receptors. Immunol Res 2003 27 539-548. 

Morphine was known to the Sumerians and Egyptians as a very valuable pain killer in medicine it is also a powerful narcotic that is habit forming. A great deal of effort has been spent in finding a derivative of morphine that has its good properties, and less of its bad properties. Then, in 1944, demerol and methadone were discovered, which are even more powerful than morphine, but bear no structural relation to morphine. The leading theory now is that both morphine and methadone have the same T-shape, and may fit the receptor. 

Sequence Determination of the Brain Peptide Leucine Enkephalin A group of peptides that influence nerve transmission in certain parts of the brain has been isolated from normal brain tissue. These peptides are known as opioids, because they bind to specific receptors that also bind opiate drugs, such as morphine and naloxone. Opioids thus mimic some of the properties of opiates. Some researchers consider these peptides to be the brain s own pain killers. Using the information below, determine the amino acid sequence of the opioid leucine enkephalin. Explain how your structure is consistent with each piece of information. 

Serotonin appears to be involved in activation of pain fibers, when tissues are injured. Cocaine (Fig. 30-28) is a powerful pain killer and a weak antagonist of responses to serotonin, a fact that has led to the synthesis of new antagonists, such as the one in Fig. 30-28 whose structure encompasses that of both cocaine and serotonin.779 781 It is active at a concentration as low as 10 11 M and is among the most potent known drugs of any type. 

It is the anchoring molecules (that strangely enough biologists call accessory proteins) that determine the form that cells have in space and the movements that they perform. The best proof of this enormous versatility is the fact that the cytoskeleton was invented by unicellular eukaryotes, but later was exploited by metazoa to build completely new structures such as the axons of neurons, the myofibrils of muscles, the mobile mouths of macrophages, the tentacles of killer lymphocytes and countless other specialisations. 

Borrego, F., Rabat, J., Kim, D.-K., Lieto, L., Maasho, K., and Pena, J. et al. (2002). Structure and function of major histocompatibility complex (MHC) class I specific receptors expressed on human natural killer (NK) cells. Mol. Immunol. 1063, 1-24. 

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