Lysines polylysine

On the whole, curing procedures appear a promising way to obtain very stable polymer films. Thus, the structure of already mentioned polylysine has been revised as a block polymer involving either the a or e amino groups of lysine Vitamin Bj2 modified carbon electrodes were prepared by thermal curing of a mixture of a diamino functionalized derivative 5 and an epoxy prepolymer 6 of the araldite... 

Polymer grafting can be used to alter chemical and physical properties of a homopolymer. For example, Sawhney and Hubbell [18] grafted polyethyleneoxide to poly L-lysine to enhance biocompatibility of polylysine and improve the polylysine-alginate capsules. Stevenson and Sefton [19] modified alginate by grafting it with hydroxyalkyl methacrylate, again to improve the biocompatibility and to allow for polymerization by means of y-irradiation. Covalently modified (co)-polymers have not been evaluated in this study. 

The contents of the nucleic acid bases in the poly-L-lysine derivatives were determined by UV spectra of the polymers after hydrolysis The polymers were hydrolyzed in 6 N-hydrochloric acid at 105°C for 24 hr, into lysine dihydrochloride and the carboxyethyl derivatives of the nucleic acid bases. The quantitative calculation was made relative to the standard sample of the carboxyethyl derivative of the nucleic acid bases. The analytical data are listed in Table 1. It was found that the thymine and uracil derivatives was completely substituted to polylysine. Low value in case of adenine base in the polymer may be attributed to the unstability of the activated ester, Ade-PNP (2), and may also be explained in terms of the steric interaction among bulky pendant groups of the polymer. When the poly-L-lysine containing about 50 mol % adenine units was again treated with Ade-PNP, the adenine unit content in the polymer increased up to 74 mol %(,] ). 

Slight SH, Prabhakaram M, Shin DB, Feather MS and Ortwerth BJ (1992) The extent of N-(carboxymethyl)lysine formation in lens proteins and polylysine by the autoxidation products of ascorbic acid. Biochim Biophys Acta 1117, 199-206. 

Aleksina et al. investigating polymerization of methacrylic acid in the presence of poly-L-lysine found that the complex obtained by template polymerization has a 1 1 stoichiometry, while the same components obtained by separation of the complex and repeated mixing gave a complex in which the ratio of polylysine units to polyacid units is 2 3. The stable conformation of polylysine macromolecule in the complex obtained by template polymerization is the conformation of a-helix. 

Figure 4. Adsorption isotherms for polylysine (polymer containing 36 lysine molecules, data from Ref. 15) and dextran (molecular weight 77,600, data from Ref. 13) on human RBC surfaces (3)...

Figure 8. Transmission electron micrograph of aggregates of RBCs in poly lysine (19). Note the nonuniform intercellular spacing which contains strands of polylysine molecules (70,000X magnification).

Agglutination of RBCs by polycations (e.g. polylysines) involves electrostatic attraction between the positively charged lysine groups of the polylysine molecule and the negatively charged N-acetylneuraminic acid on the RBC surface. Reduction of RBC surface charge by neuraminidase treatment markedly decreases the effectiveness of RBC agglutination by polylysine. 

Chan, C.K. and Jans, D.A. (1999) Enhancement of polylysine-mediated transferrinfection by nuclear localization sequences poly lysine does not function as a nuclear localization sequence. Hum. Gene Ther., 10, 1695-1702. 

Figure 16.5 DTT releases pDNA from a disulfide-containing polylysine conjugate. pSV21uc plasmid (20 pg in 280 pi 10 mM Hepes buffer, pH 7.4) was mixed with either (A) disulfide-containing poly lysine (80pg) or (B) poly lysine (40 pg) in 120 pi 10 mM Hepes buffer, pH 7.4. After 30 minutes at 20 °C, polyplexes (50pl 2.5pg plasmid) were incubated at 37 °C for various times in the presence of 0.1 M DTT. Samples (20pl) were analyzed by 0.8% agarose gel electrophoresis. pSV21uc plasmid.

Figure 16.6 Polyfection mediated by a disulfide-containing poly lysine conjugate. (A) 293-T7 cells and (B) HepG2 cells were incubated for four hours at 37 °C with pCMVluc (5 pig) complexed with either disulfide-containing polylysine (20 pig) or polylysine (15 pig) in the presence of 10% FCS and 100 iM chloroquine. The luciferase activity was measured after 48 hours culture and expressed as the relative light units (RLU) per 106 cells.

Fig. 1.3 Polylysine dendrimer (according to Denkewalter et al.) the two peripheral lysine units are shown in green...

Synthesis of these dendrimers is performed by condensation of the amino acid lysine, whose amino functions have previously been protected with tert-bu-tyloxycarbonyl groups (Boc), onto an (activated) L-lysine p-nitrophenyl ester. The resulting coupling product (Fig. 4.11) is then deprotected with trifluoroacetic acid and thus activated for renewed reaction. Iteration of the assembly and activation step ultimately led to a polylysine dendrimer with 1024 terminal butyloxycarbonyl groups [21]. 

Fig. 4.10 Polylysine with a total of 80 boron atoms in the periphery (according to Qualmann et al.). For the sake of clarity a - peptide bonded - lysine building block in one of the dendri-mer branches is shown in green (PEG = polyethylene glycol)...

Kinetic studies of this reaction have shown that it obeys Michaelis-Menton kinetics as expressed by the Lineweaver-Burk plot, the Michaelis constant (KJ for this reaction at pH 7.0 and 37.5 °C being 2.86 x 10 4 M 24). Free lysine, Leuehs Poly-L-lysine, total hydrolyzates of thermal polylysine, and amino group-modified thermal polylysine are completely inactive. The activity of thermal polylysine depends on the degree of polymerization 24). 

Thermal polylysine also catalyzes the formation of a-ketoglutaric acid from glutamic acid with CuCl25). A reaction mixture of lysine-rich proteinoid (20 mg), 14C(U)-l-glutamate (0.1 mM), and CuCl (0.1 mM) in 6 ml of Britton-Robinson buffer (pH 7.0) is incubated at 37.5 °C for 2 hours. More than 40 % of the radioactivity used is recorded in a-ketoglutaric add by paperchromatography of the reaction mixture25 . Free lysine and Leuehs poly-L-lysine have no activity 2S). The reaction obeys Michaelis-Menten kinetics at optimum pH 7.0 25). 

The peroxidatic activity of hemoproteinoids, particularly, increase with their lysine content whereas the catalatic activity especially decreases in proteinoid with high phenylalanine content, hemo-polylysine (hematin is heated with Leuchs polylysine) has very weak peroxidatic activity 26). The relatively broad pH optimum of lysine-rich hemoproteinoid in the guaiacol test is in the neutral range 26). Nicotinamide adenosine dinucleotide-reduced form, NADH, is also oxidized by the hemoproteinoids 26). 

Lysine-rich proteinoids (thermal polylysine) inhibit the growth of roots and shoots of plants, Digitalis purpurea and Phacelia tanacetifolia 68). The growth inhibition by... 

Polylysine in neutral solution is evidently much more reactive than lysine (k = 2 x 107 at pH = 7-8) or lysyl-lysine (k< 5x 108 M-1 sec-1 at pH = 8). This enhancement in reactivity is probably related to the multi-... 

Tonegawa et al. (2004) created a cationic polylysine with a tetrapeptide end sequence (glycine-tyrosine-glycine-lysine), which is a motif common to the consensus sequences of mussel adhesive proteins. They then cross-linked this with the anionic polysaccharide, gellan, enzymatically. The polyionic complexation between the cationic peptide and the anionic polysaccharide formed a hybrid fiber at the aqueous solution interface that, when cross-linked, mimicked the byssus gel that marine mussels use to adhere to surfaces, despite the presence of water and salt. 

The disordering of polynucleotides by Cu(II) binding may be contrasted to the effects of Cu(II) on complexes of DNA with polylysine. Such complexes serve as models for the nucleoproteins found in the nuclei of eukaryotic cells. The nucleoproteins contain DNA bound to a variety of proteins, many of which contain a large amount of lysine. These proteins are believed to be involved in the regulation of genetic activity. 

The ADP-ribosylation of proteins is also feasible in the absence of the specific enzymes. Covalent adducts of polylysine, bovine serum albumin, lysine rich histone (FI) and DNase with ADP-ribose and ribose-5-phosphate have been prepared at pH 7.4 and 9.5 (52). The formation of a Schiff base was indicated by the incorporation of % into the adducts upon treatment with NaB- H.. 

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