Search results for "HAp"
showing 10 items of 2767 documents
Structure and function of the vacuolar Ccc1/VIT1 family of iron transporters and its regulation in fungi
2020
Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/V…
Monoclonal antibody-based immunoassays for cyprodinil residue analysis in QuEChERS-based fruit extracts
2015
Cyprodinil is among the most common agrochemical residues found in highly perishable fruits, such as strawberries. In the present study, high-affinity monoclonal antibodies to this anilinopyrimidine fungicide were raised for the first time with the aim to produce valuable immunochemical analytical assays. Cyprodinil bioconjugates and the generated novel monoclonal antibodies were employed for sensitive competitive immunoassay development in two different formats. The limits of detection of the optimized assays were 20 and 30 ng L-1 for the indirect and direct assay, respectively. Influence over assay parameters of different physicochemical factors was studied. Strawberry samples were extrac…
Hapten Synthesis and Polyclonal Antibody-Based Immunoassay Development for the Analysis of Forchlorfenuron in Kiwifruit
2010
High-affinity polyclonal antibodies directed against the synthetic cytokinin forchlorfenuron (CPPU) were produced from three immunizing haptens with equivalent spacer arms located at different positions. A competitive immunoassay was developed with a limit of detection in buffer of 12.42 +/- 3.06 ng/L. In addition, the ability of the produced antibodies to recognize a set of synthetic CPPU analogues was studied. It was evidenced that the linker position had a strong impact on the specificity of the generated polyclonals, which were more sensitive to changes at moieties of the target analyte located furthest from the derivatization site of the immunogen. Finally, matrix effects of gold and g…
Keyhole limpet hemocyanin (KLH): a biomedical review
1999
In this review we present a broad survey of fundamental scientific and medically applied studies on keyhole limpet hemocyanin (KLH). Commencing with the biochemistry of KLH, information on the biosynthesis and biological role of this copper-containing respiratory protein in the marine gastropod Megathura crenulata is provided. The established methods for the purification of the two isoforms of KLH (KLH1 and KLH2) are then covered, followed by detailed accounts of the molecular mass determination, functional unit (FU) structure, carbohydrate content, immunological analysis and recent aspects of the molecular genetics of KLH. The transmission electron microscope (TEM) has contributed signific…
Haptens, bioconjugates, and antibodies for penthiopyrad immunosensing
2014
4 pages, 1 table, 2 figures.
Forchlorfenuron-mimicking haptens: From immunogen design to antibody characterization by hierarchical clustering analysis
2011
To obtain highly-specific and selective forchlorfenuron binders, a collection of functionalized derivatives with different spacer arm locations and lengths was prepared. By immunization with target-mimicking haptens, a large battery of monoclonal and polyclonal antibodies against this synthetic cell regulator was produced and exhaustively characterized in two immunoassay formats using homologous and heterologous conjugates. Antibodies with IC50 values lower than 0.3 nM were successfully raised from the prepared immunogens, thus evidencing the efficacy of the explored strategies. In order to identify significant epitopes in the antibody-antigen interaction, a series of new chemical forchlorf…
Immunoreagents and competitive assays to fludioxonil
2014
Fludioxonil is a new-generation fungicide widely used for postharvest fruit protection. The aim of this study was to produce hitherto unreported immunoreagents for Fludioxonil analysis by immunoassay. Derivatives of this agrochemical were synthesized with different linker tethering sites. Those functionalized haptens were activated, and the purified active esters were efficiently conjugated to different carrier proteins for immunogen and assay antigen preparation. Antibodies to Fludioxonil were raised in rabbits, and their selectivity and affinity were characterized, revealing the significance of the linker. Those antibodies were evaluated using homologous and heterologous conjugates by dir…
Hapten synthesis, monoclonal antibody generation, and development of competitive immunoassays for the analysis of picoxystrobin in beer.
2010
Abstract This paper describes the original synthesis of a functionalized derivative of the fungicide picoxystrobin and the generation of the first reported monoclonal antibodies against this strobilurin pesticide. The synthetic hapten was prepared by total synthesis from commercial chemicals and incorporating the spacer arm through a carbon–carbon single bond. Also, to obtain the immunogen, an uncommon hapten activation strategy based on N,N′-disuccinimidyl carbonate was employed, affording high activation yields and clean and reproducible coupling results. With these immunoreagents, two enzyme-linked immunosorbent assays (ELISAs) were developed: a competitive one-step assay using the antib…
Production of specific antibodies and development of a non-isotopic immunoassay for carbamazepine by the carbonyl metallo-immunoassay (CMIA) method.
1995
Abstract As part of our ongoing work to extend the range of applications of the non-isotopic carbonyl metalloimmunoassay (CMIA), previously developed in our laboratory, we describe here the first CMIA study of carbamazepine. The CMIA method uses a metal carbonyl complex as a non-isotopic tracer, and in this case we chose to employ the dicobalt hexacarbonyl moiety (Co2(CO)6) attached to an alkyne. Two organometallic tracers, 3 and 7 , were synthesized, differentiated by the nature and length of the spacer arm of the Co2(CO)6 moiety. Two different coupling methods were subsequently used to synthesize the immunogens 1 and 2, the first one used a carbodiimide, while the second, employed dimethy…
C4 DNA RFLP reference typing report.
1990
One hundred and three individual DNA samples (including 23 families) were studied at the gene level during the reference typing of the fourth component of human complement at the VIth Complement Genetics Workshop in Mainz (1989). All samples were analyzed with the restriction enzyme Taq I and with two DNA probes recognizing the 5' ends of both C4 genes and the two adjacent 21-hydroxylase genes. This RFLP is informative for the number of C4 genes as well as for their respective gene size. We found a high degree of variation regarding the number of C4 genes, i.e. haplotypes with 1-3 structural C4 genes of 16 or 22 kb size. By correlating these haplotypes to the complotypes obtained by protein…