Globin, extracellular | |
---|---|
Identifiers | |
Symbol | Haemoglobin_extracell |
InterPro | IPR014610 |
Annelid erythrocruorin linker subunit, C-terminal | |||||||||
---|---|---|---|---|---|---|---|---|---|
Identifiers | |||||||||
Symbol | Eryth_link_C | ||||||||
Pfam | PF16915 | ||||||||
InterPro | IPR031639 | ||||||||
CATH | 2gtlM02 | ||||||||
SCOP2 | 8029676 / SCOPe / SUPFAM | ||||||||
CDD | cd11673 | ||||||||
|
Erythrocruorin (from Greek eruthros "red" + Latin cruor "blood"), and the similar chlorocruorin (from Greek khlōros "green" + Latin cruor "blood"), are large oxygen-carrying hemeprotein complexes, which have a molecular mass greater than 3.5 million daltons. [1] Both are sometimes called giant hemoglobin or hexagonal bilayer haemoglobin. They are found in many annelids and arthropods (including some insects). [2]
Chlorocruorin is particularly found in certain marine polychaetes. [3] [4] [5]
Two structures of erythrocruorin have been resolved. The protein is a highly symmetric assembly made from heme-binding globins and unique linker proteins. [1] [6]
The only significant difference between chlorocruorin and erythrocruorin is that chlorocruorin carries an abnormal heme group structure. Both contain many 16–17 kDa myoglobin-like subunits arranged in a giant complex of over a hundred subunits with interlinking proteins as well with a total weight exceeding 3600 kDa. [6]
Giant hemoglobin is composed of multiple heme-containing globin chains and linker ( InterPro: IPR031639) chains. Each species have different amounts of genes for these chains. For example, while a Lamellibrachia sp. has four kinds of globin chains and two kinds of linker chains, Sabella spallanzanii has three globin chains and three linker chains. [6] The exact stoichiometric ratios and arrangement is unknown, but is thought to resemble that of erythocrorins.
Erythrocruorin has a weaker affinity for oxygen than that of most hemoglobins. A dichromatic compound, chlorocruorin is noted for appearing green in dilute solutions, though it appears light red when found in concentrated solutions. [7] [8] [9]
This enormous macromolecule is typically found free floating in the plasma, and not contained within red blood cells. [6] [10]
Globin, extracellular | |
---|---|
Identifiers | |
Symbol | Haemoglobin_extracell |
InterPro | IPR014610 |
Annelid erythrocruorin linker subunit, C-terminal | |||||||||
---|---|---|---|---|---|---|---|---|---|
Identifiers | |||||||||
Symbol | Eryth_link_C | ||||||||
Pfam | PF16915 | ||||||||
InterPro | IPR031639 | ||||||||
CATH | 2gtlM02 | ||||||||
SCOP2 | 8029676 / SCOPe / SUPFAM | ||||||||
CDD | cd11673 | ||||||||
|
Erythrocruorin (from Greek eruthros "red" + Latin cruor "blood"), and the similar chlorocruorin (from Greek khlōros "green" + Latin cruor "blood"), are large oxygen-carrying hemeprotein complexes, which have a molecular mass greater than 3.5 million daltons. [1] Both are sometimes called giant hemoglobin or hexagonal bilayer haemoglobin. They are found in many annelids and arthropods (including some insects). [2]
Chlorocruorin is particularly found in certain marine polychaetes. [3] [4] [5]
Two structures of erythrocruorin have been resolved. The protein is a highly symmetric assembly made from heme-binding globins and unique linker proteins. [1] [6]
The only significant difference between chlorocruorin and erythrocruorin is that chlorocruorin carries an abnormal heme group structure. Both contain many 16–17 kDa myoglobin-like subunits arranged in a giant complex of over a hundred subunits with interlinking proteins as well with a total weight exceeding 3600 kDa. [6]
Giant hemoglobin is composed of multiple heme-containing globin chains and linker ( InterPro: IPR031639) chains. Each species have different amounts of genes for these chains. For example, while a Lamellibrachia sp. has four kinds of globin chains and two kinds of linker chains, Sabella spallanzanii has three globin chains and three linker chains. [6] The exact stoichiometric ratios and arrangement is unknown, but is thought to resemble that of erythocrorins.
Erythrocruorin has a weaker affinity for oxygen than that of most hemoglobins. A dichromatic compound, chlorocruorin is noted for appearing green in dilute solutions, though it appears light red when found in concentrated solutions. [7] [8] [9]
This enormous macromolecule is typically found free floating in the plasma, and not contained within red blood cells. [6] [10]