Extension arm facilitated pegylation of αα-hemoglobin with modifications targeted exclusively to amino groups

Functional and structural advantages of free cys-93(β) in the PEG-Hb adduct

Dongxia Li, Tao Hu, Belur N. Manjula, Seetharama A. Acharya

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Cys-93(β) of hemoglobin (Hb) was reversibly protected as a mixed disulfide with thiopyridine during extension arm facilitated (EAF) PEGylation and its influence on the structural and functional properties of the EAF-PEGHb has been investigated. Avoiding PEGylation of Cys-93(β) in the EAF-PEG-Hb lowers the level of perturbation of heme pocket, α1β2 interface, autoxidation, heme loss, and the O2 affinity, as compared to the EAF-PEG-Hb with PEGylation of Cys-93(β).The structural and functional advantages of reversible protection of Cys-93(β) during EAF PEGylation of oxy-Hb has been compared with Euro PEG-Hb generated by EAF PEGylation of deoxy Hb where Cys-93(β) is free in the final product. The αα-fumaryl cross-linking and EAF PEGylation targeted exclusively to Lys residues has been combined together for generation of second-generation EAF-PEG-Hb with lower oxygen affinity. The PEG chains engineered on Lys as well as PEGylation of Cys-93(β) independently contribute to the stabilization of oxy conformation of Hb and hence increase the oxygen affinity of Hb. However, oxygen affinity of the EAF-PEG-αα-Hb is more sensitive to the presence of PEGylation on Cys-93(β) than that of the EAF-PEG-Hb. The present modified EAF PEGylation platform is expected to facilitate the design of novel versions of the EAF-PEG-Hbs that can now integrate the advantages of avoiding PEGylation of Cys-93(β).

Original languageEnglish (US)
Pages (from-to)2062-2070
Number of pages9
JournalBioconjugate Chemistry
Volume20
Issue number11
DOIs
StatePublished - Nov 18 2009

Fingerprint

Hemoglobin
Functional groups
Polyethylene glycols
Hemoglobins
Oxygen
Heme
Disulfides
Conformations
PEG-hemoglobin
Stabilization

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Organic Chemistry
  • Pharmaceutical Science
  • Biomedical Engineering
  • Pharmacology

Cite this

Extension arm facilitated pegylation of αα-hemoglobin with modifications targeted exclusively to amino groups : Functional and structural advantages of free cys-93(β) in the PEG-Hb adduct. / Li, Dongxia; Hu, Tao; Manjula, Belur N.; Acharya, Seetharama A.

In: Bioconjugate Chemistry, Vol. 20, No. 11, 18.11.2009, p. 2062-2070.

Research output: Contribution to journalArticle

@article{6859ae3c91664b5594d6ea353385d8d2,
title = "Extension arm facilitated pegylation of αα-hemoglobin with modifications targeted exclusively to amino groups: Functional and structural advantages of free cys-93(β) in the PEG-Hb adduct",
abstract = "Cys-93(β) of hemoglobin (Hb) was reversibly protected as a mixed disulfide with thiopyridine during extension arm facilitated (EAF) PEGylation and its influence on the structural and functional properties of the EAF-PEGHb has been investigated. Avoiding PEGylation of Cys-93(β) in the EAF-PEG-Hb lowers the level of perturbation of heme pocket, α1β2 interface, autoxidation, heme loss, and the O2 affinity, as compared to the EAF-PEG-Hb with PEGylation of Cys-93(β).The structural and functional advantages of reversible protection of Cys-93(β) during EAF PEGylation of oxy-Hb has been compared with Euro PEG-Hb generated by EAF PEGylation of deoxy Hb where Cys-93(β) is free in the final product. The αα-fumaryl cross-linking and EAF PEGylation targeted exclusively to Lys residues has been combined together for generation of second-generation EAF-PEG-Hb with lower oxygen affinity. The PEG chains engineered on Lys as well as PEGylation of Cys-93(β) independently contribute to the stabilization of oxy conformation of Hb and hence increase the oxygen affinity of Hb. However, oxygen affinity of the EAF-PEG-αα-Hb is more sensitive to the presence of PEGylation on Cys-93(β) than that of the EAF-PEG-Hb. The present modified EAF PEGylation platform is expected to facilitate the design of novel versions of the EAF-PEG-Hbs that can now integrate the advantages of avoiding PEGylation of Cys-93(β).",
author = "Dongxia Li and Tao Hu and Manjula, {Belur N.} and Acharya, {Seetharama A.}",
year = "2009",
month = "11",
day = "18",
doi = "10.1021/bc900170e",
language = "English (US)",
volume = "20",
pages = "2062--2070",
journal = "Bioconjugate Chemistry",
issn = "1043-1802",
publisher = "American Chemical Society",
number = "11",

}

TY - JOUR

T1 - Extension arm facilitated pegylation of αα-hemoglobin with modifications targeted exclusively to amino groups

T2 - Functional and structural advantages of free cys-93(β) in the PEG-Hb adduct

AU - Li, Dongxia

AU - Hu, Tao

AU - Manjula, Belur N.

AU - Acharya, Seetharama A.

PY - 2009/11/18

Y1 - 2009/11/18

N2 - Cys-93(β) of hemoglobin (Hb) was reversibly protected as a mixed disulfide with thiopyridine during extension arm facilitated (EAF) PEGylation and its influence on the structural and functional properties of the EAF-PEGHb has been investigated. Avoiding PEGylation of Cys-93(β) in the EAF-PEG-Hb lowers the level of perturbation of heme pocket, α1β2 interface, autoxidation, heme loss, and the O2 affinity, as compared to the EAF-PEG-Hb with PEGylation of Cys-93(β).The structural and functional advantages of reversible protection of Cys-93(β) during EAF PEGylation of oxy-Hb has been compared with Euro PEG-Hb generated by EAF PEGylation of deoxy Hb where Cys-93(β) is free in the final product. The αα-fumaryl cross-linking and EAF PEGylation targeted exclusively to Lys residues has been combined together for generation of second-generation EAF-PEG-Hb with lower oxygen affinity. The PEG chains engineered on Lys as well as PEGylation of Cys-93(β) independently contribute to the stabilization of oxy conformation of Hb and hence increase the oxygen affinity of Hb. However, oxygen affinity of the EAF-PEG-αα-Hb is more sensitive to the presence of PEGylation on Cys-93(β) than that of the EAF-PEG-Hb. The present modified EAF PEGylation platform is expected to facilitate the design of novel versions of the EAF-PEG-Hbs that can now integrate the advantages of avoiding PEGylation of Cys-93(β).

AB - Cys-93(β) of hemoglobin (Hb) was reversibly protected as a mixed disulfide with thiopyridine during extension arm facilitated (EAF) PEGylation and its influence on the structural and functional properties of the EAF-PEGHb has been investigated. Avoiding PEGylation of Cys-93(β) in the EAF-PEG-Hb lowers the level of perturbation of heme pocket, α1β2 interface, autoxidation, heme loss, and the O2 affinity, as compared to the EAF-PEG-Hb with PEGylation of Cys-93(β).The structural and functional advantages of reversible protection of Cys-93(β) during EAF PEGylation of oxy-Hb has been compared with Euro PEG-Hb generated by EAF PEGylation of deoxy Hb where Cys-93(β) is free in the final product. The αα-fumaryl cross-linking and EAF PEGylation targeted exclusively to Lys residues has been combined together for generation of second-generation EAF-PEG-Hb with lower oxygen affinity. The PEG chains engineered on Lys as well as PEGylation of Cys-93(β) independently contribute to the stabilization of oxy conformation of Hb and hence increase the oxygen affinity of Hb. However, oxygen affinity of the EAF-PEG-αα-Hb is more sensitive to the presence of PEGylation on Cys-93(β) than that of the EAF-PEG-Hb. The present modified EAF PEGylation platform is expected to facilitate the design of novel versions of the EAF-PEG-Hbs that can now integrate the advantages of avoiding PEGylation of Cys-93(β).

UR - http://www.scopus.com/inward/record.url?scp=71249139373&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=71249139373&partnerID=8YFLogxK

U2 - 10.1021/bc900170e

DO - 10.1021/bc900170e

M3 - Article

VL - 20

SP - 2062

EP - 2070

JO - Bioconjugate Chemistry

JF - Bioconjugate Chemistry

SN - 1043-1802

IS - 11

ER -