Enhanced molecular volume of conservatively pegylated Hb: (SP-PEG5K) 6-HbA is non-hypertensive

Seetharama A. Acharya, Joel M. Friedman, Belur N. Manjula, Marcos Intaglietta, Amy G. Tsai, Robert M. Winslow, Ashok Malavalli, Kim Vandegriff, Paul K. Smith

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Recent studies have suggested that the "pressor effect" of acellular Hb is a consequence of perturbation of the macro-and microcirculatory system in multiple ways, and that PEGylation is an effective approach for controlling the same. In an attempt to confirm this concept, a new and simple thiolation mediated, maleimide chemistry-based conservative PEGylation protocol has been developed to conjugate multiple copies of PEG-chains to Hb. This approach combines the high reactivity of maleimides towards thiols with the propensity of iminothiolane to derivatize the ε-amino groups of proteins into reactive thiol groups, with conservation of their positive charge. One of the PEGylated products, namely (SP-PEGSK)6-HbA, that carries on an average six copies of PEG5000 chains per Hb, is non-hypertensive in hamster top load and in rat 50% exchange transfusion models. This hexa-PEGylated-Hb has (i) a hydrodynamic volume corresponding to that of an oligomerized Hb of 256 kDa, (ii) a molecular radius of ∼6.8 nm, (iii) high oxygen affinity, (iv) lowered Bohr effect, and (v) increased viscosity and colloidal osmotic pressure. These properties of (SP-PEGSK)6-HbA are consistent with the emerging new paradigms for the design of Hb based oxygen carriers and confirm the concept that the "pressor effect" of Hb is a multifactorial event. The thiolation mediated maleimide chemistry-based PEGylation protocol described here for the generation of (SP-PEGSK)6-Hb is simple, highly efficient, and is carried out under oxy conditions. The results demonstrate that a non-hypertensive PEG-Hb can be generated by conjugation of a lower number of PEG chains than previously reported.

Original languageEnglish (US)
Pages (from-to)239-255
Number of pages17
JournalArtificial Cells, Blood Substitutes, and Immobilization Biotechnology
Volume33
Issue number3
DOIs
StatePublished - 2005

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Polyethylene glycols
Sulfhydryl Compounds
Maleimides
Oxygen
Network protocols
Osmotic Pressure
Hydrodynamics
Viscosity
Cricetinae
Macros
Rats
Conservation
Proteins
arginyl-threonyl-prolyl-prolyl-prolyl-seryl-glycine
maleimide
PEG-hemoglobin

ASJC Scopus subject areas

  • Biomedical Engineering
  • Hematology
  • Biotechnology
  • Biomaterials

Cite this

Enhanced molecular volume of conservatively pegylated Hb : (SP-PEG5K) 6-HbA is non-hypertensive. / Acharya, Seetharama A.; Friedman, Joel M.; Manjula, Belur N.; Intaglietta, Marcos; Tsai, Amy G.; Winslow, Robert M.; Malavalli, Ashok; Vandegriff, Kim; Smith, Paul K.

In: Artificial Cells, Blood Substitutes, and Immobilization Biotechnology, Vol. 33, No. 3, 2005, p. 239-255.

Research output: Contribution to journalArticle

Acharya, SA, Friedman, JM, Manjula, BN, Intaglietta, M, Tsai, AG, Winslow, RM, Malavalli, A, Vandegriff, K & Smith, PK 2005, 'Enhanced molecular volume of conservatively pegylated Hb: (SP-PEG5K) 6-HbA is non-hypertensive', Artificial Cells, Blood Substitutes, and Immobilization Biotechnology, vol. 33, no. 3, pp. 239-255. https://doi.org/10.1081/BIO-200066365
Acharya, Seetharama A. ; Friedman, Joel M. ; Manjula, Belur N. ; Intaglietta, Marcos ; Tsai, Amy G. ; Winslow, Robert M. ; Malavalli, Ashok ; Vandegriff, Kim ; Smith, Paul K. / Enhanced molecular volume of conservatively pegylated Hb : (SP-PEG5K) 6-HbA is non-hypertensive. In: Artificial Cells, Blood Substitutes, and Immobilization Biotechnology. 2005 ; Vol. 33, No. 3. pp. 239-255.
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AU - Acharya, Seetharama A.

AU - Friedman, Joel M.

AU - Manjula, Belur N.

AU - Intaglietta, Marcos

AU - Tsai, Amy G.

AU - Winslow, Robert M.

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AU - Vandegriff, Kim

AU - Smith, Paul K.

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