Lysin monomer

This section reports on the physicochemical characteristics of water-soluble complexes formed between PEO-PLL block copolymers and retinoic acid. Two block copolymers were used. The lengths of the PEO blocks in both are identical, the molecular weight was 5000 g/mol (Mw/Mn=l.l). This corresponds to a degree of polymerization of 114. The length of the PLL block varies PEO-PLL18 has 18 L-lysine monomer units and PEO-PLL30 has 30. A sketch of the molecular structures is given in Fig. 17. 

Figure 11. The crystal structure of the red abalone lysin monomer. The a-carbon trace shows the five a-helices numbered a-1 to a-5 and the two basic tracks of Arg and Lys residues. The left basic track contains nine residues and the right track 14 residues (Arg and Lys are not visible in the crystal structure). The two termini are labeled N and C. The N-terminal segment of residues 1 to 12 extends away from the helical bundle and the hypervariable N- and C- termini are in proximity (from Shaw et al., 1993). In the Arg and Lys side chains, carbon atoms are white and nitrogen atoms dark gray.

Figure 12. Placement of the 11 residues of the hydrophobic patch on the surface of the lysin monomer. The patch represents 10% of lysin s surface area (Shaw et al., 1993). The single letter code for amino acids is used. In the hydrophobic patch side chains, carbon atoms are black and nitrogen, oxygen,and sulfur atoms are dark gray, gray, and light gray, respectively.

Figure 1. A schematic illustration of PLL-g-PEG/FITC adsorbed onto an oxide substrate surface in an aqueous environment (pH 7). Note that the ratio between the lysine monomers grafted to PEG side chains and those available for interaction with the oxide surface in this figure is 1 3 (lysine-mer/PEG side chain = 4), which is slightly di-erent from that of the PLL-g-PEG employed throughout the experiments, 1 2.4 (g = 3.4). The FITC label is also not necessarily at the end of the PLL chain in reality.

Fig. 4 Molecular weight (a), lysine monomer density (niyg) (b), dextran ( dex) or PEG (wpeg) chain density (c), and density of the monomer units of...

Once the adsorbed polymer mass is known, it is straightforward to deduce the lysine (monomer) and the PEG chain surface densities expressed as [molecules per... 

Figure 4. Adsorption data for PLL-g-PEG polymers with a 20 kDa PLL backbone, 1,2, or 5 kDa PEG side chains, and NMR-derived grafting ratios g (=Lys-mers per PEG side chain) ranging from 2 to 23, plotted as a function of the inverse of the grating ratiog, that is, PEG/Lys, in the bulk pol3uner (a) total polymer mass, m i, monitored by OWLS (b) polymer surface density expressed as the number of lysine monomers per square nanometer, ULys (c) PEG chain surface density expressed as the number of PEG chains per square nanometer, upeg-...

The notation PLL(x)-g[y]-dex(2) for the copolymers was used to represent the molar mass of PLL in kilodaltons (x) (including the counterions, Br-, as precursor), the molar mass of dextran in kilodaltons (j), and the grafting ratio g[y] (defined as the number of lysine monomers/dextran side chain). 

Figure 4. Lysine monomer density (niys) and dmttranchaindaisily (ridex) as a function of grafting ratio (g) forthe PLL(13)-g-dmt(5.9) andPLL(6)-g-dex(5.9) copolymers.

Daruvala ST. The eificacy of polylysine, lysine monomer uid polyethylene glycol as excipients for the controlled release of nerve growth factor from freeze dry silk scaffolds. Department of Biology Tufts University 2013. 

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