Proteins acylation

Towler, D. A., Gordon, J. L, Adams, S. R, and Glaser, L., 1988. The biology and enzymology of eukaryodc protein acylation. Annual Review of Biochemistry 57 69—99. 

Gene activated Lipoprotein lipase fatty acid transporter protein adipocyte fatty acid binding protein acyl-CoA synthetase malic enzyme GLUT-4 glucose transporter phosphoenolpyruvate carboxykinase... 

An affinity label is a molecule that contains a functionality that is chemically reactive and will therefore form a covalent bond with other molecules containing a complementary functionality. Generally, affinity labels contain electrophilic functionalities that form covalent bonds with protein nucleophiles, leading to protein alkylation or protein acylation. In some cases affinity labels interact selectively with specific amino acid side chains, and this feature of the molecule can make them useful reagents for defining the importance of certain amino acid types in enzyme function. For example, iodoacetate and A-ethyl maleimide are two compounds that selectively modify the sulfur atom of cysteine side chains. These compounds can therefore be used to test the functional importance of cysteine residues for an enzyme s activity. This topic is covered in more detail below in Section 8.4. 

McLihnney, R. 1990. The fats of life the importance and function of protein acylation. Trends in Biochemical Sciences 15, 387-391. 

It has recently been demonstrated (191) that the nature and location of lipid A primary fatty acids is determined by the specificity of the enzymes UDP-GlcpNAc-G-acyltransferase and UDP-3-6>-[(i )-hydroxyacyl]-GlcpN-N-acyltransferase for acyl - acyl carrier protein (acyl ACP). The analysis of the acyl ACP specificity of these O- and A-acyltransferases should, therefore, constitute a biochemical approach for elucidation of the location of primary fatty acids in lipid A (191). 

Thioesters play a paramount biochemical role in the metabolism of fatty acids and lipids. Indeed, fatty acyl-coenzyme A thioesters are pivotal in fatty acid anabolism and catabolism, in protein acylation, and in the synthesis of triacylglycerols, phospholipids and cholesterol esters [145], It is in these reactions that the peculiar reactivity of thioesters is of such significance. Many hydrolases, and mainly mitochondrial thiolester hydrolases (EC 3.1.2), are able to cleave thioesters. In addition, cholinesterases and carboxylesterases show some activity, but this is not a constant property of these enzymes since, for example, carboxylesterases from human monocytes were found to be inactive toward some endogenous thioesters [35] [146], In contrast, allococaine benzoyl thioester was found to be a good substrate of pig liver esterase, human and mouse butyrylcholinesterase, and mouse acetylcholinesterase [147],... 

Phosphopantetheine tethering is a posttranslational modification that takes place on the active site serine of carrier proteins - acyl carrier proteins (ACPs) and peptidyl carrier proteins (PCPs), also termed thiolation (T) domains - during the biosynthesis of fatty acids (FAs) (use ACPs) (Scheme 23), polyketides (PKs) (use ACPs) (Scheme 24), and nonribosomal peptides (NRPs) (use T domain) (Scheme 25). It is only after the covalent attachment of the 20-A Ppant arm, required for facile transfer of the various building block constituents of the molecules to be formed, that the carrier proteins can interact with the other components of the different multi-modular assembly lines (fatty acid synthases (FASs), polyketide synthases (PKSs), and nonribosomal peptide synthetases (NRPSs)) on which the compounds of interest are assembled. The structural organizations of FASs, PKSs, and NRPSs are analogous and can be divided into three broad classes the types I, II, and III systems. Even though the role of the carrier proteins is the same in all systems, their mode of action differs from one system to another. In the type I systems the carrier proteins usually only interact in cis with domains to which they are physically attached, with the exception of the PPTases and external type II thioesterase (TEII) domains that act in trans. In the type II systems the carrier proteins selectively interact... 

Recently, the purification of recombinant protein acyl transferases was published. Future investigations will show whether these biocatalysts may also serve as tools for acylating proteins. Depending on their substrate tolerance the incorporation of non-natural acyl analogues could also be possible. 

Towler DA, Gordon , Adams SP, Glaser L. The biology and enzymology of eukaryotic protein acylation. Annu Rev Biochem 1988 57 69-99. 

P. J. Swart, M. E. Kuipers, C. Smit, R. Pauwels, M. de Bethune, E. De Clercq, H. Huisman, and D. K. F. Meijer, Antiviral effects of milk proteins Acylation results in polyanionic compounds with potent activity against human immunodeficiency virus type 1 and 2 in vitro, AIDS Res. Hum. Retroviruses 72 769-775 (1996). 

The most thorough investigation in this area was that of Harrison and Royle43 on astatination of rabbit immunoglobulin (IgG) which could be used in animal experiments. PAtBA was produced with > 90% radiochemical yield, and a reproducible overall yield of > 30% for labelled protein was obtained with negligible deastatination of the latter in vivo. These favourable results could be achieved most probably due to the fact that the PAtBA was prepared without an iodine carrier and that the micro amounts of the product were purified from the macro amounts of contaminates by HPLC. To bind PAtBA to the protein, acylation with mixed anhydride was used. Preparation of the mixed anhydride 7 (equation 5) could be carried out in about 20 minutes at ca 0 °C. For astatination rabbit IgG protein is dissolved in borate buffer (pH = 9.3) and then added to 7 (see equation 6) the procedure takes about 1 hour at ca 15 °C. The astatinated protein is separated from non-conjugated materials by gel filtration and eluted from the column by phosphate-buffered saline. 

Friedman, M. (1978). Inhibition of lysinoalanine synthesis by protein acylation. In "Nutritional improvement of Pood and Peed Proteins , M. Friedman, Ed., Plenum Press, New York, pp. 613-648. 

Acyl carrier protein Acyl transferase Malonyl transferase Co-enzyme A... 

Straub, S. G., Yajima, H., Komatsu, M., Aizawa, T., Sharp, G. W. G. (2002). The effects of cerulenin, an inhibitor of protein acylation, on the two phases of glucose-stimulated insuhn secretion. Diabetes 51(Suppl 1) S91-S95. 

The next step in the pathway is the linking of malonyl-CoA and acetyl-CoA to different molecules of another sulphydryl containing protein, acyl carrier protein (ACP). It is on their ACP derivatives that malonyl-CoA and acetyl-CoA combine to give the -keto acid acetoacetic acid, still linked to ACP, but releasing CoA and C02. 

ACTH adrenocorticotrophic hormone, actin cytoskeletal protein, acyl group such as acetyl, propionyl, etc. acylation addition of an acyl group. 

In contrast, CYP2B1-catalyzed addition of the activated oxygen to the internal rather than terminal triple bond carbon of phenylacetylene results in heme X-alkylation rather than protein acylation (see below) Predominant inactivation of CYP2B1 by phenylacetylene via heme alkylationand by 2-ethynylnaphthalene via protein acylation sheds some light on the influence exerted by the fit of the inhibitor within the active... 

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