Survey of the 1998 optical biosensor literature

Myszka, David G.

doi:10.1002/(sici)1099-1352(199911/12)12:6<390::aid-jmr482>3.0.co;2-8

Cited by 120 publications

(60 citation statements)

References 373 publications

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“…Densities of each fraction are indicated (in g͞ml), and a CCR5 standard was run in the far right lane to control for expression. (22). Because viral particles are likely to be negatively charged and surface plasmon resonance decays exponentially as a function of distance from the biosensor surface, we used a carboxymethylated surface that lacks a dextran matrix (Biacore C1 chip).…”

Section: Resultsmentioning

confidence: 99%

A biosensor assay for studying ligand-membrane receptor interactions: Binding of antibodies and HIV-1 Env to chemokine receptors

Hoffman

Canziani

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

105

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The HIV envelope (Env) protein mediates entry into cells by binding CD4 and an appropriate coreceptor, which triggers structural changes in Env that lead to fusion between the viral and cellular membranes. The major HIV-1 coreceptors are the seven transmembrane domain chemokine receptors CCR5 and CXCR4. The type of coreceptor used by a virus strain is an important determinant of viral tropism and pathogenesis, and virus-receptor interactions can be therapeutic targets. However, Envs from many virus strains interact with CXCR4 and CCR5 with low affinity such that direct study of this important interaction is difficult if not impossible using standard cell-surface binding techniques. We have developed an approach that makes it possible to study ligand binding to membrane proteins, including Env-coreceptor interactions, using an optical biosensor. CCR5, CXCR4, and other membrane proteins were incorporated into retrovirus particles, which were purified and attached to the biosensor surface. Binding of conformationally sensitive antibodies as well as Env to these receptors was readily detected. The equilibrium dissociation constant for the interaction between an Env derived from the prototype HIV-1 strain IIIB for CXCR4 was approximately 500 nM, explaining the difficulty in measuring this interaction using standard equilibrium binding techniques. Retroviral pseudotypes represent easily produced, stable, homogenous structures that can be used to present a wide array of single and multiple membrane-spanning proteins in a native lipid environment for biosensor studies, thus avoiding the need for detergent solubilization, purification, and reconstitution. The approach should have general applicability and can be used to correlate Env-receptor binding constants to viral tropism and pathogenesis.

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Section: Resultsmentioning

confidence: 99%

A biosensor assay for studying ligand-membrane receptor interactions: Binding of antibodies and HIV-1 Env to chemokine receptors

Hoffman

Canziani

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

105

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“…HIV-1 RT uses a tyrosine residue at position 115 (Tyr-115) as steric gate, and mutations of this residue have been shown to promote greater rNTP incorporation (10). Despite this discriminatory mechanism, it has been shown that cellular DNA polymerases do incorporate rNTPs during DNA synthesis (7,11,12). We have previously demonstrated that HIV-1 RT frequently incorporates rNTPs during DNA synthesis under macrophage dNTP/ rNTP conditions at ratio of 1 rNTP every 146 bases (4,13).…”

mentioning

confidence: 99%

Effect of Ribonucleotides Embedded in a DNA Template on HIV-1 Reverse Transcription Kinetics and Fidelity

Daddacha

Noble²,

Nguyen

et al. 2013

Journal of Biological Chemistry

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Background: Under limiting dNTP concentrations, HIV-1 RT incorporates rNTPs during DNA synthesis. Results: HIV-1 RT utilizes dNTP less efficiently around rNMPs, and mismatch extension fidelity is significantly reduced. Conclusion: Presence of an rNMP in DNA template slows HIV-1 RT-mediated DNA synthesis and reduces fidelity. Significance: This study provides insight into how rNMP incorporation during proviral DNA synthesis can affect HIV-1 replication kinetics and fidelity.

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“…3), reproducibly achieving immobilization levels of 70-200 response units relative to the ethanolamine-capped control surface. This low immobilization level was targeted to allow kinetic measurements of the system (Karlsson et al, 1991;Myszka, 1999). CYP2C9i was then exposed to soluble CYP2C9, CYP2D6, or CYP3A4 to analytically determine equilibrium dissociation constants for each dimer pair.…”

Section: Resultsmentioning

confidence: 99%

Immobilized Cytochrome P450 for Monitoring of P450-P450 Interactions and Metabolism

Bostick

Hickey

Wollenberg

et al. 2016

Drug Metabolism and Disposition

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Cytochrome P450 (P450) protein-protein interactions have been shown to alter their catalytic activity. Furthermore, these interactions are isoform specific and can elicit activation, inhibition, or no effect on enzymatic activity. Studies show that these effects are also dependent on the protein partner cytochrome P450 reductase (CPR) and the order of protein addition to purified reconstituted enzyme systems. In this study, we use controlled immobilization of P450s to a gold surface to gain a better understanding of P450-P450 interactions between three key drug-metabolizing isoforms (CYP2C9, CYP3A4, and CYP2D6). Molecular modeling was used to assess the favorability of homomeric/heteromeric P450 complex formation. P450 complex formation in vitro was analyzed in real time utilizing surface plasmon resonance. Finally, the effects of P450 complex formation were investigated utilizing our immobilized platform and reconstituted enzyme systems. Molecular modeling shows favorable binding of CYP2C9-CPR, CYP2C9-CYP2D6, CYP2C9-CYP2C9, and CYP2C9-CYP3A4, in rank order. K D values obtained via surface plasmon resonance show strong binding, in the nanomolar range, for the above pairs, with CYP2C9-CYP2D6 yielding the lowest K D , followed by CYP2C9-CYP2C9, CYP2C9-CPR, and CYP2C9-CYP3A4. Metabolic incubations show that immobilized CYP2C9 metabolism was activated by homomeric complex formation. CYP2C9 metabolism was not affected by the presence of CYP3A4 with saturating CPR concentrations. CYP2C9 metabolism was activated by CYP2D6 at saturating CPR concentrations in solution but was inhibited when CYP2C9 was immobilized. The order of addition of proteins (CYP2C9, CYP2D6, CYP3A4, and CPR) influenced the magnitude of inhibition for CYP3A4 and CYP2D6. These results indicate isoform-specific P450 interactions and effects on P450-mediated metabolism.

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Survey of the 1998 optical biosensor literature

Cited by 120 publications

References 373 publications

A biosensor assay for studying ligand-membrane receptor interactions: Binding of antibodies and HIV-1 Env to chemokine receptors

A biosensor assay for studying ligand-membrane receptor interactions: Binding of antibodies and HIV-1 Env to chemokine receptors

Effect of Ribonucleotides Embedded in a DNA Template on HIV-1 Reverse Transcription Kinetics and Fidelity

Immobilized Cytochrome P450 for Monitoring of P450-P450 Interactions and Metabolism

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