• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.801-807
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• 1994

Lactose substituted styrene monomer, N-(p-vinylbenzyl)-D-lactonamide(VLA) was prepared by coupling the lactose lactone with p-vinylbenzylamine. The carboxyl group of biotin was activated with N-hydroxysuccinimide in the presence of N, N'-dicyclohexylcarbodiimide. Subsquently, biotin substituted styrene monomer, N-(p-vinylbenzyl)-biotinamide(VBA) was prepared by amidation of the activated biotin with p-vinylbenzylamine. Poly(vinylbenzylactonamide-co-vinylbenzylbiotinamide), p(VLA-co-VBA) were synthesized through radical polymerization from the synthetic monomers(VLA-VBA) by using various mole ratio. The percentages of yield were 67~71%. The copolymers were found amphlphilic which had hydrophilic lactose, hydrophobic vinylbenzyl and biotin site within the structure. IR and $^{13}C-NMR$ analysis on the monomers and copolymer were carried out.

• Analytical Science and Technology
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• v.18 no.6
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• pp.460-468
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• 2005

The biotin-avidin complex, as a model recognition system, has been constructed through N-hydroxysuccinimide(NHS) reaction on a variety of substrates such as a smooth Au film, electrochemically roughened Au electrode and chemically modified mica. Stepwise self-assembled monolayers (SAMs) of biotin-avidin system were characterized by surface-enhanced resonance Raman scattering (SERRS) spectroscopy, atomic force microscopy (AFM) and surface plasmon resonance (SPR). A strong SERRS signal of rhodamine tags labeled in avidin from the SAMs on a roughened gold electrode indicated the successful complex formation of stepwise biotin-avidin recognition system. AFM images showed the circular shaped avidin aggregates (hexamer) with ca. $60{\AA}$ thick on the substrate, corresponding to one layer of avidin. The surface coverage and concentration of avidin molecules were estimated to be 90% and $7.5{\times}10^{-12}mol/cm^2$, respectively. SPR technique allowed one to monitor the surface reaction of the specific recognition with high sensitivity and precision.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.37-42
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• 1993

Surface proteins of Trichomonqs unginnlis (T vqsinalis) were analyzed to study the antigenic variation. The surface proteins of protozoa were labelled by N- hydrokysuccinimide-biotin (NHS-biotins, the NHS-biotin-labelled proteins were immunoprecipitated with rabbit antiserum to purifjr the antigenic fractions and analysed by SDS-PAGE plus electroblotting. The results obtained in this study were as follows; Biotinylated T. uaginalis-proteins obtained from intact cell and cells disrupted prior to labelling were detected by antibiotin-peroxidase in Western blots. Labelled proteins were immunoprecipitated by T. vcqinalis-immunized rabbit serum and the six bands with, the molecular weights of 46, 60, 68, 90, 130 and 220 kDa were identified as having antigenicity. T unginalis HY-1,HY-15 and ATCC 50148 were immunoprecipitated by immune rabbit serum after biotinylation and there were no difference from antigenic bands among these strains by this tehchnique. In conclusion with the results obtained in the present study, it was assumed that surface proteins of T vaqinclis were labelled by biotinylation and the six labelled bands at 46, 60, 68, 90, 130 and 220 kDa in their molecular weight were identified as having antigenicity by immunoprecipitation (IPI and this biotinylation-IP technique may be used for further study of surface antigen of T vaginalis.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1209-1216
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• 2022

To better understand the effects of PEGylation and biotinylation on the delivery efficiency of proteins, the cationic protein lysozyme (LZ) and anionic protein bovine serum albumin (BSA) were chemically conjugated with poly(ethylene glycol) (PEG) and biotin-PEG to primary amine groups of proteins using N-hydroxysuccinimide reactions. Four types of protein conjugates were successfully prepared: PEGylated LZ (PEG-LZ), PEGylated BSA (PEG-BSA), biotin-PEG-conjugated LZ (Bio-PEG-LZ), and biotin-PEG-conjugated BSA (Bio-PEG-BSA). PEG-LZ and Bio-PEG-LZ exhibited a lower intracellular uptake than that of LZ in A549 human lung cancer cells (in a two-dimensional culture). However, Bio-PEG-BSA showed significantly improved intracellular delivery as compared to that of PEG-BSA and BSA, probably because of favorable interactions with cells via biotin receptors. For A549/fibroblast coculture spheroids, PEG-LZ and PEG-BSA exhibited significantly decreased tissue penetration as compared with that of unmodified proteins. However, Bio-PEG-BSA showed tissue penetration comparable to that of unmodified BSA. In addition, citraconlyated LZ (Cit-LZ) showed reduced spheroid penetration as compared to that of LZ, probably owing to a decrease in protein charge. Taken together, chemical conjugation of targeting ligands-PEG to anionic proteins could be a promising strategy to improve intracellular delivery and in vivo activity, whereas modifications of cationic proteins should be more delicately designed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.55-59
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• 2000

A specific and sensitive sandwich enzyme-immunoassay (EIA) using Avidin-Biotin complex was developed for the measurement of GTH II levels in pituitary content and pituitary cell culture medium of the rainbow trout-(Oncorhpchus mykiss). Biotin-salmon GTH II rabbit IgG (sefondary antibody) wai purified by a protein A sepharose affinity chromatography column and that was biotinylated by using Biotin-N-hydroxysuccinimide ofter (BNHS). Non-biotin salmon GTH II rabbit IgG (first antibody) was obtained only through a protein A sepharose affinity chromatography column. The assay was performed by the so-called 'sandwich' method using a microtiter plate, A dose-response curve was obtained between $0.12 to 125 ng/ml$ of salmon GTH II. The displacement curves for pituitary extraction and pituitary cell culture medium of testosterone-treated rainbow trout were Parallel to the standard curie. The intra-assay and inter-assay coefficients of variation (CV) were $8.2{\%} (N=5) and 12.5{\%} (N=6)$, respectively, This assay system was used to measure the amount of GTH II that accumulated in the culture medium of dispersed pituitary cells in testosterone-treated immature rainbow trout, The accumulation was increased with the amount or salmon gonadotropin-releasing hormone. GTH II values determined by the present method were well correlated with those determined by radioimmunoassay. As a result, this assay system was found to be suitable for the measurement of GTH II for pituitary extraction and pituitary culture medium in many salmonid fishes.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.243-248
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• 1994

Plasma membrane proteins of a Korean isolate of Trichomonus vofinalis HY-1 were fractionated for antigen analysis. Homogenates of T. vaginalis were fractionated by the differential centrifugation using sucrose step-gradient method. The interface layer from the 25%/45% sucrose was collected as a plasma membrane fraction and its purity was examined by transmission electron microscopy. The antigenicity of plasma membrane fraction was analysed by enzyme-linked immunoelectrotransfer blot technique with immune rabbit serum and compared with surface antigen labelled with N. hydroxysuccinimide-biotin. The fluffy fraction of 25%/45% sucrose interface was homogeneous and membrane particles were present as extended sheet and concentric vesicles showing typical trilamellar appearance under transmission electron microscope. Seven fractions at 40, 50, 60, 110, 130, 140 and 150 kDa were identified as the antigenic membrane proteins in EITB with anti HY-1 rabbit serum. The common band at 60 kDa was detected both in antigenic fractions of plasma membrane and surface protein labelled with NHS-biotin. This result indicates that this protein is considered as a major surface antigen of T. vaginalis. The role of this surface antigen at 60 kDa should be studied further.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.70-74
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• 2003

The heterogeneous bioluminescence immunoassay for digoxin was developed using photoprotein, native aequorin as a label and the site-directed immobilization technique based on avidin/biotin interaction. Aequorin is a bioluminescence protein, originally isolated from the jellyfish Aequoria Victoria and an attractive label in analytical applications because of sensitive detection due to virtually no background bioluminescent signal. Digoxin is a cardioactive drug, and its therapeutic level in serum is at low concentration with very narrow therapeutic index. The aequorin-digoxigenin conjugates were synthesized by the N-hydroxysuccinimide ester method and characterized in terms of bioluminescent residual activity. The resulting dose-response curve shows that the detection limit is $1.0\;{\times}\;10^{-10}\;M$ and a dynamic range is three orders of magnitude, which was obtained by $1.0\;{times}\;10^{-10}\;M$ conjugate and 0.9 μg/mL anti-digoxin antibody. Three structurally similar molecules to digoxin were examined for their cross-reactivity. None of these three compounds showed any crossreactivity with digoxin antibody employed in this study. Standard amounts of digoxin corresponding to the therapeutic range were spiked into the each serum solution. Study of the serum matrix effect indicated that correlation coefficient shows good agreement between luminescence light intensity between in buffer and in serum.