Effects of photoproducts on the binding properties of protoporphyrin IX to proteins

Brancaleon, Lorenzo; Moseley, Harry

doi:10.1016/s0301-4622(02)00035-2

Cited by 58 publications

(49 citation statements)

References 27 publications

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“…In addition, the spectral data indicated that the tetrapyrrole ring of hematin was bound to IgG in such a way that one of the planes of the molecule remained fully exposed to the solvent. Our findings are in agreement with previous studies demonstrating that protoporphyrin IX (compound similar to hematin but without iron) is able to bind to Ig molecules (49,50). It was shown in previous studies (49,50) that protoporphyrin binds to Ig molecules in a similar way as was observed for hematin in this study.…”

Section: Mechanisms Of Heme-induced Enlargement Of the Availablesupporting

confidence: 94%

“…Our findings are in agreement with previous studies demonstrating that protoporphyrin IX (compound similar to hematin but without iron) is able to bind to Ig molecules (49,50). It was shown in previous studies (49,50) that protoporphyrin binds to Ig molecules in a similar way as was observed for hematin in this study. Therefore, it seems likely that Igs have an inherent capability to bind heme.…”

Section: Mechanisms Of Heme-induced Enlargement Of the Availablesupporting

confidence: 94%

See 1 more Smart Citation

Antibodies Use Heme as a Cofactor to Extend Their Pathogen Elimination Activity and to Acquire New Effector Functions

Dimitrov

Roumenina

Doltchinkova

et al. 2007

Journal of Biological Chemistry

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Various pathological processes are accompanied by release of high amounts of free heme into the circulation. We demonstrated by kinetic, thermodynamic, and spectroscopic analyses that antibodies have an intrinsic ability to bind heme. This binding resulted in a decrease in the conformational freedom of the antibody paratopes and in a change in the nature of the noncovalent forces responsible for the antigen binding. The antibodies use the molecular imprint of the heme molecule to interact with an enlarged panel of structurally unrelated epitopes. Upon heme binding, monoclonal as well as pooled immunoglobulin G gained an ability to interact with previously unrecognized bacterial antigens and intact bacteria. IgG-heme complexes had an enhanced ability to trigger complement-mediated bacterial killing. It was also shown that heme, bound to immunoglobulins, acted as a cofactor in redox reactions. The potentiation of the antibacterial activity of IgG after contact with heme may represent a novel and inducible innate-type defense mechanism against invading pathogens.

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Section: Mechanisms Of Heme-induced Enlargement Of the Availablesupporting

confidence: 94%

Section: Mechanisms Of Heme-induced Enlargement Of the Availablesupporting

confidence: 94%

Antibodies Use Heme as a Cofactor to Extend Their Pathogen Elimination Activity and to Acquire New Effector Functions

Dimitrov

Roumenina

Doltchinkova

et al. 2007

Journal of Biological Chemistry

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“…It can interact with many proteins, [23][24][25] and serves as a photodynamic agent in cancer therapy. 26,27 PPIX tends to aggregate into micelles in aqueous solution with low fluorescence, 28,29 but its fluorescence intensity is drastically increased when it binds to G-quadruplexes.…”

Section: Introductionmentioning

confidence: 99%

A Label-free, Highly Sensitive and Selective Detection of Hemin Based on the Competition between Hemin and Protoporphyrin IX Binding to G-Quadruplexes

Kang

Liu

et al. 2016

ANAL. SCI.

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Herein is reported a simple and label-free fluorescent detection method for hemin based on using protoporphyrin IX (PPIX) as a fluorescent signal reporter. PPIX emits weak fluorescence in an aqueous solution. When PPIX binds to G-quadruplexes, the fluorescence intensity of PPIX is greatly increased. While in the presence of target hemin, hemin competes with PPIX toward G-quadruplexes because its affinity to G-quadruplexes is higher than that of PPIX. With the formation of the hemin-G-quadruplex complex, PPIX is released to the solution from the G-quadruplex accompanied by quenching of the fluorescence of the system. This fluorescence change of the system can be used to monitor hemin with a low detection limit of 36 nM. In addition, the possible binding sites for PPIX binding to the G-quadruplex are discussed based on competition between hemin and PPIX. What is more, this method might pave the way for applying G-quadruplexes and PPIX to more sensing systems.

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“…Immune repertoires of all healthy individuals contain antibodies (Abs) 2 that are able to interact with different low molecular weight compounds, including biologically relevant cofactors as riboflavin, FMN, FAD, heme (Fe(II) protoporphyrin IX), and ATP, as well as metal ions (1)(2)(3)(4)(5)(6)(7). The binding affinity of riboflavin, FAD, and FMN to Abs is higher than the binding affinity to known plasma transporters of heterocyclic compounds such as albumin (1,2).…”

mentioning

confidence: 99%

Prevalence and Gene Characteristics of Antibodies with Cofactor-induced HIV-1 Specificity

Lecerf

Scheel

Pashov

et al. 2015

Journal of Biological Chemistry

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Background: Normal immune repertoires have a fraction of cofactor-binding antibodies. Results: Heme exposure results in acquisition of reactivity to gp120 HIV-1 in 24% of antibodies in a seronegative immune repertoire; these antibodies have less mutated variable regions. Conclusion: Human immune repertoires contain high frequency of antibodies with cofactor-induced antigen specificities. Significance: This work enhances understanding of molecular features of heme-sensitive Abs and their contribution to diversification of the immune repertoires.

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Effects of photoproducts on the binding properties of protoporphyrin IX to proteins

Cited by 58 publications

References 27 publications

Antibodies Use Heme as a Cofactor to Extend Their Pathogen Elimination Activity and to Acquire New Effector Functions

Antibodies Use Heme as a Cofactor to Extend Their Pathogen Elimination Activity and to Acquire New Effector Functions

A Label-free, Highly Sensitive and Selective Detection of Hemin Based on the Competition between Hemin and Protoporphyrin IX Binding to G-Quadruplexes

Prevalence and Gene Characteristics of Antibodies with Cofactor-induced HIV-1 Specificity

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