Function complexation

As research reveals the ultrastructural organization of the cell in ever greater detail, more and more of the so-called soluble enzyme systems are found to be physically united into functional complexes. Thus, in many (perhaps all) metabolic pathways, the consecutively acting enzymes are associated into stable multienzyme complexes that are sometimes referred to as metabolons, a word meaning units of metabolism. ... 

A wide diversity of herbal remedies have purported abilities to stimulate defense functions. Complexes of carbohydrate and lignin, which are present in some herbs, modulate enteric immune functions (Kiyohara et al, 2000), and the changes in cytokine secretion (Matsumoto and Yamada, 2000) can trigger systemic responses. The polysaccharides present in other herbal medicines augment production of immunoglobulin (Ig) A by the Peyer s patches in the small intestine (Sakushima et al, 1997 Yu et al, 1998). The responses of the enteric immune system to lectins are variable (Pusztai 1993), and can elicit systemic responses (Lavelle et al, 2000). Other phytochemicals provide protection by inducing detoxification pathways in mucosal cells (Williamson et al, 1998). 

Facilitate pre-vulcanisation processing, increase softness, extensibility and flexibility of the vulcanised end-product. The rubber processing industry consumes large quantities of materials which have a plasticising function complex mixtures (paraffinic, naphthenic, aromatic) of mineral hydrocarbon additives, used with the large tonnage natural and synthetic hydrocarbon rubbers, are termed process oils. Because of the complexity of these products, precise chemical definition is usually not attempted. If the inclusion of an oil results in cost reduction it is functioning as an extender. The term plasticiser is commonly reserved for synthetic liquids used with the polar synthetic rubber. 

The second approach consists of synthesizing first the complex MLra 1(L X) with the desired ratio (L )/(M) this complex bears the reactive fragment X which then reacts with the surface of the silica. This method is of limited interest, because the synthesis and isolation of these functionalized complexes is not straightforward. One of the successful examples concerns the synthesis of nickel carbonyl complexes anchored to the surface via two bonds in an attempt to increase the stability through a sort of chelate effect. Initial attempts to achieve this by the methods described in Equation(5) (initial functionalization of silica) and Equation(6) (initial functionalization of complex) failed, as demonstrated by 29Si and 31P CP MAS NMR spectroscopies.51... 

Only when the solution of the functionalized complex is added dropwise to silica is the desired di-anchored complex formed (Equation(7)). 

The noncovalent approach is based on the use of complexes containing suitable moieties which are able to recognize specific proteins, primarily human serum albumin (HSA). When the targeting protein is confined in the blood, the adduct between the serum albumin and the functionalized complex may function as a blood pool agent. Due to the reversible nature of binding between the protein and the paramagnetic chelate, these adducts maintain excretory pathways typical of small complexes which, from the pharmacological point of view, favors them over covalently bound macromolecules. 

Another reason for complexity of cell-activation mechanisms resides in the end response of neutrophils - that is, the delivery of cytotoxic products. Whilst these products are highly lethal towards pathogens, they can also attack and destroy host tissues, and this can have deleterious effects on tissue function. Complex intracellular signalling mechanisms to activate these cytotoxic pathways also guards against non-specific activation, which could lead to host tissue damage. 

Farquhar MG and Palade GE [1963] functional complexes in various epithelia. 1 Cell Biol 17 375 112... 

Ollagnier-de-Choudens S, Mattioli T, Takahashi Y, Fontecave M. 2001. Iron-sulfur cluster assembly. Characterization of IscA and evidence for a specific functional complex with ferredoxin. J Biol Chem 276 22604-7. 

This same reaction has been applied to the synthesis of chiral functional complexes. ... 

Table 2. Content of fatty acids and lipids in the Multi-Nutrient-Functional Complex (MNFC) Grinization , in percentage.

The mechanistically and functionally complex N-end rule pathway (Fig. 2) is but one of many distinct pathways of the Ub system. The vast functional range of this system stems from the enormous diversity of its physiological substrates. In other words, it is the constitutive or conditional degradation of many specific proteins (cyclins, transcription factors, components of signal transduction pathways, damaged proteins) by ubiquitin-dependent pathways that underlies the involvement of the Ub system in just about every biological circuit in a living cell (5, 6, 9). 

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