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Biomedical subjects

G Braunitzer

Publications and source records attributed to G Braunitzer.

At least 163 records · Page 9Linked to original sources
PubMed1982

[Hemoglobins, XLVII. Hemoglobins of the bar-headed goose (Anser indicus): primary structure and physiology of respiration, systematic and evolution].

The primary structures of the alpha- and beta-chains of the main component of Bar-headed Goose (Anser indicus) are given. By homologous comparison with the hemoglobin of the Grey-Lag Goose (Anser anser) 3 differences were found in the alpha-chains, 1 difference in the beta-chains. In position alpha 119 H2Ala and beta 125 H3Asp alpha 1 beta 2-contact points are changed. The mutation alpha 63 E12Val brings a drastic change in tertiary structure of the alpha-chains of Bar-headed Goose: the helices E and B are moved apart by 1.5 A as there is no room for the larger side chain. This is probably the reason for a slightly higher intrinsic oxygen affinity of Bar-headed Goose hemoglobin. The bindings of inositol pentaphosphate on hemoglobin are identical in Grey-Lag Goose and Bar-headed Goose (contact points are not mutated). The reason for the increased difference in oxygen affinity by binding of inositol pentaphosphate is probably caused by two mutations in alpha 1 beta 2-contact points. It suggests that these two mutations are the reason for a different interaction between alpha- and beta-chains under the influence of inositol pentaphosphate by Grey-Lag and Bar-headed Goose hemoglobins. The difference in the primary structure of the Grey-Lag and Bar-headed Goose hemoglobins suggests that the Bar-headed Goose is not the genus of anser. Unfinished experiments (about 80% of the sequences) of White-fronted Goose (Anser albifrons a.) and Snow Goose (Anser caerulescens c.) show no exchanges with Grey-Lag Goose hemoglobin. The Canada Goose (Branta canadensis), however, which belongs to the genus Branta, has a number of substitutions similar to the Bar-headed Goose hemoglobin. These changes in primary structure suggest that Grey-Lag Goose and Bar-headed Goose are separated by a period of 9-15 Million years. This would support the hypothesis that the two species of goose became geographically separated by the elevation of the Himalayas.

Amino Acid Sequence↗
PubMed1982

[The primary structure of the hemoglobin gamma-chains of fetal sheep (Ovis ammon) and goat (Capra aegagrus), Artiodactyla].

The complete primary structures of the gamma-chains of fetal sheep (Ovis ammon) and goat (Capra aegagrus) hemoglobins are presented. The chains were isolated by chromatography on carboxymethyl cellulose CM-52. The primary structures of both chains were established by automatic Edman degradation, mainly on the tryptic peptides. The N-terminal regions were sequenced on the chains. Large C-terminal peptides were isolated and sequenced after acidic hydrolysis of the Asp-Pro bond (gamma 99/100). The peptides were aligned by their homology with the bovine gamma-chains. The gamma-chains of sheep and goat differ in 5 amino acid residues. Compared to bovine gamma-chains there are 12 and 10 exchanges, respectively. The influence of the primary structure on the intrinsic oxygen affinity of hemoglobins is discussed.

Amino Acid Sequence↗
PubMed1982

[Hemoglobins, XLVIII: the primary structure of hemoglobin of the Indian elephant (Elephas maximus, Proboscidea): beta 2 = Asn].

The primary structure of the hemoglobin of the Indian Elephant (Elephas maximus) is given. The sequence was determined automatically in a sequenator. By homologous comparison with adult human HbA, the alpha-chains differ by 24 exchanges and the beta-chains by 27 exchanges. Furthermore, we report p(O2)50 values with regard to altered contact sites with 2,3-bisphosphoglycerate in Indian elephant hemoglobin. Our findings explain the low p(O2)50 and the reduced interaction with 2,3-bisphosphoglycerate. Elephant hemoglobin has, like that of the Llama, only five phosphate binding sites. In addition, we have made an attempt to relate these results to aspects of respiratory physiology. Some implications of these biochemical and physiological results, concerning the Second Punic War and Hannibal's Alp transition, are given.

Amino Acid Sequence↗
PubMed1982

[Primary structure of the hemoglobins from the Egyptian fruit bat (Rousettus aegyptiacus, Chiroptera)].

The hemoglobin of the egyptian fruit bat (Rousettus aegyptiacus) has only one component. The alpha and beta chains were separated by chromatography on CM-52 cellulose. The complete primary structures of both chains were established by automatic Edman degradation of the chains and the tryptic peptides. The alignment was done by homology with alpha and beta chains of adult human hemoglobin. A comparison of these two hemoglobins shows an exchange of 14 amino acid residues in the alpha chains and of 19 in the beta chains. These numbers are very low, considering the long phylogenetic distance between primates and megachiroptera. In the surroundings of the heme we found one substitution in each chain. In the alpha 1 beta 1-subunit interface one and two residues are exchanged respectively in the alpha and beta chains. The primary structure points to a normal oxygen affinity of the bat hemoglobin which was also found by Jürgens et al.

Amino Acid Sequence↗
PubMed1982

[The primary structure of the hemoglobin from a white rhinoceros (Ceratotherium simum, perissodactyla): beta 2 Glu].

The hemoglobin from a white rhinoceros (Ceratotherium simum) was analysed and the complete primary structure of the alpha and beta chains is described. The globin chains were separated on CM-cellulose column in 8M urea buffer. The amino acid sequences were mainly determined by automatic degradation of tryptic peptides in the sequenator. The results show, that globin consists of one alpha- and several beta-chain types. The beta chains differ at position beta 62 where the amino acids threonine, serine and alanine were identified and at position beta 116 where glutamine or lysine were found. The sequences are compared with those of horse, wild ass and zebra hemoglobin. Five amino acid residues of horse hemoglobin, which are involved in the alpha 1 beta 1 contacts are substituted in white rhinoceros hemoglobin. These substitutions are alpha 35 Gly leads to Ser, alpha 107 Ser leads to Val, alpha 111 Val leads to Leu, alpha 115 Asn leads to Gln and beta 116 Arg leads to Gln or Lys. Furthermore glutamic acid was found at position beta 2 of rhinoceros hemoglobin. In most mammalian hemoglobins the amino acid at this position is histidin which is one of the residues that binds, 2,3-bisphosphoglycerat in deoxyhemoglobin. In this way 2,3-bisphosphoglycerat controls the oxygen affinity of hemoglobin.

Amino Acid Sequence↗
PubMed1982

Caiman crocodylus hemoglobin. Complete primary structures of alpha and beta chains; phylogenic and regulatory aspects.

In some reptiles, the hemoglobin oxygen affinity is lowered by CO2 and not by the usual phosphate cofactors. To understand the molecular mechanism of this regulation, Caiman crocodylus hemoglobin's primary structure has been determined. The alignment of the 141 residues of the alpha chain as well as the 146 of the beta chain were obtained by classical method of sequence analysis and are compared with some mammalian, avian, amphibian, and fish hemoglobin chains. Furthermore, from these sequences, it is possible to explain the non-interaction of phosphorylated cofactors with the caiman deoxyhemoglobin on the basis of mutations of the amino acids responsible for their fixation on the beta chain. Among these residues only lysine beta 82 is unchanged. In addition a site has been proposed for the fixation of HCO3- which involves ionic bonds with serine beta 1 and glutamic acid beta 144 (Perutz et al. (1981) Nature 291, 682-684) (1).

Alligators and Crocodiles↗
PubMed1981

Studies on the evolutionary relationships between hemoglobins in Chironomus pallidivittatus and C. tentsans. I. Isolation and immunological analysis of monomeric and dimeric hemoglobins.

The monomeric hemoglobins of Chironomus tentans and C. pallidivittatus have been isolated and separated into their respective components by gel chromatography on Sephadex G-75 and ion-exchange chromatography on DEAE-Sephacel. The amino acid compositions of the purified components are given. The sequence of the 30 N-terminal amino acid residues of one of the monomeric components (Hb I from C. pallidivittatus) was determined and found to be identical in almost all of its parts with the monomeric hemoglobins of C. thummi (CTT III and CTT IV). Antibodies against the monomeric hemoglobins Hb I and Hb IIc and the dimeric fraction were highly specific and no cross reaction between dimeric and monomeric hemoglobins could be demonstrated. The antibodies against the monomers crossreact with the monomeric hemoglobins CTT III and CTT IV of C. thummi. Taken together with genetic data, the immunological results indicate that divergence of monomeric from dimeric forms was an early event in the evolution of the various hemoglobins in Chironomus.

Amino Acid Sequence↗
PubMed1981

Adaptation of hemoglobin function to subterranean life in the mole, Talpa europaea.

In order to understand the mechanism responsible for the high oxygen affinity of mole blood, we investigated in the mole. Talpa europaea, red cell parameters that determine hemoglobin function. We have found that the oxygen half saturation pressure (P50) of mole blood is 2.85 kPa (21.4 Torr) at pCO2 4.7 kPa, pH 7.4 and 37 degree C. The concentration of 2,3-diphosphoglycerate (2,3-DPG) averaged 5.3 mmol/l in red cells. In addition, we have determined P50 in hemoglobin solutions at various concentrations of 2,3-DPG at an assumed intraerythrocytic pH of 7.2 and 37 degree C. These data were used to calculate the association constants of 2,3-DPG to mole hemoglobin. P50 was 1,89 kPa (14.2 Torr) in hemoglobin solutions without 2,3-DPG. The response to 2,3-DPG was relatively low. Noteworthy, CO2 did not affect the oxygen affinity at constant pH in the presence of 2,3-DPG. Our results suggest that the high blood oxygen affinity of the mole can be attributed to a weak interaction of its hemoglobin with 2,3-DPG.

Adaptation, Physiological↗
PubMed1981

Hemoglobins, XXXVIII. Amino acid sequence of a dimeric hemoglobin (erythrocruorin), component VI from Chironomus thummi thummi (CTT VI).

The dimeric hemoglobin CTT VI (Erythrocruorin) was isolated from the hemolymph of the larvae of Chironomus thummi thummi. The globin from CTT VI was subjected to trypsin, limited trypsin and cyanogen bromide digestion. For elucidation of the sequence in the C-terminal region, cleavage with Staphylococcus aureus V8 protease was also carried out. The peptides were separated by gel and ion-exchange chromatography. The handling of some large fragments was facilitated by maleylation and subsequent ion-exchange chromatography with conservation of the maleyl groups. The amino acid sequence was determined by automatic Edman degradation. The order of the peptides was provided by overlaps, but in two cases by homology only (for residues 98 and 99, and 109 and 110). The hemoglobin consists of 2 x 147 amino acids with a molecular weight of 32411. The sequence of CTT VI is compared with a monomeric (CTT III) and a dimeric hemoglobin (CTT II beta) and the human alpha-chains. The structural differences are discussed.

Amino Acid Sequence↗
PubMed1981

[Hemoglobins XL: Sequence analysis of the monomeric hemoglobin CTT IV (erythrocruorin) of Chironomus thummi thummi, Diptera (author's transl)].

The sequence analysis of the monomeric hemoglobin CTT IV is given. The primary structure was determined by automatic Edman degradation of the protein and of peptides obtained by enzymatical or by chemical cleavages. The protein chain consists of 136 amino acids. The primary structure is compared with the primary structure of the human beta-chains and of the monomeric hemoglobin CTT III.

Amino Acid Sequence↗
PubMed1981

[Hemoglobins, XXXVI: The primary structure of a dimeric insect hemoglobin (Erythrocruorin), component IX from Chironomus thummi thummi. Studies on the quarternary structure of the dimeric CTT-hemoglobins (author's transl)].

The primary structure of a dimeric insect hemoglobin (erythrocruorin), component CTT IX (Chironomus thummi thummi) was established by automatic sequence analysis. The alignment of the peptides was facilitated by producing only a few large fragments. The primary structure of CTT IX is compared with the human beta-chains and with CTT III. It is discussed, why for the dimeric CTT-hemoglobins only dimerisation can be observed but no tetramerisation. Experiments were done to locate the binding areas between the subunits in the dimeric molecule. Even after blocking of the alpha-NH2-group by cyanate, the stability of the dimeric molecule is not altered. Therefore the binding regions of the CTT-hemoglobins must be different from those of the tetrameric hemoglobins of vertebrates. Our results lead to a quarternary structure different from that of the hemoglobins of mammalians. This structure explains the possibility of dimerisation, but excludes tetramerisation.

Amino Acid Sequence↗
PubMed1981

[Hemoglobins, XXXVII. The primary structure of a monomeric insect hemoglobin (Erythrocruorin), component CTT IIIa of Chironomus thummi thummi. An anomalous Heme complex: E7 Gln, E11 Ile].

The primary structure of the monomeric hemoglobin CTT IIIa of the midge larva of Chironomus thummi thummi is presented. Cyanogenbromide peptides and tryptic peptides were used for sequence analysis. The primary structure was established with a small number of large peptides. The complete sequencing of the cyanogen bromide peptides was enabled by the C-terminal fixation of arginine. The primary structure of CTT IIIa is compared to the beta-chains of human and to the monomeric component CTT III: CTT IIIa possesses a "tail" of 9 amino acids on the N-terminus, and shows only a small number of identical residues compared to the number that other CTT hemoglobins share with each other. Also the heme complex is unusual: E7 Gln and E11 Ile.

Amino Acid Sequence↗
PubMed1981

Hemoglobins, XLI. The embryonic hemoglobins of mammal. A new hemoglobin, hemoglobin Heide II (Hb HeII: alpha 2 epsilon 2), and demonstration of the hemoglobin structure of gower I (zeta 3 epsilon 2) in the pig embryo.

A new hemoglobin is described. The hemoglobins of pig embryonic erythrocytes are separated by DEAE-Cephacel chromatography. In addition to a small amount of adult hemoglobin, four embryonic hemoglobins are obtained. Each of the hemoglobin components is analysed by globin and hemoglobin electrophoresis on polyacrylamide gels. Two of these hemoglobins are previously described as Hb Gower II (alpha 2 epsilon 2) and Heide I (zeta 2 epsilon 2). A tetrameric hemoglobin consisting of alpha and epsilon chains has been detected. Therefore, this new hemoglobin is named, in analogy, as Hb Heide II (alpha 2 epsilon 2). Furthermore, the other hemoglobin tetramer has been unequivocally identified as zeta 2 epsilon 2. This structure corresponds to Gower I which is only suggested in the human embryo.

Animals↗
PubMed1981

[The sequence of the alpha-amylase inhibitor Hoe-467 A (alpha-amylase inactivator Hoe-467 A) from Streptomyces tendae 4158].

An alpha-amylase inhibitor isolated from Streptomyces tendae, strain 4158 was re-purified by chromatography on CM- and DEAE-cellulose column. Two inhibitors could be characterized: alpha-amylase inhibitor Hoe-467 A (with aspartic acid as N-terminal residue), and alpha-amylase inhibitor Hoe-467 S (with serine as N-terminal residue). The primary structure was determined by automatic Edman-degradation procedures of the aziranized inhibitor and tryptic peptides, derived from digestions of the performic oxidized, aziranized and maleylated inhibitor, respectively. The alpha-amylase inhibitor Hoe-467 A consists of 74 residues and has a calculated molecular weight of 7958. It is composed of all common amino acids except methionine and phenylalanine. Digestion with pepsin was carried out to determine the disulfide bonds. Two fractions could be isolated, containing one cystine each giving information about the positions of the disulfide bridges. The possible clinical application of the inactivator (diabetes mellitus) is pointed out.

Amino Acid Sequence↗
PubMed1981

[Human embryonic haemoglobins. Ac-Ser-Leu-Thr-is the N-terminal sequence of the zeta-chains (author's transl)].

The complete amino acid sequence of the embryonic zeta-chains has been reported in an earlier communication (Aschauer, H., Sanguansermsri, T. & Braunitzer, G. (1981), Hoppe-Seyler's Z. Physiol. Chem. 362, 1159-1162). To elucidate the nature of the N-terminal blocking group, tryptical cleavage of the zeta-chains was carried out and the N-terminal tryptic tetrapeptide was isolated by high performance liquid chromatography on reversed phase (RP 8). The tetrapeptide was digested with pronase and the mixture was subjected to mass spectrometry by chemical ionization. By this method Ac-Ser was found to be the N-terminus. In a second experiment the tetrapeptide was permethylated and analysed by mass spectrometry with electron ionization. The N-terminal sequence was found to be Ac-Ser-Leu-Thr-.

Amino Acid Sequence↗
PubMed1981

[Human embryonic haemoglobins. The primary structure of the zeta chains (author's transl)].

The primary structure of the embryonic zeta-chains of humans is given. Blood was obtained from a case with hydrops foetalis syndrom due to homozygous alpha-thalassemia 1. The zeta-chains were isolated by high performance liquid chromatography on reversed phase (RP8). The peptides for sequence work were generated by chemical methods (cyanogen bromide cleavage and acid cleavage at the Asp-Pro bond) and enzymatic cleavages with trypsin of unmodified and succinylated zeta-chains. The peptides were separated by high performance liquid chromatography and sequenced by automatic N-terminal degradation procedures. The N-terminal residue of the zeta-chains is blocked. Therefore the sequence of the N-terminal tryptic peptide was determined after incubation with chymotrypsin. The zeta-chains are alpha-type chains and consist of 141 amino acid residues. The alignment of the zeta-chains with the human alpha-chains shows 57 amino acid exchanges: Thus it is evident that there is a greater phylogenetic distance between the alpha type chains than between the beta-type chains.

Amino Acid Sequence↗