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Subject threonine

In addition, eNOS is subject to protein phosphorylation. It can be phosphotylated on several serine (Ser), threonine (Thr), and tyrosine (Tyr) residues however, major changes in enzyme function have been reported for the phosphorylation of amino acid residues Seri 177 and Thr495 (in the human eNOS sequence) (Fig. 3). [Pg.866]

The phosphonium and carbenium salts are efficient reagents for activating and coupling A-alkoxycarbonylamino acids as well as peptide acids. However, the requirement for tertiary amine to effect the reaction has several implications. The base renders hydroxyl groups subject to acylation. Hence, the side chains of serine and threonine and any hydroxymethyl groups of a resin that have not been derivatized... [Pg.229]

Only three amino acids have a hydroxyl functional group in their side chain tyrosine, serine and threonine. Some kinases target only tyrosine residues (tyrosine kinases) whereas others may phosphorylate serine or threonine (Ser/Thr kinases). An enzyme protein (the substrate for the kinase) may have several tyrosine, serine or threonine residues within its primary sequence, but only some of these are subject to phosphorylation by a particular kinase (see Figure 3.6)... [Pg.65]

The peptidases were separated into catalytic types according to the chemical nature of the group responsible for catalysis. The major catalytic types are, thus, Serine (and the related Threonine), Cysteine, Aspartic, Metallo, and As-Yet-Unclassified. An in-depth presentation of catalytic sites and mechanisms, based on this classification, is the subject of Chapt. 3. [Pg.33]

Proteasome and RC subunits are subjected to a variety of post-translational modifications including phosphorylation, acetylation, myristoylation, and even O-glycosylation [136-140]. In yeast all seven a-subunits are acetylated as well as two yS-subunits. Since acetylation of the N-terminal threonine in an active j8-subunit would poison catalysis, it has been suggested that the propeptide extensions function to prevent acetylation [130]. Three members of the S4 ATPase subfamily (S4,... [Pg.235]

Phosphorylation of serine or threonine residues involves an ATP-dependent addition of a phosphate group to a primary (serine) or secondary (threonine) alcohol. Phos-phorylated proteins are often subject to rapid degradation. [Pg.110]

In glycoproteins containing a carbohydrate-L-serine linkage, such as 50, or a carbohydrate-L-threonine linkage, the carbohydrate is released from tire protein on treatment with base. The carbohydrate released is then subjected to further degradation, until an alkali-stable structure is formed. This reaction was used by Kabat, Lloyd,... [Pg.213]

To a solution of L-threonine allyl ester hydrochloride [22,42] (6.0 g, 30.6 mmol, the corresponding hydrotrifluoroacetate or hydrotoluenesulfonate can also be used) in saturated NaHCOj solution (100 mL) and dioxane (100 mL) is added dropwise at 0°C a solution of 9-fiuorenylmethyl chloroformate (10.8 g, 41.8 mmol) in dioxane (50 mL). After stirring for 24 h, the solvent is evaporated in vacuo, the remainder dissolved in ethyl acetate (200 mL), washed with 0.5 N HC1, saturated NaHCOj solution, and water (each 100 mL), dried with MgS04, and concentrated in vacuo. The crude product is subjected to chromatography on silica gel (300 g) in petroleum ether-ethyl acetate (4 1), and the obtained product is recrystallized from ethyl acetate-petroleum ether to give pure 24 yield, 11.2 g (96%) mp 98°-100°C [a]D -17.2° (c 1, dimethylformamide) R, 0.33 (petroleum ether-ethyl acetate 2 1). [Pg.276]

Buerger K, Teipel SJ, Zinkowski R, et al. CSF tau protein phosphorylated at threonine 231 correlates with cognitive decline in MCI subjects. Neurology 2002 59(4) 627-629. [Pg.127]

Immobilization of enzymes. Enzymes consist of amino acids which contain reactive groups such as amino(lysine, c-terminus), thiol (cysteine), carbonyl (aspartate, glutamate and c-terminus), aromatic hydroxyl (tyrosine) and aliphatic hydroxyl (serine and threonine). Chemical, ionic or chelation reactions with such groups can enable us to attach the amino acids and hence proteins to insoluble, inert supports. Immobilization is one of the best ways of stabilizing enzymes. There is a vast literature on this subject and the reader is directed to Barker (9) and Goughian et al (10) for further reading on specific systems, techniques and applications of immobilization. [Pg.48]

Other conversions to unnatural residues occur when most proteins are exposed to high pH (80, 81,82). The high pH causes a -elimination of a cystine (see Figure 16) or O-substituted serine or threonine, with the formation of a dehydroalanine or a dehydro-a-aminobutyrate. Such products are subject to nucleophilic attack by the e-amino group of a lysine to form a cross-linkage, such as lysinoalanine, or attack by cysteine to form lanthionine. Walsh et al. (81) have taken advantage of the formation of these cross-links to produce avian ovomucoids that have nonreducible cross-links and have lost the antiprotease activity of one of their two inhibitory sites (see Figure 17). [Pg.38]

The outcome of such calculations is shown graphically in Figure 6. Obviously this diagram is not only hypothetical but also schematical, and subject to qualifications and corrections. As it stands, it suggests that what we call the valine cell has a double-thickness wall and a double-thickness membrane, and is one third bigger than the exponential cell. On the other hand, the threonine cell is one third smaller than the exponential cell and it has a single-thickness membrane and a double-thickness wall. [Pg.150]

The L-threonine biosynthetic pathway consists of five enzymatic steps from L-aspartate. E. coli has three aspartate kinase isoenzymes, key enzymes which catalyze the first reaction of the L-threonine biosynthetic pathway. The aspartate kinase isoenzymes I, II, and III encoded by the thrA, metL, and lysC genes, respectively, are affected by feedback inhibition by L-threonine, L-methionine, and L-lysine, respectively. C. glutamicum has only one aspartate kinase encoded by the lysC gene, which is subjected to feedback inhibition by L-lysine and... [Pg.7]


See other pages where Subject threonine is mentioned: [Pg.343]    [Pg.797]    [Pg.162]    [Pg.200]    [Pg.253]    [Pg.411]    [Pg.767]    [Pg.208]    [Pg.162]    [Pg.401]    [Pg.411]    [Pg.255]    [Pg.611]    [Pg.269]    [Pg.251]    [Pg.88]    [Pg.125]    [Pg.127]    [Pg.191]    [Pg.270]    [Pg.430]    [Pg.109]    [Pg.36]    [Pg.87]    [Pg.116]    [Pg.545]    [Pg.362]    [Pg.692]    [Pg.872]    [Pg.118]    [Pg.220]    [Pg.210]    [Pg.291]    [Pg.131]    [Pg.197]    [Pg.160]    [Pg.152]   
See also in sourсe #XX -- [ Pg.1075 ]

See also in sourсe #XX -- [ Pg.1075 ]




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