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Biomedical subjects

G Braunitzer

Publications and source records attributed to G Braunitzer.

At least 37 records · Page 2Linked to original sources
PubMed1990

Primary structure and oxygen-binding properties of the hemoglobin from guanaco (Lama guanacoë, Tylopoda).

The primary structure of the hemoglobin from guanaco (Lama guanacoë, Tylopoda) is presented. It could be separated into the chains by CM-cellulose chromatography. The sequences have been determined by automatic Edman degradation with the film technique or gas phase method, using the native chains and the tryptic peptides of the oxidized chains as well as a fragment obtained by acid hydrolysis. Guanaco hemoglobin has identical alpha-chains with alpaca and identical beta-chains with all Lama species with the exception that one guanaco in this study had alanine and serine in the ratio 1:1 in position beta 135 whereas a second individual had alanine only. Since the data suggest that the domesticated species llama and alpaca originate from the guanaco, it seems likely that beta 135Ala is the common form. Guanaco, llama, and alpaca show a comparable high blood oxygen affinity, caused by the substitution beta 2(NA2)His----Asn, as an adaptation to life at high altitude.

Amino Acid Sequence↗
PubMed1989

Carnivora: the primary structure of the Pacific Walrus (Odobenus rosmarus divergens, Pinnipedia) hemoglobin.

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.

Amino Acid Sequence↗
PubMed1989

The primary structure of the hemoglobin of the electric eel (Electrophorus electricus).

The blood of the Electric Eel contains only one hemoglobin component. The primary structures of the alpha- and beta-chains are presented. These were separated by high-performance liquid chromatography, using a new kind of buffer system. The alpha-chains are acetylated, and consist of 142 residues, while the beta-chains are not blocked, and consist of 147 residues. The phylogenetic distances between these and the alpha- and beta-chains of human hemoglobin are 48 and 50% amino-acid exchanges, respectively. The relationship between primary structure and the Bohr effect and Root effect is discussed, especially the significance of the serine found in position F9 beta.

Amino Acid Sequence↗
PubMed1989

Carnivora: the amino-acid sequence of the adult Sumatran tiger (Panthera tigris sumatrae) hemoglobins.

The complete amino-acid sequences of the hemoglobins from the adult Sumatran tiger (Panthera tigris sumatrae) have been determined on automatic liquid- and gas-phase sequenators. The globin chains were isolated by reverse phase HPLC on a column of Nucleosil-C4. N-Acetylserine was detected by FAB-mass spectroscopy as N-terminal aminoacid residue of the beta I chain. Comparing the sequences of the globin chains of the tiger with that of human Hb-A, 23 substitutions were recognized in the alpha, 29 in beta I and 28 in the beta II chain.

Amino Acid Sequence↗
PubMed1989

The primary structure of pale-throated three-toed sloth (Bradypus tridactylus, Xenarthra) hemoglobin.

The hemoglobin of the Pale-Throated Three-Toed Sloth (Bradypus tridactylus, Xenarthra) was separated into two components (ratio 4:1) with identical amino-acid analyses for the alpha- and beta-chains. The primary structures of both chains from the major component are given. They could be isolated by chromatography on carboxymethyl cellulose CM-52. The sequences have been determined by automatic Edman degradation of the native chains and their tryptic peptides. The comparison with human hemoglobin showed 27 substitutions in the alpha-chains and 33 in the beta-chains. In the alpha-chains one amino-acid exchange involves an alpha 1/beta 1-contact. In the beta-chains two heme- and four alpha 1/beta 1-contacts are substituted. The hemoglobin of the Sloth is compared to that of the Nine-Banded Armadillo (Dasypus novemcinctus), another representative of the order Xenerthra.

Amino Acid Sequence↗
PubMed1989

The hemoglobins of the adult blackbird (Turdus merula, Passeriformes). The sequence of the major (HbA) and minor component (HbD).

The blood of the adult blackbird contains one major hemoglobin component (HbA = alpha A2, beta 2, ca. 80%) and one minor one (HbD = alpha D2 beta 2, ca. 20%). The Hb-components were separated by FPLC on a TSK SP-5 PW column, and eluted with a linear NaCl gradient, while the globin chains were purified on a cation exchange (CM-Cellulose). Tryptic peptides from the globin chains were separated by HPLC on an RP-2 Lichrosorb column. The complete amino acid sequence was determined by automatic Edman degradation, using film and gas phase methods. For the alpha A-, alpha D- and beta-chains, peptide alignment was carried out relative to the corresponding chains of the greylag goose (Anser anser). The close phylogenetic relationship between blackbird, tree sparrow and starling is verified by the hemoglobin sequence. The O2-affinities of the major and minor hemoglobin components of the blackbird are not yet known. Thus, the results were interpreted on the basis of primary structure. Substitutions of possible structural significance were examined with the help of molecular graphics/modelling.

Amino Acid Sequence↗
PubMed1989

Carnivora: the primary structure of the giant otter (Pteronura brasiliensis, Mustelidae) hemoglobin.

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.

Amino Acid Sequence↗
PubMed1989

Carnivora: primary structure of the hemoglobin from the spotted hyena (Crocuta crocuta, Hyenidae).

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.

Amino Acid Sequence↗
PubMed1989

The thiol proteinases from the latex of Carica papaya L. III. The primary structure of chymopapain.

The amino-acid sequence of chymopapain is presented. It was isolated from the latex of the fruits from the tropical species Carica papaya L. and is, besides papain and papaya proteinase omega, the third thiol proteinase from this source. The primary structure contains 218 amino-acid residues. It was deduced from sequence analysis of the native enzyme and of peptides obtained by tryptic, chymotryptic, peptic, thermolysinolytic and mild acidic hydrolysis. Out of a total of eight cysteine residues, six are involved in the formation of three disulfide bonds, the location of which has been established with the help of peptic and thermolysinolytic peptides and fragments, obtained by mild acidic hydrolysis. Chymopapain shares 126 identical amino-acid residues (58%) with papain and 141 (65%) with papaya proteinase omega, including the three disulfide bridges and the free cysteine in position 25, required for activity. Except some amino-acid residues in the substrate-binding site, all residues involved in the catalytic mechanism are conserved. The homology between papaya proteinases is discussed.

Amino Acid Sequence↗
PubMed1989

Carnivora: the primary structure of the alpha-chains of ferret (Mustela putorius furo, Mustelidae) hemoglobins.

Ferret erythrocytes contain two hemoglobins differing only by their alpha-chains. The primary structure of the common beta-chain has been previously described; the complete sequence of the two alpha-chains are reported in this paper. The globin chains were separated by ion-exchange chromatography; the alpha-chains (42 steps), their tryptic peptides as well as the prolyl-peptides were subjected to automatic liquid- and gas-phase Edman degradation. The two alpha-chains are very similar, differing at only one position (Asp15----Gly15). Comparison with human hemoglobin alpha-chain shows 16 and 17 exchanges, for alpha 1 and alpha II chains, respectively; two substitutions involve alpha 1/beta 1 contacts and one the heme contacts. A high degree of homology was noted when the alpha-chains were compared to the corresponding chains of other representatives of the Carnivora order.

Amino Acid Sequence↗
PubMed1989

Amino-acid sequences and functional differentiation of hemoglobins A and D from swift (Apus apus, Apodiformes).

The blood of the adult swift contains one major (HbA = alpha 2A beta 2) and two minor components (HbD = alpha 2D beta 2 and HbD'). The components were separated by FPLC with a TSK SP-5 PW-column in phosphate buffers, and were eluted with a linear NaCl gradient. HbD' could be detected only in freshly prepared hemolysates with the sensitive FPLC separation method. The globin chains were separated on a cation exchanger (CM-cellulose), the tryptic peptides by HPLC with a RP-2 LiChrosorb column. Their amino-acid sequences were determined by automatic Edman degradation with the film- or gas-phase method. For the alpha A-, alpha D- and beta-chains, peptide alignment was achieved by homologous comparison with the corresponding chains of the greylag goose (Anser anser). The structural significance of the substitutions was examined with the aid of molecular graphics. The oxygen-binding properties of the stripped hemolysate and of HbA and HbD and their dependence on pH, temperature and inositol polyphosphate are presented and discussed with reference to molecular structures and hypothermy that occurs during torpidity.

Amino Acid Sequence↗
PubMed1989

High-altitude respiration of falconiformes. The primary structures and functional properties of the major and minor hemoglobin components of the adult White-Headed Vulture (Trigonoceps occipitalis, Aegypiinae).

The primary structures of the hemoglobin components Hb A and Hb D of White-Headed Vulture (Trigonoceps occipitalis) are presented. The globin chains were separated on CM-Cellulose in 8M urea buffer, the components by FPLC in phosphate buffers. The amino-acid sequences were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid phase and gas-phase sequenators. The sequences differ from those of European Black Vulture by only one mutation in the alpha A-chains (alpha 137). The alpha D-chains and the beta-chains are identical. This means that for the first time identical minor components in birds have been found. An updated list of identical globin chains is presented. Hb D exhibited a higher oxygen affinity than Hb A. At pH 7.5 and 38 degrees C P50 values of 0.80 and 0.64 kPa (6.0 and 4.8 mm Hg), respectively. Both hemoglobins showed similar Bohr factors displayed a pronounced sensitivity to inositol hexakis(phosphate), which increased P50 values of Hbs A and D to 4.0 and 3.6 kPa (30 and 26 mm Hg), respectively. The molecular and physiological significance of the findings is discussed with special reference to oxygen transport by hemoglobin at high altitude.

Altitude↗
PubMed1989

Carnivora: the primary structure of Weddell Seal (Leptonychotes weddelli, Pinnipedia) hemoglobin.

The hemoglobin of Weddell Seal (Leptonychotes weddelli, Pinnipedia) comprises two components with identical beta-chains. The alpha-chains differ in positions 15 (Gly/Asp) and 57 (Ala/Thr). We present the primary structure of the chains which have been separated by reversed-phase high-performance liquid chromatography. The sequences have been determined by automatic Edman-degradation with the film-technique or the gas-phase method, using the native chains and the tryptic peptides of the oxidized chains. Compared to the corresponding human chains we found 22 substitutions in the alpha-chains and 14 in the beta-chains. In the alpha-chains exchanges involve one heme- and three alpha 1/beta 1-contacts. In the beta-chains one heme contact, one alpha 1/beta 1- and one alpha 1/beta 2-contacts are substituted. The sequences are compared to those of other Pinnipedia and Arctoidea hemoglobins.

Amino Acid Sequence↗
PubMed1989

The thiol proteinases from the latex of Carica papaya L. IV. Proteolytic specificities of chymopapain and papaya proteinase omega determined by digestion of alpha-globin chains.

The proteolytic specificities of chymopapain and papaya proteinase omega were investigated by using the alpha-chains of manatee and mole haemoglobin, whose primary structures are known, as substrates. The resulting peptides from each enzymatic cleavage were isolated by gel filtration on Sephadex G-25, followed by reversed-phase HPLC of the separated peaks and, in some cases, further purified by preparative thin-layer electrophoresis. The purified peptides were then identified on the basis of their amino-acid composition. The proteolytic specificities of chymopapain and papaya proteinase omega, deduced from the experimental cleavage patterns, are compared to that of papain. As in the case of papain, the specificity-determining factor is the amino-acid residue of the substrate that will be bound in subsite S2 (the next but one from the scissible bond). Aromatic residues in this position, preferred by papain, are not important for chymopapain and papaya proteinase omega. Cleavages preferentially occur when S2 is occupied by leucine, valine or threonine. For chymopapain, proline in position S2 also causes cleavage.

Amino Acid Sequence↗
PubMed1989

The primary structure of electric ray hemoglobin (Torpedo marmorata). Bohr effect and phosphate interaction.

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.

Amino Acid Sequence↗
PubMed1989

Comparison of insect hemoglobins (Erythrocruorins) from Chironomus thummi thummi and Chironomus thummi piger (Diptera). The primary structure of the monomeric hemoglobin CTP III.

The monomeric hemoglobin fractions of Chironomus thummi thummi (CTT) and Chironomus thummi piger (CTP) differ in the ratio of their components. The determination of the primary structure of the component CTP III was achieved by automatic Edman degradation of the native chain, the tryptic peptides and the C-terminal fragment, obtained by cleavage at the single tryptophan residue. It revealed two chains in the ratio 1:1 which share the ambiguity threonine/isoleucine in position 57 with CTT III. Whereas one chain is identical to the CTT III hemoglobin, the other differs in having isoleucine in position 105 and alanine in position 134. The CTP monomeric hemoglobin fraction comprises 8% of a component (CTP IV A) with a more negative charge than CTT IV but with an identical sequence up to position 44. This study reveals a very high polymorphism within Chironomus species and points out the need for more data at the gene level in order to provide better understanding of this striking phenomenon.

Amino Acid Sequence↗
PubMed1989

Allosteric transition in hemoglobin (alpha 2A beta 2I) from the rhynchocephalian reptile relict Sphenodon punctatus.

The major hemoglobin component Hb A of the tuatara, Sphenodon punctatus, a relict of the rhynochocephalian reptiles that lived 200 million years ago, was investigated in the light of the apparent contradiction inherent in an effect of organic phosphate cofactors on the oxygen affinity of hemoglobins exhibiting hyperbolic oxygen equilibrium curves. The heterotropic allosteric effect of ATP, the major erythrocytic cofactor in the tuatara, is shown to be correlated with distinct homotropic interactions (Hill's cooperativity coefficient at half-saturation, n50, attaining 1.3-1.5 above pH 7.5), and with free energies of heme-heme interaction (4.7 kJ.mole-1 at pH 7.2) which resemble those in other vertebrate hemoglobins that exhibit higher n50 values. Curiously, chloride ions increase hemoglobin-oxygen affinity below pH +/- 7.2. The possible mechanisms underlying the effects of ATP and chloride are discussed.

Adenosine Triphosphate↗