Determination of the reactive sulfhydryl groups in heme proteins with 4,4′-dipyridinedisulfide

Ampulski, Robert S.; Ayers, Valborg E.; Morell, Samuel A.

doi:10.1016/0003-2697(69)90118-3

Cited by 66 publications

(43 citation statements)

References 12 publications

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“…Analytical Methods: The thiolation of Hb by 2-iminothiolane was followed by estimating the number of thiol groups formed as a function of time using 4,4'-dithiopyridine (4-PDS), as described by Ampulski et al (31).…”

Section: Vasoactivity Of Pegylated Hbsmentioning

confidence: 99%

WITHDRAWN: PEGylated hemoglobin: Role of surface configuration of PEG for the modulation of hemoglobin vasoactivity

Manjula

2004

Journal of Biological Chemistry

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Section: Vasoactivity Of Pegylated Hbsmentioning

confidence: 99%

WITHDRAWN: PEGylated hemoglobin: Role of surface configuration of PEG for the modulation of hemoglobin vasoactivity

Manjula

2004

Journal of Biological Chemistry

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“…␤93 of ␣-nitrosyl Hb Derivatives toward 4-PDS-This method (21) was carried out as described previously (22,23), with the following modifications for a quantitative measurement. A standard solution of 4-PDS was prepared by dissolving approximately 10 mg in 10 ml of deoxygenated distilled water at 60°C.…”

Section: Kinetic Studies Of the Sulfhydryl Reactivity Of Cysmentioning

confidence: 99%

Electron Paramagnetic Resonance and Oxygen Binding Studies of α-Nitrosyl Hemoglobin

Yonetani

Tsuneshige

Zhou

et al. 1998

Journal of Biological Chemistry

135

110

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␣-Nitrosyl hemoglobin, ␣(Fe-NO) 2 ␤(Fe) 2 , which is frequently observed upon reaction of deoxy hemoglobin with limited quantities of NO in vitro as well as in vivo, has been synthetically prepared, and its reaction with O 2 has been investigation by EPR and thermodynamic equilibrium measurements. ␣-Nitrosyl hemoglobin is relatively stable under aerobic conditions and undergoes reversible O 2 binding at the heme sites of its ␤-subunits. Its O 2 binding is coupled to the structural/functional transition between T-(low affinity extreme) and R-(high affinity) states. This transition is linked to the reversible cleavage of the heme Fe-proximal His bonds in the ␣(Fe-NO) subunits and is sensitive to allosteric effectors, such as protons, 2,3-biphosphoglycerate, and inositol hexaphosphate. In fact, ␣(Fe-NO) 2 ␤(Fe) 2 is exceptionally sensitive to protons, as it exhibits a highly enhanced Bohr effect. The total Bohr effect of ␣-nitrosyl hemoglobin is comparable to that of normal hemoglobin, despite the fact that the oxygenation process involves only two ligation steps. All of these structural and functional evidences have been further confirmed by examining the reactivity of the sulfhydryl group of the Cys ␤93 toward 4,4-dipyridyl disulfide of several ␣-nitrosyl hemoglobin derivatives over a wide pH range, as a probe for quaternary structure. Despite the halved O 2 -carrying capacity, ␣-nitrosyl hemoglobin is fully functional (cooperative and allosterically sensitive) and could represent a versatile low affinity O 2 carrier with improved features that could deliver O 2 to tissues effectively even after NO is sequestered at the heme sites of the ␣-subunits. It is concluded that the NO bound to the heme sites of the ␣-subunits of hemoglobin acts as a negative allosteric effector of Hb and thus might play a role in O 2 /CO 2 transport in the blood under physiological conditions.

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“…The column was eluted using PBS at pH 7.4 and a flow rate of 0.5 mL/min, and the effluent was monitored at absorbance 540 nm. The reactivity and number of thiol groups on Hb samples were estimated by reaction with 4, 4’-dithiopyridine (4-PDS) (Aldrich Chemical Co.) according to Ampulski et al (Ampulski et al 1969). …”

Section: Methodsmentioning

confidence: 99%

PEGylation of αα-Hb using succinimidyl propionic acid PEG 5K: Conjugation chemistry and PEG shell structure dictate respectively the oxygen affinity and resuscitation fluid like properties of PEG αα-Hbs

Meng

Tsai²,

Intaglietta³

et al. 2014

Artificial Cells, Nanomedicine, and Biotechnology

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PEGylation of intramolecularly crosslinked Hb has been studied here to overcome the limitation of dissociation of Hb tetramers. New hexa and deca PEGylated low oxygen affi nity PEG-αα-Hbs have been generated. Infl uence of PEG conjugation chemistry and the PEG shell structure on the functional properties as well as PEGylation induced plasma expander like properties of the protein has been delineated. The results have established that in the design of PEG-Hbs as oxygen therapeutics, the infl uence of conjugation chemistry and the PEG shell structure on the oxygen affi nity of Hb needs to be optimized independently besides optimizing the PEG shell structure for inducing resuscitation fluid like properties.

show abstract

Determination of the reactive sulfhydryl groups in heme proteins with 4,4′-dipyridinedisulfide

Cited by 66 publications

References 12 publications

WITHDRAWN: PEGylated hemoglobin: Role of surface configuration of PEG for the modulation of hemoglobin vasoactivity

WITHDRAWN: PEGylated hemoglobin: Role of surface configuration of PEG for the modulation of hemoglobin vasoactivity

Electron Paramagnetic Resonance and Oxygen Binding Studies of α-Nitrosyl Hemoglobin

PEGylation of αα-Hb using succinimidyl propionic acid PEG 5K: Conjugation chemistry and PEG shell structure dictate respectively the oxygen affinity and resuscitation fluid like properties of PEG αα-Hbs

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