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Journal of Nuclear Medicine : Official... Jul 1993Efforts to achieve rapid specific targeting of radioisotopes to disease processes using antibodies conjugated with avidin or streptavidin for pretargeting and...
Efforts to achieve rapid specific targeting of radioisotopes to disease processes using antibodies conjugated with avidin or streptavidin for pretargeting and radiobiotin derivatives for isotope delivery are attracting substantial interest. At present, these approaches appear to be limited by low delivery of radiotracer to the target. As an alternate radiobiotin tracer, biotinylated/iodinated polylysine (BIP) was prepared by conjugating poly-L-lysine (MW approximately 10,200) with biotin succinimide esters and the Bolton-Hunter reagent. This reagent was then radioiodinated with 125I via the lodogen method. BIP was characterized by radio-HPLC and its in vitro binding to streptavidin. The in vivo localization of BIP was evaluated in a rat model in which streptavidin agarose beads were physically localized to precapillary arterioles in the lungs. Biodistribution and blocking studies performed at 4 and 24 hr after BIP injection indicated specific binding and localization of the radiolabeled peptide to the lungs (lung-to-blood ratio approximately 8 at 4 hr postinjection). Comparative studies of BIP and 111In chelated to biotin showed BIP to have two-fold higher lung targeting and lower splenic and hepatic uptake than the 111In biotin derivative. Our study demonstrates: (1) the feasibility of using a small peptide as a biotin carrier for pretargeting (and for solubilizing organic tracers which may otherwise be difficult to administer in vivo) and (2) that BIP and BIP-like compounds may be suitable and simple alternatives to radiometal-labeled biotin for pretargeting and may offer improved targeting to prelocalized streptavidin.
Topics: Animals; Biotin; Chromatography, High Pressure Liquid; Female; Iodine Radioisotopes; Lung; Polylysine; Radioimmunodetection; Rats; Rats, Sprague-Dawley; Tissue Distribution
PubMed: 8315493
DOI: No ID Found -
Macromolecular Bioscience Sep 2014Fluorescent organic nanoparticles based on aggregation induced emission dyes are fabricated through a ring-opening reaction using polylysine as the linker. The...
Fluorescent organic nanoparticles based on aggregation induced emission dyes are fabricated through a ring-opening reaction using polylysine as the linker. The fluorescent organic nanoparticles obtained are characterized by a series of techniques including UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier Transform infrared spectroscopy, and transmission electron microscopy. A biocompatibility evaluation and the cell uptake behavior of the fluorescent organic nanoparticles are further investigated to evaluate their potential biomedical applications. It is demonstrated that these fluorescent organic nanoparticles can be obtained at room temperature in an air atmosphere without the need for catalyst or initiator. Furthermore, these crosslinked aggregation induced emission dye based fluorescent organic nanoparticles show uniform morphology, strong red fluorescence, high water dispersability, and excellent biocompatibility, making them promising candidates for various biomedical applications.
Topics: Cell Line; Fluorescent Dyes; Humans; Materials Testing; Microscopy, Fluorescence; Molecular Imaging; Nanoparticles; Polylysine
PubMed: 24854875
DOI: 10.1002/mabi.201400140 -
The Journal of Biological Chemistry Jun 2002An antiparallel actin dimer has been proposed to be an intermediate species during actin filament nucleation. We now show that latrunculin A, a marine natural product...
An antiparallel actin dimer has been proposed to be an intermediate species during actin filament nucleation. We now show that latrunculin A, a marine natural product that inhibits actin polymerization, arrests polylysine-induced nucleation at the level of an antiparallel dimer, resulting in its accumulation. These dimers, when composed of pyrene-labeled actin subunits, give rise to a fluorescent excimer, permitting detection during polymerization in vitro. We report the crystallographic structure of the polylysine-actin-latrunculin A complex at 3.5-A resolution. The non-crystallographic contact is consistent with a dimeric structure and confirms the antiparallel orientation of its subunits. The crystallographic contacts reveal that the mobile DNase I binding loop of one subunit of a symmetry-related antiparallel actin dimer is partially stabilized in the interface between the two subunits of a second antiparallel dimer. These results provide a potential explanation for the paradoxical nucleation of actin filaments that have exclusively parallel subunits by a dimer containing antiparallel subunits.
Topics: Actins; Animals; Crystallography, X-Ray; Dimerization; Models, Molecular; Polylysine; Protein Conformation; Rabbits
PubMed: 11932258
DOI: 10.1074/jbc.M201371200 -
Archives of Biochemistry and Biophysics Sep 1989The addition of polylysine to a heavy fraction of sarcoplasmic reticulum (SR) vesicles produces a rapid Ca2+ release with no appreciable lag period. The polylysine...
The addition of polylysine to a heavy fraction of sarcoplasmic reticulum (SR) vesicles produces a rapid Ca2+ release with no appreciable lag period. The polylysine concentration for half-maximal activation (C1/2) is approximately 0.99 micrograms/ml, or 0.3 microM, the lowest C 1/2 for Ca2+ release-inducing reagents reported in the literature. The time course and the [Ca2+] dependence of polylysine-induced release are similar to those of caffeine-induced Ca2+ release. At higher concentrations of polylysine (e.g., 10 micrograms/ml), however, little or no Ca2+ release occurs. Upon photolysis of SR vesicles with the photocrosslinkable radiolabeled polylysine derivative, [3H]succinimidyl azido benzoate polylysine, 0.28 and 0.52-1.2 mol polylysine were bound to 1 mol of the 400-kDa foot protein at activating (3 micrograms/ml) and inhibitory (10 micrograms/ml) concentrations of polylysine, respectively. On the other hand, the amounts of polylysine bound to the other SR proteins (mol/mol) were negligible (e.g., less than or equal to 0.0127 mol polylysine/mol calsequestrin). This suggests that the binding of polylysine to the foot protein is responsible not only for the induction of release but also for inactivation. These results provide direct evidence that the receptor for the chemical trigger of Ca2+ release is localized within the foot protein. Ruthenium red, which inhibits polylysine-induced Ca2+ release, does not inhibit polylysine binding to the foot protein, suggesting that the polylysine binding domain of the foot protein is different from the channel domain.
Topics: Affinity Labels; Animals; Autoradiography; Calcium; Calcium-Binding Proteins; Electrophoresis, Polyacrylamide Gel; Polylysine; Rabbits; Ruthenium Red; Sarcoplasmic Reticulum
PubMed: 2476071
DOI: 10.1016/0003-9861(89)90515-8 -
Medical Science Monitor : International... Sep 2017BACKGROUND The antimicrobial mechanisms of ε-polylysine (EPL) against Pseudomonas aeruginosa and Aspergillus fumigatus biofilm were investigated. MATERIAL AND METHODS...
BACKGROUND The antimicrobial mechanisms of ε-polylysine (EPL) against Pseudomonas aeruginosa and Aspergillus fumigatus biofilm were investigated. MATERIAL AND METHODS We assessed the changes in electric conductivity of broth and total sugar concentration, as well as changes in phosphorous metabolism and protein expression, of the 2 organisms before and after treatment with EPL. RESULTS The experimental results showed that EPL has antimicrobial activity against Pseudomonas aeruginosa and Aspergillus fumigatus, but the activity was much stronger for the former. After treatment with EPL, the electric conductivity and total sugar concentration of microbial broth increased, suggesting that EPL damages the cell membrane structure, which increases permeability of the cell membrane and release of cell components. CONCLUSIONS The consumption of phosphorous decreased in the EPL-treated organisms, which seriously affected the synthesis of important cell components such as nucleic acid and phospholipid, as well as energy metabolism.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Aspergillus fumigatus; Biofilms; Microbial Sensitivity Tests; Polylysine; Pseudomonas aeruginosa
PubMed: 28863128
DOI: 10.12659/msm.903145 -
International Journal of Biological... Jan 2024The development and application of antibacterial film were highly anticipated to prevent food spoilage caused by bacteria. In this investigation, antibacterial and...
The development and application of antibacterial film were highly anticipated to prevent food spoilage caused by bacteria. In this investigation, antibacterial and antioxidant functionalized gelatin-based film was formed with the incorporation of oregano essential emulsion Pickering emulsion (OPE). ε-Polylysine-Carboxymethyl Chitosan nanoparticles (CMCS-ε-PL) composed of different mass ratios of CMCS and ε-PL were orchestrated by electrostatic forces and hydrogen bonding, which effectively acted as a stabilizer for OPE. The design of different mass ratios of CMCS and ε-PL in CMCS-ε-PL has a deep effect on the structure and functional properties of OPE and film. It successfully improved the encapsulation efficiency of OPE from 49.52 % to 79.83 %. With the observation of AFM images, the augmentation of surface roughness consequent to OPE incorporation can be relieved by the increased contention of ε-PL in CMCS-ε-PL. Meanwhile, the mechanical properties, barrier properties, anti-oxidation, and antibacterial properties of the films were improved with the incorporation of the above OPE. In particular, a synergistic antibacterial activity between ε-PL and OEO in the film was demonstrated in this study and the mechanism of enhanced antibacterial activity was elucidated by examining the integrity of bacteria cell membrane. The film unequivocally demonstrated its ability to appreciably prolong the shelf life of both beef and strawberries with excellent antioxidant and antibacterial properties.
Topics: Animals; Cattle; Antioxidants; Polylysine; Chitosan; Emulsions; Gelatin; Anti-Bacterial Agents; Nanoparticles
PubMed: 37984581
DOI: 10.1016/j.ijbiomac.2023.128043 -
International Journal of Biological... Dec 2019Of late, the demand for food-packaging materials, in particular, multifunction packaging materials that are biodegradable; antibacterial; have good mechanical and...
Of late, the demand for food-packaging materials, in particular, multifunction packaging materials that are biodegradable; antibacterial; have good mechanical and barrier properties; and are edible and transparent, has increased considerably. In this study, we prepared chitosan (CS)/ε-polylysine (PL) biofilms with different CS-to-PL ratios. We studied the preparation, mechanical properties, microstructures, thermal stability, transparency, water-vapor permeability, oil permeability, and antibacterial properties of the composite CS/PL biofilms. The results demonstrate that CS/PL biofilms are mechanically strong, have good thermal stability, high transparency, low water-vapor and oil permeability, and extensive antibacterial properties that act against Escherichia coli, Bacillus subtilis, and yeast. Therefore, we therefore conclude that CS/PL biofilms are promising food-packaging materials.
Topics: Anti-Infective Agents; Bacillus subtilis; Biofilms; Chitosan; Escherichia coli; Polylysine; Yeasts
PubMed: 31499113
DOI: 10.1016/j.ijbiomac.2019.09.035 -
Amino Acids Mar 2013Differential anti-prion activity of polylysine enantiomers was studied. Based on our recent discovery that poly-L-lysine (PLK) is a potent anti-prion agent, we...
Differential anti-prion activity of polylysine enantiomers was studied. Based on our recent discovery that poly-L-lysine (PLK) is a potent anti-prion agent, we investigated suppression of prions in cultured cells using poly-D-lysine (PDK). The results showed that PDK was more efficacious than PLK to inhibit prions. Protein misfolding cyclic amplification assay demonstrated improved efficacy of PDK in inhibiting plasminogen-mediated prion propagation, corresponding to the enantio-preference of PDK observed in cultured cells. Furthermore, our study demonstrated that polylysines formed a complex with plasminogen. These results propose to hypothesize a plausible mechanism that elicits prion inhibition by polylysine enantiomers.
Topics: Cell Line; Down-Regulation; Humans; Kinetics; Plasminogen; Polylysine; Prions; Protein Folding; Stereoisomerism
PubMed: 23179088
DOI: 10.1007/s00726-012-1430-8 -
International Journal of Molecular... Oct 2021In this study, ε-polylysine and calcium phosphate precipitation (CPP) methods were employed to induce antibacterial effects and dentin tubule occlusion. Antibacterial...
In this study, ε-polylysine and calcium phosphate precipitation (CPP) methods were employed to induce antibacterial effects and dentin tubule occlusion. Antibacterial effects of ε-polylysine were evaluated with broth dilution assay against CPP solution from MCPM, DCPD, and TTCP was prepared. Four concentrations of ε-polylysine(ε-PL) solutions (0.125%, 0.25%, 0.5%, 1%) were prepared. Dentin discs were prepared from recently extracted human third molars. Dentin discs were incubated with (ATCC 33277) bacterial suspension (ca. 10 bacteria) containing Brain Heart Infusion medium supplemented with 0.1 g/mL Vitamin K, 0.5 mg/mL hemin, 0.4 g/mL L-cysteine in anaerobic jars (37 °C) for 7 days to allow for biofilm formation. -infected dentin specimens were randomly divided into four groups: CPP + 0.125% ε-PL, CPP + 0.25% ε-PL, CPP + 0.5% ε-PL, CPP + 1% ε-PL. On each dentin specimen, CPP solution was applied followed by polylysine solution with microbrush and immersed in artificial saliva. Precipitate formation, antibacterial effects, and occlusion of dentinal tubules were characterized in vitro over up to 72 h using scanning electron microscopy. ε-PL showed 34.97% to 61.19% growth inhibition levels against () after 24 h of incubation. On -infected dentin specimens, DCPD + 0.25% ε-PL, and DCPD + 0.5% ε-PL groups showed complete bacterial inhibition and 78.6% and 98.1% dentin tubule occlusion, respectively ( < 0.001). The longitudinal analysis on fractured dentin samples in DCPD and TTCP groups revealed deeply penetrated hydroxyapatite-like crystal formations in dentinal tubules after 72 h of incubation in artificial saliva.
Topics: Anti-Bacterial Agents; Calcium Phosphates; Dentin; Dentin Sensitivity; Humans; Microbial Sensitivity Tests; Polylysine; Spectrum Analysis; Surface Properties
PubMed: 34639022
DOI: 10.3390/ijms221910681 -
Journal of Lipid Research Dec 2003Oral administration of epsilon-polylysine to rats reduced the peak plasma triacylglycerol concentration. In vitro, epsilon-polylysine and polylysine strongly inhibited...
Oral administration of epsilon-polylysine to rats reduced the peak plasma triacylglycerol concentration. In vitro, epsilon-polylysine and polylysine strongly inhibited the hydrolysis, by either pancreatic lipase or carboxylester lipase, of trioleoylglycerol (TO) emulsified with phosphatidylcholine (PC) and taurocholate. The epsilon-polylysine concentration required for complete inhibition of pancreatic lipase, 10 microg/ml, is 1,000 times lower than that of BSA required for the same effect. Inhibition requires the presence of bile salt and, unlike inhibition of lipase by other proteins, is not reversed by supramicellar concentrations of bile salt. Inhibition increases with the degree of polylysine polymerization, is independent of lipase concentration, is independent of pH between 5.0 and 9.5, and is accompanied by an inhibition of lipase binding to TO-PC emulsion particles. However, epsilon-polylysine did not inhibit the hydrolysis by pancreatic lipase of TO emulsions prepared using anionic surfactants, TO hydrolysis catalyzed by lingual lipase, or the hydrolysis of a water-soluble substrate. In the presence of taurocholate, epsilon-polylysine becomes surface active and adsorbs to TO-PC monomolecular films. These results are consistent with epsilon-polylysine and taurocholate forming a surface-active complex that binds to emulsion particles, thereby retarding lipase adsorption and triacylglycerol hydrolysis both in vivo and in vitro.
Topics: Administration, Oral; Adsorption; Animals; Bile Acids and Salts; Buffers; Dose-Response Relationship, Drug; Emulsions; Enzyme Inhibitors; Hydrolysis; Kinetics; Lipase; Male; Pancreas; Polylysine; Rats; Rats, Wistar; Triglycerides
PubMed: 12951365
DOI: 10.1194/jlr.M300151-JLR200