Myristic acid, structure

Soaps are composed of sodium salts of various fatty acids. These acids include those with the general structure CH3-(CH2) -COOH where n = 6 (caprylic acid), 8 (capric acid), 10 (lauric acid), 12 (myristic acid), 14 (palmitic acid), and 16 (stearic acid). Oleic acid (CH3-(CH2)7-CH=CH-(CH2)7-COOH) and linoleic acid (CH3-(CH2)4-CH=CH- H2-CH=CH-(CH2)7-COOH) are also common soap ingredients. These sodium salts readily dissolve in water, but other metal ions such as Ca2+ and Mg2+ form precipitates with the fatty acid anions. For example, the dissolution of the sodium salt of lauric acid and the subsequent formation of a precipitate of the lauric acid anion with calcium ion is given by... 

Figure 11.1 Structures of commonly occurring saturated fatty acids (i) myristic acid, Ci4 o (ii) palmitic acid, C s-.o (iii) stearic acid, Ci8 0.

Endothelial NOS was found to be associated with cell membranes and this property was associated with the finding that the cDNA contained the structure for binding myristic acid55. Busconi and Michel56 used bovine aortic endothelial cells to demonstrate that the myristoylated protein was found. When the second amino acid, glycine, was converted to alanine, the addition of myristic acid was prevented and the enzyme remained soluble. Sessa and coworkers51 carried out the same experiments simultaneously and found the same results. However, in both cases the enzyme was not purified, although the protein... 

N-Myristoylation is achieved by the covalent attachment of the 14-carbon saturated myristic acid (C14 0) to the N-terminal glycine residue of various proteins with formation of an irreversible amide bond (Table l). 10 This process is cotranslational and is catalyzed by a monomeric enzyme called jV-myri s toy 11ransferase. 24 Several proteins of diverse families, including tyrosine kinases of the Src family, the alanine-rich C kinase substrate (MARKS), the HIV Nef phosphoprotein, and the a-subunit of heterotrimeric G protein, carry a myr-istoylated N-terminal glycine residue which in some cases is in close proximity to a site that can be S-acylated with a fatty acid. Functional studies of these proteins have shown an important structural role for the myristoyl chain not only in terms of enhanced membrane affinity of the proteins, but also of stabilization of their three-dimensional structure in the cytosolic form. Once exposed, the myristoyl chain promotes membrane association of the protein. 5 The myristoyl moiety however, is not sufficiently hydrophobic to anchor the protein to the membrane permanently, 25,26 and in vivo this interaction is further modulated by a variety of switches that operate through covalent or noncovalent modifications of the protein. 4,5,27 In MARKS, for example, multiple phosphorylation of a positively charged domain moves the protein back to the cytosolic compartment due to the mutated electrostatic properties of the protein, a so-called myristoyl-electrostatic switch. 28 ... 

The myristoyl moiety attached to VP4 is observed in the poliovirus structures. This moiety is in close association with the cylinder formed by VP3 [19]. In HRVs, density consistent with the myristoyl moiety is also seen near the P cylinder [25]. In the HRVs, structural disorder of the first 25-28 N-terminal residues of VP4 obscures the connection between VP4 and the myristoyl group. The addition of myristic acid to protein is seen in many viral and cellular... 

Draw the structure of glycerol myristate, a fat made from glycerol and three myristic acid molecules (see Table 24.3). 

When metals are available, the laminae are stabilized by bonding forces as shown in studies on phospholipid-water systems59. Even films of myristic acid and metal ions are solid up to a cross-section area of 50 A per molecule60,61. The numerous phase transitions of pure phospholipid-water systems62 and the polymorphism of phospholipid crystals63 suggest that even pure phospholipid bilayers — in their true nature — do not represent stable lattice structures but require metal ions for coordina-tive purposes. 

The hydrophobic lipid anchors can be either fatty chains (e.g. derived from oleic or myristic acid) or a cholesterol group. Lipid anchors help in forming liposomes (or micellar structures) and determine the physical properties of a lipid bilayer, such as membrane rigidity and rate of lipid exchange between lipid... 

Jojoba (Simmondsia chincnsis) This is not actually an oil but a liquid wax. It is good for cosmetic use with moisturizing properties and ideal for dry skin and conditions like eczema and psoriasis. It is similar chemically to sebum and able to dissolve it. The oil keeps well owing to a stable molecular structure and analysis shows both saturated and unsaturated fatty acids, with eicosenoic (71%), oleic (14%), stearic (10%) and palmitic (1.5%). The presence of a compound called myristic acid is thought to confer anti-inflammatory properties. 

Trimyristin, a solid fat present in nutmeg, is hydrolyzed to give one equivalent of glycerol and three equivalents of myristic acid. Give the structure of trimyristin. 

Fig. 1. Chemical structure of phosphonolipids (1) and arsonolipids (2). Arsonolipids (Ars) with R = lauric acid (Cl 2) myristic acid (Cl 4) palmitic acid (C16), and stearic acid (Cl 8) were used for ARSL construction...

Figure 23.12 depicts the subunit structure of G proteins and their interactions, as affected by GTP and GDP. Several different forms of each G protein are known. In most forms, the 1 subunit is prenylated (covalently bound to a 20 carbon isoprenoid moiety at the C-terminal cysteine). The ot subunit is covalently linked to myristic acid and is the subunit that contains both the guanine nucleotide-binding site and the GTPase activity. 

The lipopolysaccharide (LPS) component of the outer cell membranes of brucellae is quite different—both structurally and functionally—from that of other Gram-negative organisms.11,12 The lipid A portion of a Brucella organism LPS contains fatty acids 16 carbons long, and lacks the 14-carbon myristic acid typical of lipid A of Enterobacte-riaceae. This unique structural feature may underlie... 

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