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Analytical Biochemistry Nov 1984A simple and sensitive method for the determination of polylysine in solution is described. Polylysine is quantitatively precipitated with trypan blue. The absorbance of...
A simple and sensitive method for the determination of polylysine in solution is described. Polylysine is quantitatively precipitated with trypan blue. The absorbance of unbound dye in the supernatant is inversely proportional to the concentration of this polyamino acid. The precipitation is identical for all sizes of polylysine of molecular weight 13,000 or higher, and is prevented by the addition of either polyanions or serum. The measurable range of polylysine hydrobromide is between 1 and 10 micrograms/ml, which is about 10-fold lower than that by the published methyl orange precipitation method.
Topics: Azo Compounds; Chemical Precipitation; Colorimetry; Microchemistry; Peptides; Polylysine; Spectrophotometry; Trypan Blue
PubMed: 6549372
DOI: 10.1016/0003-2697(84)90500-1 -
Analytical Sciences : the International... 2014This article describes new analytical methods for studying biopolymer ε-poly-L-lysine (εPL). The produced amount of εPL in culture broth can be determined based on... (Review)
Review
Analytical methods for the detection and purification of ε-poly-L-lysine for studying biopolymer synthetases, and bioelectroanalysis methods for its functional evaluation.
This article describes new analytical methods for studying biopolymer ε-poly-L-lysine (εPL). The produced amount of εPL in culture broth can be determined based on the precipitation of polycationic εPL with a colored heteropolymolybdate anion and the color change of the supernatant. The product can be separated and purified by precipitation with the tetraphenylborate anion and reprecipitation in the form of the hydrochloride salt. These methods have been applied advantageously to the screening of εPL-synthetase. Also, pyrophosphate can be determined colorimetrically based on the formation of 18-molybdopyrophosphate species. The pyrophosphate determination has been successfully applied to the assay of adenylation enzyme, which plays important roles in the biosynthetic mechanism. Under certain conditions, εPL associates with a redox enzyme, glucose oxidase. The effect of the adduction on the stability and reaction rate of the enzyme can be evaluated by measuring the bioelectrocatalytic current, which is related to the enzyme activity. Electrochemical studies showed new applications of εPL as an enzyme stabilizer and a reaction enhancer.
Topics: Biopolymers; Biosensing Techniques; Electrochemical Techniques; Glucose Oxidase; Ligases; Polylysine
PubMed: 24420240
DOI: 10.2116/analsci.30.17 -
Mini Reviews in Medicinal Chemistry Feb 2004This review article deals with the synthesis, physiochemical properties, and potential biomedical applications of two homo-poly amino acids. Poly-alpha-glutamic acid... (Review)
Review
This review article deals with the synthesis, physiochemical properties, and potential biomedical applications of two homo-poly amino acids. Poly-alpha-glutamic acid (alpha-PGA) and poly-alpha-lysine (alpha-PL) were synthesized by chemical synthesis. poly-gamma-glutamic acid (gamma-PGA) and poly-epsilon-lysine (epsilon-PL) were naturally occurring bio-materials that were produced by microbial fermentation. Poly(glutamic acid) (PGA) and poly(lysine) (PL) are water soluble, biodegradable, edible and nontoxic toward humans and the environment. As a result, they are suitable for various applications and have recently attracted considerable interest of the chemical industry. The distinguished features of PGA and PL also make them promising candidates for biomedical applications. The applications of PGA and PL in the areas of biomedical materials, drug delivery carriers and biological adhesives have been studied extensively and will be discussed in this review.
Topics: Adhesiveness; Animals; Bacteria; Chemical Phenomena; Chemistry, Physical; Drug Carriers; Fermentation; Humans; Polyglutamic Acid; Polylysine
PubMed: 14965290
DOI: 10.2174/1389557043487420 -
The Journal of Biological Chemistry Feb 1999Complexes composed of peptide ligand for the serpin enzyme complex receptor covalently coupled to poly-L-lysine condensed by charge interaction with plasmid DNA direct...
Complexes composed of peptide ligand for the serpin enzyme complex receptor covalently coupled to poly-L-lysine condensed by charge interaction with plasmid DNA direct gene transfer into receptor bearing cells. We compared intensity and duration of reporter gene expression in vitro and in vivo from serpin-enzyme receptor-directed gene transfer complexes prepared with poly-L-lysine of different chain lengths. When substituted with linker and ligand to comparable extents, DNA complexes containing short chain poly-L-lysine were larger and gave higher peak expression but significantly shorter duration of expression than those containing long chain poly-L-lysine. Both peak expression and duration of expression exceeded that observed with Lipofectin. Neither naked DNA nor DNA complexed with unsubstituted polylysine was effective in gene transfer. For in vivo experiments, complexes containing optimal ligand and degree of substitution (based on in vitro data, peptide C105Y, 11 ligands/plasmid DNA molecule) were prepared with either short chain or long chain polylysine and a beta-galactosidase expression plasmid. Following injection into the tail veins of mice, longer chain complexes gave significantly higher expression of reporter gene in lung and spleen that lasted for a significantly longer period of time than the shorter chain complexes. The short chain poly-L-lysine-DNA complexes were larger in diameter, as assessed by electron microscopy or atomic force microscopy, and gave less protection against DNase digestion in vitro than longer chain complexes. Thus, for gene transfer complexes directed at the serpin enzyme complex receptor, longer chain poly-L-lysine gave a much longer duration of expression both in vitro and in vivo. We speculate that this may be due to protection against degradation afforded the plasmid DNA by the tighter compaction produced by long chain poly-L-lysine.
Topics: Amino Acid Sequence; Animals; Cell Line; Gene Expression Regulation; Gene Transfer Techniques; Genes, Reporter; Ligands; Magnetic Resonance Spectroscopy; Mice; Microscopy, Atomic Force; Microscopy, Electron; Molecular Sequence Data; Polylysine
PubMed: 9988733
DOI: 10.1074/jbc.274.8.4908 -
The Journal of Pharmacy and Pharmacology Feb 1993Microcapsules, prepared with alginate and polylysine, were injected intraperitoneally into mice and the number of peritoneal leucocytes as well as the cells sticking to...
Microcapsules, prepared with alginate and polylysine, were injected intraperitoneally into mice and the number of peritoneal leucocytes as well as the cells sticking to the capsule wall were counted after 4-28 days. A significant increase in host reaction was observed when the microcapsules contained an outer layer of polylysine as compared with calcium alginate beads without polylysine or microcapsules coated with an outer layer of alginate. The alginate sources influenced the host reaction significantly. After an intraperitoneal residence of 4 days, the microcapsules were mainly surrounded by macrophages. After 28 days, several cell layers surrounded the microcapsules; macrophages, multinucleate giant cells, fibroblasts and mesothelial cells.
Topics: Alginates; Animals; Capsules; Injections, Intraperitoneal; Leukocyte Count; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Microscopy, Electron; Molecular Weight; Particle Size; Polylysine
PubMed: 8095525
DOI: 10.1111/j.2042-7158.1993.tb03694.x -
Journal of Agricultural and Food... Jan 2010epsilon-Polylysine (EPL) has been used in the food industry as an antimicrobial additive and also a dietary agent. To generate amphiphilic molecules from EPL,...
epsilon-Polylysine (EPL) has been used in the food industry as an antimicrobial additive and also a dietary agent. To generate amphiphilic molecules from EPL, hydrophobically modified epsilon-polylysine graft copolymers, which were denoted as OSA-g-EPLs, were synthesized by reacting EPL with octenyl succinic anhydride (OSA). The success of synthesis was confirmed by (1)H NMR and FT-IR spectroscopy. It was found that OSA-g-EPLs had glass transition temperatures lower than EPL. Furthermore, they were able to form polymer micelles in water and to lower the surface tension of water, confirming their amphiphilic properties. The antimicrobial activities of OSA-g-EPLs were also examined, and the minimum inhibitory concentrations of OSA-g-EPLs against Escherichia coli O157:H7 remained the same as that of EPL. Therefore, OSA-g-EPLs have the potential of becoming bifunctional molecules, which can be used either as surfactants or emulsifiers in the encapsulation of nutraceuticals or drugs or as antimicrobial agents.
Topics: Anti-Infective Agents; Emulsifying Agents; Escherichia coli O157; Polylysine; Succinic Anhydrides; Surface Properties
PubMed: 20020765
DOI: 10.1021/jf903300m -
Cold Spring Harbor Protocols Apr 2012The terplex system for delivering DNA to targeted cells comprises three components-stearyl polylysine (PLL), low-density lipoprotein (LDL), and DNA. This article...
The terplex system for delivering DNA to targeted cells comprises three components-stearyl polylysine (PLL), low-density lipoprotein (LDL), and DNA. This article describes a method for optimizing the relative amounts of these components and determining the transfection parameters for a given cell line.
Topics: Animals; Cell Line; DNA; Hydrophobic and Hydrophilic Interactions; Lipoproteins, LDL; Mice; Plasmids; Polylysine; Transfection
PubMed: 22474667
DOI: 10.1101/pdb.prot068627 -
Biomacromolecules Oct 2012Lysine-based polycations are widely used as nonviral carriers for gene delivery. This manuscript reports the results of a comparative study on the in vitro cytotoxicity... (Comparative Study)
Comparative Study
Lysine-based polycations are widely used as nonviral carriers for gene delivery. This manuscript reports the results of a comparative study on the in vitro cytotoxicity of a library of three structural polylysine variants, namely, linear polylysine (LPL), dendritic polylysine (DPL), and hyperbranched polylysine (HBPL). The aim of this study was to identify possible effects of polymer molecular weight and architecture on both immediate and delayed cytotoxicity and also to provide a mechanistic understanding for possible differences. Acute cytotoxicities were evaluated using cell viability assays with CHO DG44 cells. At comparable molecular weights, the EC(50) values for the LPL analogues were ∼5-250 times higher as compared to the DPL and HBPL samples. For low molecular weight polycations, osmotic shock was found to be an important contributor to immediate cell death, whereas for the higher molecular weight analogues, direct cell membrane disruption was identified to play a role. Delayed cytotoxicity (≥3 h) was assessed by identifying several of the hallmark events that characterize apoptosis, including phosphatidyl serine translocation, mitochondrial membrane depolarization, cytoplasmic cytochrome C release, and caspase 3 activation. At comparable molecular weights, apoptosis was found to be more pronounced for DPL and HBPL as compared to LPL. This difference was ascribed to the fact that LPL is completely enzymatically degradable, in contrast to DPL and HBPL, which also contain ε-peptidic bonds and are only partially degradable. Because their toxicity profiles are similar, HBPL is an interesting (i.e., synthetically easily accessible and inexpensive) alternative to DPL for the nonviral delivery of DNA.
Topics: Animals; Apoptosis; CHO Cells; Cell Membrane; Cell Membrane Permeability; Cell Survival; Cells, Cultured; Cricetinae; Dendrimers; Dose-Response Relationship, Drug; Molecular Structure; Molecular Weight; Polylysine; Structure-Activity Relationship
PubMed: 22931162
DOI: 10.1021/bm300930j -
Colloids and Surfaces. B, Biointerfaces Aug 2017Thin films mimicking the structure and composition of the extra-cellular matrix (ECM) are potentially attractive as biomaterials for cell contacting applications....
Thin films mimicking the structure and composition of the extra-cellular matrix (ECM) are potentially attractive as biomaterials for cell contacting applications. Layer-by-layer (LbL) assembly of a biological polycation, poly(l-lysine) (PLL), and a common ECM protein, fibronectin (Fn), was employed here to construct nanoscale, ECM mimicking films. Incremental film thickness and interfacial charge magnitude are observed to diminish with layer number, resulting in sub-linear film growth scaling and saturation after about 10 layers. Infrared spectroscopy and electron microscopy together reveal the formation of Fn containing aggregates, whose presence correlates with diminished charge reversal and suppressed LbL assembly. PLL-Fn films induce a significantly greater murine MC3T3-E1 pre-osteoblastic cell proliferation, while maintaining a much higher proportion of Fn in the molecular (as opposed to fibrillar) state, compared to a Fn monolayer, suggesting the enhanced Fn content of these ECM-mimicking films to significantly, and positively, affect cell behavior.
Topics: 3T3 Cells; Animals; Cell Adhesion; Cell Proliferation; Fibronectins; Mice; Polylysine
PubMed: 28544963
DOI: 10.1016/j.colsurfb.2017.05.023 -
Journal of Tissue Engineering and... Mar 2022After an injury, soft tissue structures in the body undergo a natural healing process through specific phases of healing. Adhesions occur as abnormal attachments between...
After an injury, soft tissue structures in the body undergo a natural healing process through specific phases of healing. Adhesions occur as abnormal attachments between tissues and organs through the formation of blood vessels and/or fibrinous adhesions during the regenerative repair process. In this study, we developed an adhesion-preventing membrane with an improved physical protection function by modifying the surface of chondrocyte-derived extracellular matrices (CECM) with anti-adhesion function. We attempted to change the negative charge of the CECM surface to neutral using poly-L-lysine (PLL) and investigated whether it blocked fibroblast adhesion to it and showed an improved anti-adhesion effect in animal models of tissue adhesion. The surface of the membrane was modified with PLL coating (PLL 10), which neutralized the surface charge. We confirmed that the surface characteristics except for the potential difference were maintained after the modification and tested cell attachment in vitro. Adhesion inhibition was identified in a peritoneal adhesion animal model at 1 week and in a subcutaneous adhesion model for 4 weeks. Neutralized CECM (N-CECM) suppressed fibroblast and endothelial cell adhesion in vitro and inhibited abdominal adhesions in vivo. The CECM appeared to actively inhibit the infiltration of endothelial cells into the injured site, thereby suppressing adhesion formation, which differed from conventional adhesion barriers in the mode of action. Furthermore, the N-CECM remained intact without degradation for more than 4 weeks in vivo and exerted anti-adhesion effects for a long time. This study demonstrated that PLL10 surface modification rendered a neutral charge to the polymer on the extracellular matrix surface, thereby inhibiting cell and tissue adhesion. Furthermore, this study suggests a means to modify extracellular matrix surfaces to meet the specific requirements of the target tissue in preventing post-surgical adhesions.
Topics: Adhesives; Animals; Chondrocytes; Endothelial Cells; Extracellular Matrix; Polylysine; Tissue Adhesions
PubMed: 34788485
DOI: 10.1002/term.3263