1mcy

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spinqualitylabelsall models 1mcy, resolution 1.7Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

SPERM WHALE MYOGLOBIN (MUTANT WITH INITIATOR MET AND WITH HIS 64 REPLACED BY GLN, LEU 29 REPLACED BY PHE

Overview

The functional, spectral, and structural properties of elephant myoglobin, and the L29F/H64Q mutant of sperm whale myoglobin have been compared in, detail by conventional kinetic techniques, infrared and resonance Raman, spectroscopy, 1H NMR, and x-ray crystallography. There is a striking, correspondence between the properties of the naturally occurring elephant, protein and those of the sperm whale double mutant, both of which are, quite distinct from those of native sperm whale myoglobin and the single, H64Q mutant. These results and the recent crystal structure determination, by Bisig et al. (Bisig, D. A., Di Iorio, E. E., Diederichs, K., Winterhalter, K. H., and Piontek, K. (1995) J. Biol. Chem. 270, 20754-20762) confirm that a Phe residue is present at position 29 (B10) in, elephant myoglobin, and not a Leu residue as is reported in the published, amino acid sequence. The single Gln64(E7) substitution lowers oxygen, affinity approximately 5-fold and increases the rate of autooxidation, 3-fold. These unfavorable effects are reversed by the Phe29(B10), replacement in both elephant myoglobin and the sperm whale double mutant., The latter, genetically engineered protein was originally constructed to, be a blood substitute prototype with moderately low O2 affinity, large, rate constants, and increased resistance to autooxidation. Thus, the same, distal pocket combination that we designed rationally on the basis of, proposed mechanisms for ligand binding and autooxidation is also found in, nature.

About this Structure

1MCY is a Single protein structure of sequence from Physeter catodon with SO4, HEM and CMO as ligands. Full crystallographic information is available from OCA.

Reference

A double mutant of sperm whale myoglobin mimics the structure and function of elephant myoglobin., Zhao X, Vyas K, Nguyen BD, Rajarathnam K, La Mar GN, Li T, Phillips GN Jr, Eich RF, Olson JS, Ling J, et al., J Biol Chem. 1995 Sep 1;270(35):20763-74. PMID:7657659

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