Lipids biological functions

Kaprelyants, A., Suleimenov, M., Sorokina, A., Deborin, G., El-Registan, G., Stoyanovich, F., Lille, Yu., Ostrovsky, D. Structural-functional changes in bacterial and model membranes induced by phenolic lipids. Biological membranes, Vol.4, No.3, (March 1987), pp. 254-261, ISSN 0748-8653... 

Subczynskil, W.K. and Wisniewska, A. (2000) Physical properties of lipid bilayer membranes relevance to membrane biological functions. Acta Biochimica Polonica, 47 (3), 613-625. 

Scheme 11. Variation of S-lipidation of palmitoylatable amino acid residues for the investigation of the biological function of protein lipidation...

So far GPI biosynthesis raises many questions as its correct regulation is crucial for viability in yeast and for embryonic development in mammals. Many steps remain unclear, also due to the fact that most of the proteins involved still have to be characterized. The same is true for the biological function of the GPI anchor apart from membrane insertion. Several suggestions have been made according to which GPI anchors are targeting lipid rafts, specific intracellular compartments, or the apical membrane of polarized epithelial cells. 

Very little is known about the motions of lipid bilayers at elevated pressures. Of particular interest would be the knowledge of the eifect of pressure on lateral diifusion, which is related to biological functions such as electron transport and some hormone-receptor interactions. However, pressure eifects on lateral diifusion of pure lipid molecules and of other membrane components have yet to be studied carefully. 

Figure 8.9 Prostaglandins and leukotrienes are potent eicosanoid lipid mediators, derived from phospholipase-released arachidonic acids, that are involved in numerous homeostatic biological functions and inflammation. They are generated by cyclooxygenase isozymes and 5-lipoxygenase, respectively, and their biosynthesis and pharmacological actions are inhibited by clinically relevant nonsteroidal anti-inflammatory drugs.

Hosokawa, M. (2004). Chapter 10. Improvement of biological response of cells by marine lipids. In "Suisangaku-shirizu Marine Functional Lipids Sources, Functionalities, and Applications", (K. Takahashi, Ed.), Vol. 142, pp. 145-155. Kouseisha Kouseikaku, Tokyo (in Japanese). 

In this chapter we first describe the composition of cellular membranes and their chemical architecture— the molecular structures that underlie their biological functions. Next, we consider the remarkable dynamic features of membranes, in which lipids and proteins move relative to each other. Cell adhesion, endocytosis, and the membrane fusion accompanying neurotransmitter secretion illustrate the dynamic role of membrane proteins. We then turn to the protein-mediated passage of solutes across membranes via transporters and ion channels. In later chapters we discuss the role of membranes in signal transduction (Chapters 12 and 23), energy transduction (Chapter 19), lipid synthesis (Chapter 21), and protein synthesis (Chapter 27). 

Triacylglycerols and the ether lipids described in the previous section are classified as neutral lipids. Other neutral lipids are alcohols, waxes, aldehydes, and hydrocarbons derived from fatty acids. These sometimes have specific biological functions. For example, fatty aldehydes are important in the bioluminescence of bacteria (Eq. 23-47). 

Quantitatively minor membrane components with important biological functions include ubiquinone, which is present in the inner mitochondrial membrane, and the tocopherols. Plant chloroplast membranes contain chlorophyll, carotenes, and other lipid-soluble pigments. 

The biological function of the tocopherols is still a matter of discussion (83MI22400). They behave as antioxidants (68MI22401), protecting the lipids in plants from excessive oxidation,... 

Since the start of the twentieth century, steroids have continued to be the focus of the research activities of natural product chemists, synthetic chemists, biochemists and clinicians. The reasons are several-fold and related to the fascination of the chemical complexity of sterols and their biochemical functions in living organisms. Sterols and steroids are excellent compounds for the organic chemists to practise their skills upon in the development of new reactions and synthetic procedures. The biological functions of sterols, for example as an essential constituent of membranes, have proved thought-provoking to lipid biochemists. 

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