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1.
The blood of the Electric Ray contains a number of hemoglobin components. The primary structures of the alpha- and beta-chains of the main components are presented. These chains were purified by high-performance liquid chromatography, using a new buffer system. The alpha-chains consist of 141 residues, and the beta-chains of 142 residues; both are unblocked. The phylogenetic distances from human alpha- and beta-chains are 55% and 64% amino-acid exchanges, respectively. The relationship between primary structure and the lack of both a Bohr effect and any effector affinity is discussed, and interpreted on a molecular level with reference to the sequence presented. For the Bohr effect, the mutation beta 89 Asp----Lys is significant, while the mutations beta 2 His----Ser, beta 82 Lys----Asn and beta 142 His----Cys are important for the lack of effector affinity.  相似文献   

2.
The amino-acid sequence of the hemoglobin of the Dogfish Shark (Squalus acanthias) is presented. The alpha-chains consist of 141 residues and show a Thr/Ser ambiguity at position 3. The beta-chains consist of 142 residues and evidently have no D-helix; they show an Asn/Tyr ambiguity at position 104. Both chains have free N-terminal amino acids. The phylogenetic distance from the human alpha- and beta-chains is indicated by 49.3% and 56.2% amino-acid exchanges. The primary structure is discussed in relation to the oxygen-binding properties of elasmobranch hemoglobin, particularly as regards the antagonistic effects of urea and ATP, and the effects of proton concentration (the alkaline and acid Bohr effects, and the Root effect).  相似文献   

3.
The coelacanth (Latimeria chalumnae, Actinistia) has a single hemoglobin component. The primary structures of the alpha- and beta-chains are presented. They could be separated by reversed-phase HPLC. Peptides obtained by tryptic digestion of the native and oxidized chains were isolated by reversed-phase HPLC and sequenced in liquid and gas-phase sequenators. The alignment was achieved by employing the N-terminal sequences of the native chains and those of a beta-chain cyanogen bromide peptide as well as fragments obtained by acid hydrolysis. The Latimeria alpha-chains consist of 142 amino-acid residues, due to a fish-specific insertion between positions 46 and 47, whereas the beta-chains are of normal length (146 residues). Latimeria alpha- and beta-chains share 72 (51.1%) and 70 (47.9%) identical residues with human hemoglobin, respectively. Numerous heme contacts and positions involved in subunit interface contacts are replaced. The most interesting of them were studied by molecular modeling. The loss of an alpha 1/beta 2-contact by the exchanges alpha 92(FG4)Arg----Leu and beta 43(CD2)Glu----Lys might be responsible for the easy dissociation of the tetrameric hemoglobin molecule. A comparison of the residues replaced in contact positions with fishes and amphibians revealed the highest number of matches between Latimeria and tadpoles. The same result was obtained by the evaluation of other regions relevant for structure and function of the molecule, like exon-intron boundary regions, phosphate binding sites and salt bridges responsible for the Bohr effect.  相似文献   

4.
The primary structure of the alpha- and beta-chains of hemoglobin from the Masked Palm Civet (Paguma larvata, Viverridae) is described. The chains were separated directly from hemoglobin by RP-HPLC. After tryptic digestion of the chains, the peptides were separated by RP-HPLC. Amino acid sequences were determined by Edman degradation in liquid and gas-phase sequencers. The alignment of the tryptic peptides was made by homology with human and other Carnivora hemoglobins. Paguma and human hemoglobin differ with respect to 23 amino-acid residues. Some of these amino-acid substitutions, which occur in both the alpha- and beta-chains, occur at contact sites between the subunits, and at the binding sites of heme and of organic phosphate, as well as involving residues responsible for the alkaline Bohr effect.  相似文献   

5.
The hemoglobin of the Common Otter (Lutra lutra, Carnivora) contains only one component. The complete primary structures of the alpha- and beta-chains are presented. They were separated by high-performance liquid chromatography and the sequences determined by automatic liquid and gas-phase Edman degradation of the chains and their tryptic peptides. The alpha-chains show 18 and the beta-chains 13 substitutions compared to human alpha- and beta-chains, respectively. In the alpha-chains one heme- and two alpha 1/beta 1-contacts are exchanged. In the beta-chains the replacements involve one heme-, one alpha 1/beta 1-, and one alpha 1/beta 2-contact. The alpha- and beta-chains of the Common Otter are compared to those of other Carnivora hemoglobins. The unexpected low number of substitutions between Common Otter hemoglobin and that of Lesser Panda as well as of Harbor Seal is discussed.  相似文献   

6.
The hemoglobin of the European marmot Marmota marmota marmota has been found to consist of only one component. In this work, we are presenting its primary structure. The globin chains have been separated by high performance liquid chromatography and the sequences have been determined by automated Edman degradation of the chains and their tryptic peptides, as well as of the peptide obtained by acid hydrolysis of the Asp-Pro bond in the beta-chains. In the alpha-chains we have found 13 and in the beta-chains 34 exchanges compared with the human alpha- and beta-chains, respectively. The amino acids which are substituted in the alpha-chains are not involved in any contacts, whereas in the beta-chains, one exchange involves a heme contact, two alpha 1/beta 1- and one alpha 1/beta 2-contacts. The functional and evolutionary aspects of these findings are discussed.  相似文献   

7.
The complete primary structure of the hemoglobin from the Pallid Bat (Antrozous pallidus, Microchiroptera) is presented. This hemoglobin consists of two components with identical amino-acid sequences, differing, however, in the N-terminus which is formylated in 12.5% of the beta-chains. The alpha- and beta-chains were separated by reversed phase high performance liquid chromatography. The sequences of both chains were established by automatic Edman degradation with the film technique or gas phase method using the native chains and the tryptic peptides. The formylation of a part of the N-terminal peptide of the beta-chains was determined by mass spectrometric examination. Compared to the corresponding human chains we found 14 substitutions in the alpha-chains and 21 in the beta-chains. One substitution in the alpha-chains and three in the beta-chains are involved in alpha 1/beta 1-contacts. Among these the exchange beta 123(H1)Thr----Cys is unusual because cysteine was so far not found in this position of mammalian beta-chains. Compared to the hemoglobin of Myotis velifer, another representative of the family Vespertilionidae, 5 residues are replaced in the alpha-chains and 18 in the beta-chains.  相似文献   

8.
The complete primary structure of the hemoglobin from the bat Macrotus californicus (Chiroptera) is presented. This hemoglobin consists of only one component. The alpha- and beta-chains were separated by reverse phase high performance liquid chromatography. The sequences of both chains were established by automatic Edman degradation of the chains and the tryptic peptides, as well as of the C-terminal peptide obtained by acidic hydrolysis of the Asp-Pro bond in the beta-chains using the film- and gas-phase method. The sequences are compared with human hemoglobin: 15 amino-acid substitutions are found in the alpha- and 22 in the beta-chains. A comparison with the hemoglobin of Rousettus aegyptiacus and Myotis velifer shows a closer relation to the Mega- than to the Microchiroptera.  相似文献   

9.
The primary structures of alpha- and beta-chains from the hemoglobin of the Beach Marten (Martes foina, Carnivora) are presented. The globin chains were separated on CM-cellulose in 8M urea buffer. The amino-acid sequences were established by automatic liquid- and gas-phase Edman degradation of the intact chains and the tryptic peptides from oxidized chains. Comparison of the sequences with human hemoglobin shows 21 exchanges in the alpha- and 12 in the beta-chains. The differences concerning heme and interchain contact sites as well as the substitution alpha 77 (EF6)Pro----Ala are discussed. The latter is observed for the first time in a mammalian hemoglobin. The sequences are compared with those of other Carnivora. The beta-chains of Martes foina and Pteronura brasiliensis (Giant Otter) are found to be identical, but their alpha-chains differ in 7 positions. The surprising small numbers of exchanges between the hemoglobin from Beach marten and that from Lesser and Greater Panda are discussed.  相似文献   

10.
The amino-acid sequences of the alpha- and beta-chains of gayal hemoglobin have been determined and compared with those of bovine and yak hemoglobins. The gayal alpha-chain differs from the alpha-chains of bovine by 3 amino-acid residues and from yak I alpha- and II alpha-hemoglobins by 4 and 2 residues, respectively. The gayal beta-chain differs from bovine beta A- and beta B-chains by 3 and 4 residues, respectively and from yak beta-chains by 2 residues.  相似文献   

11.
Mole rat (Spalax ehrenbergi) hemoglobin consists of only one component. The complete amino-acid sequence of the alpha- and beta-chains of the species with the diploid chromosome number of 60 is presented. Following chain separation by chromatography on carboxymethyl cellulose CM-52, the primary structures were established by automatic Edman degradation on the chains, on the tryptic peptides, and on a peptide obtained by acid hydrolysis of the Asp-Pro bond in beta-chains. The alignment of the peptides was performed by homology with human alpha- and beta-chains. The comparison showed an exchange of 23 residues in the alpha-chains and 26 in the beta-chains. One substitution in the beta-chains concerns the surrounding of the heme. We found two exchanges in each chain in the alpha 1 beta 1-subunit interface and one in the beta-chain alpha 1 beta 2-contact points. Though all binding sites for 2,3-bisphosphoglycerate are unchanged, the mole rat blood has a high oxygen affinity as a part of adaptation to subterranean life under hypoxia and hypercapnia. A comparison of the sequence with known X-ray models of hemoglobins may give an interpretation of this fact. The primary structure of the mole rat hemoglobin shows more similarities with surface rodents, than with the mole, another small mammal, adapted to hypoxia in subterranean tunnels. The adaptation to hypoxia in mole rat and mole must be due to different mechanisms.  相似文献   

12.
The hemoglobin of the Giant Otter (Pteronura brasiliensis, Carnivora) contains only one component. The complete primary structures of the alpha- and beta-chains are presented. The globin chains were separated by high-performance liquid chromatography and the sequences determined by automatic liquid- and gas-phase Edman degradation of the chains and their tryptic peptides. The alpha-chains show 18 and the beta-chains 12 exchanges compared with human alpha- and beta-chains, respectively. In the alpha-chains, two substitutions involve alpha 1/beta 1-contacts and one a heme-contact. In the beta-chains one alpha 1/beta 1-, one alpha 1/beta 2- and one heme-contact are exchanged. The alpha- and beta-chains of the Giant Otter are compared to those of the Common Otter and other Carnivora hemoglobins.  相似文献   

13.
The primary structures of the alpha- and beta-chains of hemoglobin from the Northern Elk (Alces alces alces) have been determined. The sequence was compared with the bovine chains. The oxygen affinity regarding the primary structure of the beta-chains is discussed.  相似文献   

14.
The primary structure of the alpha- and beta-chains of hemoglobin from spotted hyena (Crocuta crocuta, Hyenidae) is presented. The structure-function relationship is discussed. The separation of the chains directly from hemoglobin was performed by RP-HPLC. After tryptic digestion of the chains, the peptides were isolated by RP-HPLC. Amino-acid sequences were determined by Edman degradation in liquid- and gas-phase sequencers. The alignment of the tryptic peptides was made by homology with human and other Carnivora hemoglobins. The hemoglobin from spotted hyena (Crocuta crocuta) exhibits in its alpha- and beta-chains 22 and 20 exchanges, respectively, compared to human hemoglobin. In the alpha-chains, two alpha 1 beta 1-contacts are exchanged. In the beta-chains five exchanges involve one alpha 1 beta 1-contact, one alpha 1 beta 2-contact, one heme contact, and two 2,3-DPG-binding sites.  相似文献   

15.
The primary structure determination of the hemoglobin alpha- and beta-chains from the silver fox (Vulpes vulpes var., Canidae) is described. The separation of the chains could be achieved directly from the hemoglobin by RP-HPLC as well as by column chromatography of the globin using carboxymethyl-cellulose. Following tryptic digestion of the chains, the peptides were isolated by RP-HPLC. Amino-acid sequences were determined by Edman degradation in liquid and gas phase sequencers. The peptides could be aligned by homology with human and other Carnivora hemoglobins. Compared to human hemoglobin the alpha- and beta-chains of the silver fox exhibit 24 and 13 amino-acid exchanges, respectively. They differ by one alpha- and two beta-chain replacements from the domestic dog and the coyote. The substitutions affecting contact positions are discussed.  相似文献   

16.
The primary structures of the alpha- and beta-chains from greylag goose (Anser anser) hemoglobin are given. The sequence was deduced automatically in the sequenator. They differ from chicken alpha-chains in the exchange of 30, from beta-chains in the exchange of only 8 amino acid residues, respectively. The contact points of inositol pentaphosphate with the beta-chains are identical in chicken and greylag goose. Unequal evolution of the beta-chains was found, which is published here for the first time. By comparing the sequences of chicken and greylag goose and considering paleontological data, we found the mutation rate of the alpha-chains to be normal, i.e. 6 million years/mutation. This corresponds to the values for other species. The mutation rate of beta-chains is reduced and was calculated at 25 million years/mutation. This is possibly due to a specific function of beta-chains. This paper is the basis of our attempt to explain on a molecular basis the ability of bar-headed goose (Anser indicus) to fly and breathe at high altitudes.  相似文献   

17.
The hemoglobin of the Mouse-Eared Bat Myotis velifer consists of one component. We present the primary structures of the alpha- and beta-globin chains which have been separated by chromatography on carboxymethyl-cellulose CM-52. The sequences have been determined by Edman-degradation with the film technic or the gas phase method, using the native chains and the tryptic peptides, as well as the C-terminal prolyl-peptides obtained by acid hydrolysis of the Asp-Pro-bonds. Compared to the corresponding human chains we found only 13 substitutions in the alpha-chains, but 27 in the beta-chains. The amino-acid residues substituted in the alpha-chains are not involved in any contacts, whereas in the beta-chains, one exchange involves a heme contact, three alpha 1/beta 1- and one alpha 1/beta 2-contacts, the latter [beta 43(CD2)-Glu----Thr] brings for the first time threonine in this position of the beta-chains. Comparison with the Egyptian Fruit Bat (Rousettus aegyptiacus) shows 12 and 25 substitutions in the alpha- and beta-chains, respectively, suggesting a large phylogenetic distance between Micro- and Megachiroptera. We consider this primary structure as a contribution towards solving the problem of the origin of bats and their relation to primates.  相似文献   

18.
The hemoglobin of the Indian false vampire Megaderma lyra contains only one component. In this paper, we are presenting its primary structure. The globin chains were separated by high-performance liquid chromatography and the sequences determined by automatic liquid and gas phase Edman degradation of the chains and their tryptic peptides, as well as of the prolyl-peptides obtained by acid hydrolysis of the Asp-Pro bond in the alpha- and beta-chains. The alpha-chains show 23 and the beta-chains 20 exchanges compared with the human alpha- and beta-chains, respectively. In the alpha-chains, three exchanges involved alpha 1/beta 1 contacts. In the beta-chains one heme-and three alpha 1/beta 1 contacts are exchanged. The functional and systematic aspects of these replacements are discussed.  相似文献   

19.
The primary structure of the alpha- and beta-chains of the hemoglobin from the Pacific Walrus (Odobenus rosmarus divergens, Pinnipedia) is presented. Sequence analysis revealed only one hemoglobin component whereas two bands were found in polyacrylamide gel electrophoresis. The globin chains were separated by high-performance liquid chromatography and the sequences determined by automatic liquid- and gas-phase sequencing of the chains and their tryptic peptides. The alpha-chains show 20 and the beta-chains 12 exchanges compared to the corresponding human chains. In the alpha-chains one heme- and two alpha 1/beta 1-contacts were exchanged whereas in the beta-chains one alpha 1/beta 1-, one alpha 1/beta 2-and one heme-contact are substituted. Compared to Harbour Seal (Phoca vitulina) the Walrus hemoglobin shows 9 amino-acid replacements in the alpha-chains and 5 in the beta-chains. The relation between Pinnipedia and Arctoidea is discussed.  相似文献   

20.
The hemoglobin of the Brazilian Manatee (Trichechus inunguis, Sirenia) consists of one component. We present the primary structures of the alpha- and beta-chains which have been separated by chromatography on carboxymethyl-cellulose CM-52. The sequences have been determined by automatic Edman degradation with the film technique, using the native chains, tryptic peptides and the C-terminal prolyl-peptide obtained by acid hydrolysis of the Asp-Pro bond of the alpha-chains. Compared to the corresponding human chains we found 27 substitutions in the alpha- as well as in the beta-chains. Three heme contacts and four alpha 1/beta 1 contacts between the subunits are affected by exchanges. The hemoglobin of Trichechus inunguis is compared with those of Elephas maximus, Loxodonta africana, and Procavia habessinica and the monophyletic origin of the superorder Paenungulata is discussed.  相似文献   

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