title: Structure of hemoglobins Zürich [His E7(63)beta replaced by Arg] and Sydney [Val E11(67)beta replaced by Ala] and role of the distal residues in ligand binding.
abstract: In hemoglobin Zürich the side chain of the distal arginine attaches itself to the propionate of the heme, leaving the heme pocket wide open, allowing sulfanilamides easy access to the iron, and doubling the partition coefficient between CO and O2. The replacement of the distal valine by alanine in hemoglobin Sydney leaves a large gap inside the heme pocket, which is partly filled by a water molecule bonded to the distal histidine. Hemoglobin Sydney has the same partition coefficient between CO and O2 as hemoglobin A. Replacement of the distal histidine increases the stretching frequency of CO linked to the beta heme by 6 cm-1, but replacement of the distal valine increases it by only 3 cm-1, but replacement of the distal histidine leaves the O-O stretching frequency unchanged.
mesh_terms: D000409:Alanine; D000595:Amino Acid Sequence; D001120:Arginine; D001665:Binding Sites; D006455:Hemoglobins, Abnormal; D006639:Histidine; D006801:Humans; D008024:Ligands; D010100:Oxygen; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D014633:Valine; D014961:X-Ray Diffraction
chemical_list: D006455:Hemoglobins, Abnormal; D008024:Ligands; D006639:Histidine; D001120:Arginine; D014633:Valine; D000409:Alanine; D010100:Oxygen
references.citation: Blood. 1962 Sep;20:261-71
references.pmid: 13895148
references.citation: Biochim Biophys Acta. 1961 Jul 8;50:595
references.pmid: 13726693
references.citation: Helv Paediatr Acta. 1960 Dec;15:499-514
references.pmid: 13714685
references.citation: Nature. 1951 Jun 9;167(4258):929-31
references.pmid: 14843112
references.citation: J Mol Biol. 1977 Aug 15;114(3):415-20
references.pmid: 20512
references.citation: J Biol Chem. 1977 Jul 25;252(14):4882-7
references.pmid: 17607
references.citation: J Mol Biol. 1977 Aug 15;114(3):385-414
references.pmid: 561852
references.citation: Br J Haematol. 1978 Feb;38(2):195-209
references.pmid: 638069
references.citation: Eur J Biochem. 1977 May 2;75(1):267-73
references.pmid: 862620
references.citation: J Phys E. 1977 Apr;10(4):351-8
references.pmid: 859118
references.citation: J Mol Biol. 1977 Mar 5;110(3):569-84
references.pmid: 845960
references.citation: Proc Natl Acad Sci U S A. 1976 Oct;73(10):3333-7
references.pmid: 1068445
references.citation: J Mol Biol. 1976 Jan 5;100(1):3-11
references.pmid: 1249840
references.citation: Biochemistry. 1972 Apr 25;11(9):1677-81
references.pmid: 5063711
references.citation: Biochemistry. 1974 May 7;13(10):2163-73
references.pmid: 4826890
references.citation: Biochem Biophys Res Commun. 1970 Jul 27;40(2):343-9
references.pmid: 5482264
references.citation: Nature. 1967 Aug 5;215(5101):626-8
references.pmid: 6050213
references.citation: Nature. 1970 Nov 21;228(5273):726-39
references.pmid: 5528785
references.citation: Proc R Soc Lond B Biol Sci. 1969 May 20;173(1031):113-40
references.pmid: 4389425
references.citation: Ann N Y Acad Sci. 1970 Oct 5;174(1):148-53
references.pmid: 4332406
references.citation: Cold Spring Harb Symp Quant Biol. 1972;36:295-310
references.pmid: 4508142
references.citation: J Mol Biol. 1973 Sep 25;79(3):495-506
references.pmid: 4796594
references.citation: Proc Natl Acad Sci U S A. 1970 Oct;67(2):485-92
references.pmid: 5289003
references.citation: J Mol Biol. 1976 Jul 5;104(3):707-22
references.pmid: 950675
references.citation: Biochem Biophys Res Commun. 1976 Feb 23;68(4):1379-86
references.pmid: 1267786
references.citation: J Mol Biol. 1975 Sep 15;97(2):237-56
references.pmid: 1177322
references.citation: Biochem Biophys Res Commun. 1975 Feb 3;62(3):561-7
references.pmid: 1120068
references.citation: Proc Natl Acad Sci U S A. 1970 Mar;65(3):697-701
references.pmid: 5267148
references.citation: Nature. 1970 Nov 7;228(5271):551-2
references.pmid: 5472471
references.citation: Eur J Biochem. 1969 Dec;11(3):435-40
references.pmid: 5368335
references.citation: J Mol Biol. 1968 Oct 14;37(1):225-30
references.pmid: 5760491
references.citation: Nature. 1968 Aug 31;219(5157):902-9
references.pmid: 5691676