Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme
The crystal structures of sperm whale metmyoglobins reconstituted with three kinds of modified hemes, 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyldeuteroheme, and 2-vinyl-4-isopropyldeuteroheme, have been determined and refined at 2.2 Å resolution to R = 0.216, 0.219, and 0.195, respectively. All...
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Oxford University Press
1986
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fthighwire:oai:open-archive.highwire.org:jbiochem:100/2/277 2023-05-15T18:26:49+02:00 Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme MIKI, Kunio HARADA, Shigeharu HATO, Yukinori IBA, Seigo KAI, Yasushi KASAI, Nobutami KATSUBE, Yukiteru KAWABE, Kuniyasu YOSHIDA, Zen-ichi OGOSHI, Hisanobu 1986-01-01 00:00:00.0 text/html http://jb.oxfordjournals.org/cgi/content/short/100/2/277 en eng Oxford University Press http://jb.oxfordjournals.org/cgi/content/short/100/2/277 Copyright (C) 1986, Japanese Biochemical Society REGULAR PAPERS TEXT 1986 fthighwire 2013-05-27T14:04:22Z The crystal structures of sperm whale metmyoglobins reconstituted with three kinds of modified hemes, 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyldeuteroheme, and 2-vinyl-4-isopropyldeuteroheme, have been determined and refined at 2.2 Å resolution to R = 0.216, 0.219, and 0.195, respectively. All the crystals of these myoglobins are isomorphous with that of native metmyoglobin. The 2-vinyl-4-isopropyldeuteroheme was found to be in a reverse orientation, in which the heme plane is rotated by 180° about an axis through the α-γ-meso carbons, whereas the orientations of the other two hemes were the same as that of protoheme in native myoglobin. In the myoglobins with 2,4-diisopropyldeuteroheme and 2-vinyl-4-isopropyldeuteroheme, both of which have lower oxygen affinities than native myoglobin, the bulky isopropyl side chain pushes Phe 43 0.7 Å toward His 64 (the distal histidine) in the former, and the whole E helix at most 1.5 Å, including a 0.7 Å shift of the His 64 imidazole ring, in the latter. The changes of the structures prevent His 64 from forming a hydrogen bond with the liganded oxygen molecule, so that these two modified myoglobins show low oxygen affinities. On the other hand, there is no such drastic displacement in myoglobin with 2-isopropyl-4-vinyldeutero-heme, which has a slightly higher oxygen affinity than native myoglobin. Text Sperm whale HighWire Press (Stanford University) |
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HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
REGULAR PAPERS |
spellingShingle |
REGULAR PAPERS MIKI, Kunio HARADA, Shigeharu HATO, Yukinori IBA, Seigo KAI, Yasushi KASAI, Nobutami KATSUBE, Yukiteru KAWABE, Kuniyasu YOSHIDA, Zen-ichi OGOSHI, Hisanobu Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
topic_facet |
REGULAR PAPERS |
description |
The crystal structures of sperm whale metmyoglobins reconstituted with three kinds of modified hemes, 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyldeuteroheme, and 2-vinyl-4-isopropyldeuteroheme, have been determined and refined at 2.2 Å resolution to R = 0.216, 0.219, and 0.195, respectively. All the crystals of these myoglobins are isomorphous with that of native metmyoglobin. The 2-vinyl-4-isopropyldeuteroheme was found to be in a reverse orientation, in which the heme plane is rotated by 180° about an axis through the α-γ-meso carbons, whereas the orientations of the other two hemes were the same as that of protoheme in native myoglobin. In the myoglobins with 2,4-diisopropyldeuteroheme and 2-vinyl-4-isopropyldeuteroheme, both of which have lower oxygen affinities than native myoglobin, the bulky isopropyl side chain pushes Phe 43 0.7 Å toward His 64 (the distal histidine) in the former, and the whole E helix at most 1.5 Å, including a 0.7 Å shift of the His 64 imidazole ring, in the latter. The changes of the structures prevent His 64 from forming a hydrogen bond with the liganded oxygen molecule, so that these two modified myoglobins show low oxygen affinities. On the other hand, there is no such drastic displacement in myoglobin with 2-isopropyl-4-vinyldeutero-heme, which has a slightly higher oxygen affinity than native myoglobin. |
format |
Text |
author |
MIKI, Kunio HARADA, Shigeharu HATO, Yukinori IBA, Seigo KAI, Yasushi KASAI, Nobutami KATSUBE, Yukiteru KAWABE, Kuniyasu YOSHIDA, Zen-ichi OGOSHI, Hisanobu |
author_facet |
MIKI, Kunio HARADA, Shigeharu HATO, Yukinori IBA, Seigo KAI, Yasushi KASAI, Nobutami KATSUBE, Yukiteru KAWABE, Kuniyasu YOSHIDA, Zen-ichi OGOSHI, Hisanobu |
author_sort |
MIKI, Kunio |
title |
Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
title_short |
Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
title_full |
Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
title_fullStr |
Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
title_full_unstemmed |
Crystal Structures of Modified Myoglobins. II. Relation between Oxygen Affinity Properties and Structural Changes around Heme in Myoglobins Reconstituted with 2,4-Diisopropyldeuteroheme, 2-Isopropyl-4-VinyIdeuteroheme, and 2-Vinyl-4-Isopropyldeuteroheme |
title_sort |
crystal structures of modified myoglobins. ii. relation between oxygen affinity properties and structural changes around heme in myoglobins reconstituted with 2,4-diisopropyldeuteroheme, 2-isopropyl-4-vinyideuteroheme, and 2-vinyl-4-isopropyldeuteroheme |
publisher |
Oxford University Press |
publishDate |
1986 |
url |
http://jb.oxfordjournals.org/cgi/content/short/100/2/277 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
http://jb.oxfordjournals.org/cgi/content/short/100/2/277 |
op_rights |
Copyright (C) 1986, Japanese Biochemical Society |
_version_ |
1766208788057030656 |