Kinetic analysis of a high-affinity antibody/antigen interaction performed by planar waveguide fluorescence immunosensor

RSC Advances ◽  
2016 ◽  
Vol 6 (17) ◽  
pp. 13837-13845 ◽  
Author(s):  
Hongli Guo ◽  
Xiaohong Zhou ◽  
Yan Zhang ◽  
Chunmei Gu ◽  
Baodong Song ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Planar Waveguide ◽  
Biomolecular Interactions ◽  
Optical Biosensors ◽  
High Affinity ◽  
Antigen Interaction

Methods based on optical biosensors for the investigation of biomolecular interactions between high-affinity antibodies and antigens has advanced over the last years.

Kinetic analysis of a high-affinity antibody/antigen interaction performed by multiple Biacore users

2006 ◽  
Vol 352 (2) ◽  
pp. 208-221 ◽  
Author(s):  
Phinikoula S. Katsamba ◽  
Iva Navratilova ◽  
Maria Calderon-Cacia ◽  
Linsey Fan ◽  
Kevin Thornton ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
High Affinity ◽  
Antigen Interaction

Buffer systems variably affect the interaction of norepinephrine with brain Na+–K+ ATPase

1988 ◽  
Vol 66 (8) ◽  
pp. 1035-1040
Author(s):  
S. J. Mihic ◽  
P. H. Wu ◽  
H. Kalant
Keyword(s):  
Atpase Activity ◽  
Kinetic Analysis ◽  
Rat Brain ◽  
Reaction Conditions ◽  
Synaptosomal Membrane ◽  
High Affinity

The reported effects of norepinephrine (NE) on brain Na+–K+ ATPase are quite variable. Different investigators have reported activation, inhibition, or no effect. An investigation of the importance of reaction conditions on brain Na+–K+ ATPase activity was undertaken to resolve some of these discrepancies. Using porcine cerebral cortical Na+–K+ ATPase and rat brain synaptosomal membrane preparations, it was observed that NE strongly inhibited brain Na+–K+ ATPase in Tris–HCl buffer. This inhibition of the enzyme was reversed by the addition of EDTA. In contrast, NE did not significantly inhibit Na+–K+ ATPase in imidazole–glycylglycine and Krebs–Ringer–phosphate buffers. This buffer dependence of NE inhibition of the enzyme was consistently demonstrated with three different established methods for phosphate measurement. Kinetic analysis indicated that NE, in Tris–HCl buffer, inhibited the enzyme noncompetitively at high affinity, and competitively at low affinity, ATP substrate sites.

scholarly journals The Saccharomyces cerevisiae YCC5(YCL025c) Gene Encodes an Amino Acid Permease, Agp1, Which Transports Asparagine and Glutamine

1998 ◽  
Vol 180 (9) ◽  
pp. 2556-2559 ◽  
Author(s):  
James L. Schreve ◽  
Jennifer K. Sin ◽  
Jinnie M. Garrett
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Kinetic Analysis ◽  
Amino Acid Permease ◽  
High Affinity ◽  
Nitrogen Repression

ABSTRACT The yeast YCC5 gene encodes a putative amino acid permease and is homologous to GNP1 (encoding a high-affinity glutamine permease). Using strains with disruptions in the genes for multiple permeases, we demonstrated that Ycc5 (which we have renamed Agp1) is involved in the transport of asparagine and glutamine, performed a kinetic analysis of this activity, and showed that AGP1 expression is subject to nitrogen repression.

scholarly journals Structural and kinetic analysis of the COP9-Signalosome activation and the cullin-RING ubiquitin ligase deneddylation cycle

2016 ◽  
Author(s):  
Ruzbeh Mosadeghi ◽  
Kurt M. Reichermeier ◽  
Martin Winkler ◽  
Anne Schreiber ◽  
Justin M. Reitsma ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Ubiquitin Ligase ◽  
Conformational Changes ◽  
Active Site ◽  
Ring Domain ◽  
Cop9 Signalosome ◽  
Active Complex ◽  
High Affinity ◽  
Terminal Domains

AbstractThe COP9-Signalosome (CSN) regulates cullin–RING ubiquitin ligase (CRL) activity and assembly by cleaving Nedd8 from cullins. Free CSN is autoinhibited, and it remains unclear how it becomes activated. We combine structural and kinetic analyses to identify mechanisms that contribute to CSN activation and Nedd8 deconjugation. Both CSN and neddylated substrate undergo large conformational changes upon binding, with important roles played by the N-terminal domains of Csn2 and Csn4 and the RING domain of Rbx1 in enabling formation of a high affinity, fully active complex. The RING domain is crucial for deneddylation, and works in part through conformational changes involving insert-2 of Csn6. Nedd8 deconjugation and re-engagement of the active site zinc by the autoinhibitory Csn5 glutamate-104 diminish affinity for Cul1/Rbx1 by ~100-fold, resulting in its rapid ejection from the active site. Together, these mechanisms enable a dynamic deneddylation-disassembly cycle that promotes rapid remodeling of the cellular CRL network.

scholarly journals Determination of the mechanism of reaction for bile acid: CoA ligase

1994 ◽  
Vol 304 (3) ◽  
pp. 945-949 ◽  
Author(s):  
M Kelley ◽  
D A Vessey
Keyword(s):  
Kinetic Analysis ◽  
Substrate Inhibition ◽  
Liver Microsomes ◽  
Competitive Inhibitor ◽  
High Affinity ◽  
Coa Ligase ◽  
Absolute Requirement ◽  
Mechanism Of Reaction ◽  
Ping Pong

The reaction of cholic acid, CoA and ATP to yield cholyl-CoA was investigated by kinetic analysis of the reaction as catalysed by guinea pig liver microsomes. The enzyme has an absolute requirement for divalent cation for activity so all kinetic analyses were carried out in excess Mn2+. A trisubstrate kinetic analysis was conducted by varying, one at a time ATP cholate and CoA. Both ATP and cholate gave parallel double reciprocal plots versus CoA, which indicates a ping-pong mechanism with either pyrophosphate or AMP leaving prior to the binding of CoA. Addition of pyrophosphate to the assays changed the parallel plots to intersecting ones; addition of AMP did not. This indicates that pyrophosphate is the first product. The end-product, AMP, was a competitive inhibitor versus ATP, as was cholyl-CoA at saturating concentrations of cholate. Both AMP and cholyl-CoA were uncompetitive inhibitors versus CoA. Based on this information, it was concluded that the reaction follows a bi uni uni bi ping-pong mechanism with ATP binding first, and with the release of the final products, AMP and cholyl-CoA, being random. CoA showed substrate inhibition at high but non-saturating concentrations and this inhibition was competitive versus ATP, which is consistent with the predicted ping-pong mechanism. The ability of cholyl-CoA, but not cholate or CoA, to bind with high affinity to the free enzyme was suggestive of a high affinity of the enzyme for the thioester link.

scholarly journals Down's syndrome fibroblasts exhibit enhanced inositol uptake

1990 ◽  
Vol 270 (1) ◽  
pp. 119-123 ◽  
Author(s):  
B R Fruen ◽  
B R Lester
Keyword(s):  
Plasma Membrane ◽  
Kinetic Analysis ◽  
Trisomy 21 ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Maximal Velocity ◽  
High Affinity ◽  
Proportional Increase ◽  
Inositol Uptake ◽  
Inositol Metabolism

The inositol metabolism of Down's syndrome (DS, trisomy 21) skin fibroblasts was examined. We report that DS cells accumulated [3H]inositol 2-3-fold faster than did other aneuploid or diploid controls. In contrast, trisomy 21 did not affect the uptake of choline, serine or glucose. Kinetic analysis demonstrated an increased maximal velocity of high-affinity, Na(+)-dependent, inositol transport, consistent with the expression of higher numbers of transporters by DS cells. Enhanced uptake was accompanied by a proportional increase in the incorporation of radiolabelled inositol into phospholipid. We suggest that an imbalance of inositol metabolism may contribute to plasma membrane abnormalities characteristic of DS cells.

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