Poly Lys l

Figure 2 Typical VCD and FUR Solution-Phase Spectra of Helix, Sheet, and Coil Conformations for Polypeptides (A) Alternate LKKL, (B) Alternate LK (high salt), and (C) Poly-L-Lys (neutral pH),230 a...

Fig. IS Poly(L-lys ine) containing 46 mol% spiropyran units (XVI) in HFP/ NEt3. Variation of ellipticity at 222 nm as a function oftriethylamine concentration forthe sample kept in the dark (continuous line) and after irradiation (dashed line).

Fig. 12 Substances used for complex formation and nanoparticles, (retinoic acid) All-trans retinoic acid, (PLA) poly(-L-arginine), (PLH) poly(-L-histidine), (PLL) poly(-L-ly-sine). As dispersing agent a tri-block copolymer was used. It consisted of ethylene oxide and propylene oxide (Poloxamer 188). Reprinted with permission from [142]. Copyright 2000 American Chemical Society...

The development of VCD as a peptide conformational probe proceeded in a manner similar to the one followed earlier by researchers in CD spectroscopy [38], Homo-polyamino acids, such as poly-L-Tyr or poly-L-Lys, for which the secondary structure is well known and can be varied as a function of solvent acidity, were studied via VCD, and distinct results for the established conformations were observed. These results are summarized in Figures 4 and 5. In poly-L-Tyr [41], for example, the a-heli-cal conformation exhibits a distinct, sharp and near-conservative positive / negative couplet in the amide I region. In the context of this discussion, "conservative couplet" implies equal positive and negative VCD intensities, and a description of positive / negative couplet always implies low to high wavenumber. The a-helical conformation is assumed by poly-L-Tyr in acidified DMSO solution (80% 20% by volume of DMSO... 

Figure 5. Infrared CD (top) and absorption Spectra (bottom) of a-helical (solid trace), "random coil (short dashes) and B-pleated poly-L-Lys (long dashes)...

Poly-(L-Lys)—NHC—CeH4—NHj Glass beads-Si-TrT Sephadex-(2-ethoxyethyl)-pU Poly(ethylene glycol)-0-MeOTr-T... 

Methods to stabilize, enhance cellular uptake, and alter the in vivo pharmacokinetic properties of poly rI poly rC were extensively studied. Polycationic substances such as DEAE-dextran (diethylyaminoethyl dextran), poly L-ly sine, and histones were shown to complex with poly rLpoly rC and other polynucleotides and alter all of these properties (7). Poly rLpoly rC, complexed with polylysine in the presence of carboxymethylcellulose, was studied in patients with cancer and found to be very toxic (12,13). 

Shen, W.C. and Ryser H.J. (1981) Poly(L-ly-sine) has different membrane transport and drug-carrier properties when complexed with heparin. Proc. Natl. Acad. Sci. USA 78, 7589-7593. 

The addition of organic solvents to aqueous peptide solutions can have significant effects on peptide conformation. For example, poly-L-Lys can be induced to change from an initially a-helical state to P-sheet by the addition of low concentrations of short-chain alcohols. The transformation can be reversed by the addition of higher concentrations (Shibata et al. 1992). 

Reaction with poly(-L-Lys)-coated polyacrylamide beads... 

Development of a simple technique has been reported for coating glass cover slips and plastic Petri dishes with various immune complexes.The supports were coated with poly(L-Lys), which was then treated with 2,4-dinitrobenzene sulphonate followed by glutaraldehyde-mediated reaction with the appropriate substance. 

S. VandeVondele, J. Voros, J.A. Hubbell, RGD-grafted poly-l-ly-sine-graft-(polyethylene glycol) copolymers block non-specific protein adsorption while promoting cell adhesion, Biotechnol. Bioeng. 82 (2003) 784-790. 

The most simple non-specific interactions are due to charge effects and are, therefore, characteristic of polycations. The inhibition of bacterial growth, which is easy to measure, provides very instructive quantitative data. The early study by Kat-chalski clearly demonstrated the importance of the macromolecular form. They compared the minimum concentrations of (L-lys) required to inhibit the growth of Escherichia coli. Values of 450,150,75 and 2,5 pg/ml for n = 2, n = 3, n = 4, and poly(L-lys), respectively, were found. On the other hand, a similar study with ionenes reflected the effect of charge separation. Concentrations of 128,16, 8, 32 and 4 gg/ml were found for 3,3-, 6,6-, 2,10-, 6,10-, and 6,16-ionene, respectively Macromolecular antimicrobial drugs promise many advantages over small molecules and were discussed in the excellent review by Samor Therefore, they have been the object of an intensive research 250,25i)... 

Methotrexate (MTX) is a widely used antitumor drug which selectively inhibits dihydrofolate reductase — an enzyme involved in the synthesis of DNA building blocks. Some tumor cells, however, become resistant to it due to the blocking of MTX transport inside the cell. Suprisingly, it was found > that attachment of MTX to some polymers may overcome this resistance by an increase of the drug transport inside the cell. Many polymers were tested and poly(L-lys) seems to be most... 

When the polymeric backbone is susceptible to hydrolysis, drug release may eventually result following degradation of the carrier. Ryser and Shen have shown that methotrexate (MTX) covalently bound to poly(L-lysine) (one molecule of drug per 27 lysyl residues) is able to impair the growth of a normally methotrexate — resistant Chinese hamster ovary cell line MTX-poly(L-Lys) is regarded as a lysosomotropic... 

Several years ago Seljelid et al. showed that poly(L-Lys) enhanced the uptake of H-labelled reovirus double-stranded RNA by macrophages and similarly it has been shown that poly(L-Lys), poly(D-Lys) and poly(L-omithine) markedly increase the rate of uptake of I-labelled albumin by Sarcoma S-180 cells grown in mono-layer In the latter experiments, Ryser found that the ability to stimulate uptake is clearly related to the molecular size of the polymer used. Recently, a horseradish peroxidase (HRP)-poly(L-Lys) conjugate was prepared and used to determine uptake by L-929 mouse fibroblasts grown as monolayers Measurements of the enzymatic... 

Among the various techniques for the immobilization of PEG on surfaces, - - graft copolymers of poly(L-ly sine) and poly(ethylene glycol) (PLL- -PEG) are particularly attractive. PLL- -PEG copolymers spontaneously adsorb from aqueous solutions as dense, monomolecular layers onto a rangeofnegatively charged surfaces such as various metal oxides and tissue-culture polystyrene, protecting them against nonspecific protein adsorption moreover,... 

Poly(L-Lys, L-Tyr)(l l) takes up an anti-parallel -structure at pH 9.2— I1.6, while block copolymers with the general structure (X-L-Ala-Gly)n in which X was L-ornithyl, L-l,4-diaminobutyryl or L-2,3-diaminopropanoyl, were shown by c.d. to be in random conformations. ... 

Harada, A., H. Togawa and K. Kataoka, 2001, Physicochemical properties and nuclease resistance of antisense- oligodeoxynucleotides entrapped in the core of polyion complex micelles composed of poly (ethylene glycol)-poly (L-Ly sine) block copolymers. Eur. J. Pharm. Sci. 13 35-42. 

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