Structure 2-amino-3-carboxy

Figure 12. Stereoviews of the solution NMR structure ofRo 09-0198 (coordinates courtesy of H. Kessler (121)) that show (A) van der Wools surfaces of the Phe and Val side chains and (B) van der Wools surfaces of the charged amino, carboxy, and guanido groups.

A representative structure of this type of material is shown in Fig. 5. Cavedon line (Table 1) includes amino, carboxy, oleophilic, meth-acryloxy, and mercapto functionality. 

For covalently bonded immobilizates functionalized polymer structures have to be designed for the preparation of functionalized polymeric films on electrodes ( functionalized polymer-covered electrodes )- Some 3-functionalized thiophene derivatives have been prepared, bearing e.g. carboxy, activated ester, hydroxy, amino groups, ready for reaction with bioorganic compounds via amino, carboxy or hydroxy groups of the biomolecules as well known in peptide chemistry. 

Pterin, 4-amino — see Folic acid, 4-amino-4-deoxy-Pterin, 6-amino-structure, 3, 276 Pterin, 7-amino-structure, 3, 276 Pterin, 6-arylthio-reactivity, 3, 299 Pterin, 6-(l-carboxyethoxy)-synthesis, 3, 309 Pterin, 6-carboxy-7-hydroxy-properties, 3, 277 Pterin, 7-carboxy-6-hydroxy-properties, 3, 277 Pterin, 6-chloro-nucleophilic substitution, 3, 292 synthesis, 3, 290... 

In almost every one of the more than 100 different known a/p structures 1 of this class the active site is at the carboxy edge of the p sheet. Functional residues are provided by the loop regions that connect the carboxy end of the strands with the amino end of the a helices. In this one respect a fun-I damental similarity therefore exists between the a/p-barrel structures and the I open a/p-sheet structures. 

The a/p-barrel structure is one of the largest and most regular of all domain structures, comprising about 250 amino acids. It has so far been found in more than 20 different proteins, with completely different amino acid sequences and different functions. They are all enzymes that are modeled on this common scaffold of eight parallel p strands surrounded by eight a helices. They all have their active sites in very similar positions, at the bottom of a funnel-shaped pocket created by the loops that connect the carboxy end of the p strands with the amino end of the a helices. The specific enzymatic activity is, in each case, determined by the lengths and amino acid sequences of these loop regions which do not contribute to the stability of the fold. 

Five of the six loop regions (G1-G5 in Figure 13.4) that are present at the carboxy end of the p sheet in the Ras structure participate in the GTP binding site. Three of these loops, G1 (residues 10-17), G3 (57-60), and G4 (116-119), contain regions of amino acid sequence conserved among small GTP-binding proteins and the Ga subunits of trimerlc G proteins. 

Na+/H+ Exchangers. Figure 1 Prototypical structure and transmembrane disposition of NHE. The amino (N) and carboxy termini of the molecule are indicated. 

The P2X receptor subunits are unusual in having only two transmembrane domains with both the amino terminal and carboxy terminal located intracellularly. The ion channel is proposed by analogy with the structure of some potassium channels to be formed by a short loop which enters the membrane from the extracellular side (North and Surprenant 2000). 

When one inspects the multiple channel protein sequences that have been derived, one readily recognizes that they have related primary sequences. This suggests that they have similar three-dimensional structures. The primary sequences can be subdivided into an amino-terminal, a core and a carboxy-terminal domain (see Fig. 5). Each domain seems to contribute separately to the structure and function of a given channel [49]. Following this hypothesis, it has been possible to carry out domain swapping experiments between Sh and RCK proteins [49] as well as between... 

L-piperidine-2-carboxylic acid is a non-proteinogenic amino acid that is a metabolite of lysine. The zinc complexes of DL-piperidine-2-carboxylic acid, DL-piperidine-3-carboxylic acid, and piperidine-4-carboxylic acid have been studied. The X-ray crystal structures have been determined for the latter two. [ZnCl2(DL-piperidine 3-carboxylate)2] (42) is monomeric with a tetrahedral metal center and monodentate carboxylates. [Zn2Cl4(piperidine-4-carboxylate)2] (43) contains two bridging carboxylates in a dimeric structure. IR studies suggest that the DL-piperidine-2-carboxy-lato zinc has monodentate carboxylate ligands coordinating.392... 

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