12RM

Structure of turkey hemoglobin A at 1.7 Angstrom resolution (tetragonal form)

Summary for 12RM

• Entry DOI: 10.2210/pdb12rm/pdb
• Descriptor: Hemoglobin subunit alpha-A, Hemoglobin beta chain, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: caffeic acid, anti-oxidant, oxygen transport
• Biological source: Meleagris gallopavo (turkey); More
• Total number of polymer chains: 2
• Total formula weight: 32522.06

Authors

Bingman, C.A.,Yin, J.,Smith, R.W.,Richards, M.P. (deposition date: 2026-04-15, release date: 2026-06-17)

Primary citation

Yin, J.,Zhang, W.,Tatiyaborworntham, N.,Bingman, C.A.,Richards, M.P.
Oxidative Characteristics of Turkey Hemoglobin A Containing Covalently Bound Epigallocatechin Gallate.
J.Agric.Food Chem., 2026

PubMed Abstract: We investigated the binding of epigallocatechin gallate (EGCG) to turkey hemoglobin A (Hb), noting that polyphenols have the capacity to inhibit oxidative deterioration in muscle foods mediated by endogenous hemoglobin. The addition of EGCG to MetHb resulted in covalently bound EGCG to Cys of both α-chains. The crystal structure showed that each bound EGCG was located near the other and in the protein interior. Distances between the nearest phenol/phenolate of bound EGCG and the nearest iron atom of the heme moieties were 11.7-16.5 Å. Antioxidative characteristics due to bound EGCG included decreases in both hemin dissociation and HO-mediated ferryl Hb formation, counterbalanced by increased Hb autoxidation. Bound EGCG less effectively inhibited oxyHb-mediated lipid oxidation compared to MetHb-mediated lipid oxidation. The mechanisms by which EGCG adduction affected oxidative characteristics of Hb are discussed, including electron transfer from bound EGCG to the heme, interactions with lipids, and effects of cross-linking on hemin affinity.

PubMed: 42262311
DOI: 10.1021/acs.jafc.5c17482

Experimental method

X-RAY DIFFRACTION (1.695 Å)