scholarly journals Kinetics and proposed mechanism of the reaction of an immunoinhibition, particle-enhanced immunoassay

1997 ◽  
Vol 43 (12) ◽  
pp. 2384-2389 ◽  
Author(s):  
John C Thompson ◽  
Alan R Craig ◽  
Carol L Davey ◽  
David J Newman ◽  
Michele L Lonsdale ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Maximum Rate ◽  
Colloidal Stability ◽  
Kinetic Studies ◽  
Latex Agglutination ◽  
Equivalence Point ◽  
Colloidal Aggregation ◽  
Free Sample ◽  
Identical Fashion ◽  
Mechanism Of The Reaction

Abstract We report kinetic studies on the reaction of a latex agglutination immunoassay used to quantify phenytoin in serum. In this assay, polystyrene particles with a covalently attached analog of phenytoin react with an antiphenytoin monoclonal antibody to form light-scattering aggregates, with the rate of this reaction being decreased by addition of phenytoin from sample. In the absence of free (sample) phenytoin, this reaction did not exhibit a maximum rate of agglutination in the presence of excess antibody, i.e., an equivalence point. Furthermore, agglutination was inhibitable by free phenytoin even when the latter was added after agglutination of particles with antibody had begun. Most significantly, the immunoagglutination proceeded in an identical fashion with monovalent F(ab) fragment. These data are consistent with low-affinity immunospecific particle–antibody complexation, which then induces colloidal aggregation, without requiring immunospecific bridging by antibody molecules. The described mechanism is not generalizable to all latex agglutination immunoassays, although disturbance of colloidal stability may be a component in most assays.

scholarly journals ATP and Tri-Polyphosphate (TPP) Suppress Protein Aggregate Growth by a Supercharging Mechanism

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1646
Author(s):  
Jordan Bye ◽  
Kiah Murray ◽  
Robin Curtis
Keyword(s):  
Protein Interactions ◽  
Electrostatic Interactions ◽  
Colloidal Stability ◽  
Conformational Stability ◽  
Kinetic Studies ◽  
Structural Factors ◽  
Protein Protein Interactions ◽  
Protein Aggregate ◽  
Aggregate Growth

A common strategy to increase aggregation resistance is through rational mutagenesis to supercharge proteins, which leads to high colloidal stability, but often has the undesirable effect of lowering conformational stability. We show this trade-off can be overcome by using small multivalent polyphosphate ions, adenosine triphosphate (ATP) and tripolyphosphate (TPP) as excipients. These ions are equally effective at suppressing aggregation of ovalbumin and bovine serum albumin (BSA) upon thermal stress as monitored by dynamic and static light scattering. Monomer loss kinetic studies, combined with measurements of native state protein–protein interactions and ζ-potentials, indicate the ions reduce aggregate growth by increasing the protein colloidal stability through binding and overcharging the protein. Out of three additional proteins studied, ribonuclease A (RNaseA), α-chymotrypsinogen (α-Cgn), and lysozyme, we only observed a reduction in aggregate growth for RNaseA, although overcharging by the poly-phosphate ions still occurs for lysozyme and α-Cgn. Because the salts do not alter protein conformational stability, using them as excipients could be a promising strategy for stabilizing biopharmaceuticals once the protein structural factors that determine whether multivalent ion binding will increase colloidal stability are better elucidated. Our findings also have biological implications. Recently, it has been proposed that ATP also plays an important role in maintaining intracellular biological condensates and preventing protein aggregation in densely packed cellular environments. We expect electrostatic interactions are a significant factor in determining the stabilizing ability of ATP towards maintaining proteins in non-dispersed states in vivo.

Listeriolysin O-Based Latex Agglutination Test for the Rapid Detection of Listeria monocytogenes in Foods

1997 ◽  
Vol 60 (9) ◽  
pp. 1038-1040 ◽  
Author(s):  
GHASSAN M. MATAR ◽  
PEGGY S. HAYES ◽  
WILLIAM F. BIBB ◽  
BALA SWAMINATHAN
Keyword(s):  
Monoclonal Antibody ◽  
Listeria Monocytogenes ◽  
Rapid Detection ◽  
Rapid Test ◽  
Food Samples ◽  
Cross Reactivity ◽  
Latex Agglutination ◽  
Listeriolysin O ◽  
Agglutination Assay ◽  
Latex Beads

A latex agglutination-based test for the rapid detection of Listeria monocytogenes in foods was developed. An antilisteriolysin O (LLO) monoclonal antibody (HID5E12D7; IgG2b) covalently bound to polystyrene amidine-modified latex beads was used in a slide agglutination assay. The latex reagent detected 0.1 ng/ml of LLO in phosphate-buffered saline plus bovine serum albumin. It reacted with culture supernatants of L. monocytogenes but not with other Listeria species or Streptococcus groups A through G. The listeriolysin O latex agglutination assay (LLOLAT) was applied to 24-h and 48-h USDA primary enrichment cultures of 208 food samples obtained from refrigerators of listeriosis patients enrolled in a study to determine the role of foods in sporadic listeriosis. Of 19 samples positive by cultural techniques, 17 were positive by the LLOLAT. Cultures with low (<0.3 CFU/g) levels of L. monocytogenes were positive in the LLOLAT. No cross-reactivity occurred when using a heterogeneous monoclonal antibody. The LLOLAT is a sensitive, specific and rapid test and may be useful for screening foods for L. monocytogenes.

A new diagnostic method for adenoma malignum and related lesions: latex agglutination test with a new monoclonal antibody, HIK1083

2001 ◽  
Vol 312 (1-2) ◽  
pp. 231-233 ◽  
Author(s):  
Keiko Ishii ◽  
Toshiko Kumagai ◽  
Makoto Kurihara ◽  
Tanri Shiozawa ◽  
Hiroshi Noguchi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Diagnostic Method ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Latex Agglutination Test ◽  
Adenoma Malignum

scholarly journals Fouling of an anion exchange chromatography operation in a monoclonal antibody process: Visualization and kinetic studies

2013 ◽  
Vol 110 (9) ◽  
pp. 2425-2435 ◽  
Author(s):  
Edward J. Close ◽  
Jeffrey R. Salm ◽  
Timothy Iskra ◽  
Eva Sørensen ◽  
Daniel G. Bracewell
Keyword(s):  
Monoclonal Antibody ◽  
Anion Exchange ◽  
Kinetic Studies ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Process Visualization

A latex agglutination assay for D dimer: evaluation and application to the diagnosis of thrombotic disease.

1987 ◽  
Vol 33 (10) ◽  
pp. 1837-1840 ◽  
Author(s):  
C J Hillyard ◽  
A S Blake ◽  
K Wilson ◽  
D B Rylatt ◽  
S Miles ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Degradation Products ◽  
Reference Interval ◽  
Latex Agglutination ◽  
Agglutination Assay ◽  
Fibrin Degradation Products ◽  
Pathological Conditions ◽  
D Dimer ◽  
Latex Agglutination Assay ◽  
Apparently Healthy

Abstract Although latex agglutination assays have been used for some years to diagnose thrombotic disorders, only recently has it been possible to measure specifically the products of fibrin breakdown in the presence of fibrinogen degradation products, by using monoclonal antibodies. We have evaluated a preparation of latex particles coupled to the monoclonal antibody DD-3B6/22, which is specific for cross-linked fibrin degradation products (XDP) and allows accurate discrimination between normal and pathological conditions. Of samples from 515 apparently healthy volunteers, 97.7% failed to agglutinate the latex; the normal reference interval for XDP determined by enzyme immunoassay was less than 78-320 micrograms/L. The use of different anticoagulants with or without the addition of a protease inhibitor had no significant effects on the results of the latex assay. The latex preparation provides a useful, rapid diagnostic tool for assaying small numbers of samples or as an emergency test.

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