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Biomedical subjects

G Braunitzer

Publications and source records attributed to G Braunitzer.

At least 127 records · Page 7Linked to original sources

Primary structure, biochemical and physiological aspects of hemoglobin from South American lungfish (Lepidosiren paradoxus, Dipnoi).

The South American Lungfish has only one hemoglobin component. The complete amino-acid sequence of this hemoglobin is presented. A large quantity of carbonate dehydratase from the lungfish erythrocytes was also isolated. The carboxymethylated chains, obtained by separation of globin on DEAE-Sephacel, were submitted to tryptic digestion and chemical cleavage. The isolation of tryptic peptides was achieved either by Dowex-50 chromatography or by high performance liquid chromatography. The alignment of peptides was performed by homology with the previously established sequences of the carp and goldfish hemoglobins. The overlapping peptides confirmed this sequence. The alpha chains have 143 residues, the beta chains 147. The relation between the primary structure and the physiological properties of lungfish hemoglobin are discussed.

Amino Acid Sequence↗

[The primary structure of hemoglobin from goldfish (Carassius auratus)].

The primary structures of the alpha- and beta-chains from goldfish hemoglobin are given. The globin chains were separated by gel filtration after air-oxidation of globin. After chemical and enzymatical cleavage of the chains, the peptides were isolated by gel filtration and ion exchange chromatography on Dowex. The fish-chains have one residue more than the human chains. The alpha-chain is acetylated at the amino-terminal residue and has no cysteine. Compared with the human chains there are 66 amino-acid differences in the alpha- and 72 in the beta-chains. The implication of these differences for the physiology of the hemoglobin molecule of goldfish is discussed.

Amino Acid Sequence↗

Hemoglobin of the adult white stork (Ciconia ciconia, ciconiiformes). The primary structure of alpha A- and beta-chains from the only present hemoglobin component.

The hemolysate obtained from erythrocytes of the adult White Stork (Ciconia ciconia) contains only one hemoglobin component, identified to be HbA. The complete primary structures of alpha A- and beta-chains are presented. The minor hemoglobin component HbD with alpha D-chains usually present in adult avian species was not detected by the White Stork. The sequence was determined by automatic Edman degradation of tryptic peptides and in the case of beta-chains additionally of the C-terminal peptide obtained by chemical cleavage at the Asp-Pro bond. Homologous comparison with the Greylag Goose (Anser anser) hemoglobin showed that the alpha A-chains differ by 23 amino-acid exchanges, the beta-chains by 17. Four of the substitutions in the alpha A-chains are in the alpha 1 beta 1-contact points, one in the alpha 1 beta 2-contacts and one in the amino acids near the heme. The amino-acid substitutions of the White Stork hemoglobin as compared to the other avian hemoglobins are discussed. We suggest that alpha D-chain is persistence of an embryonic gene.

Amino Acid Sequence↗

[Hemoglobins of reptiles. Expression of alpha-D-genes in the turtles, Chrysemys picta bellii and Phrynops hilarii (Testudines)].

The hemoglobins of two turtles (Testudines)--Chrysemys picta bellii (suborder Cryptodira) and Phrynops hilarii (suborder Pleurodira)--were investigated. In both specimens we found two hemoglobin components with two distinct alpha-chains. The alpha-chains of the component HbD of Chrysemys picta bellii and of the component CII of Phyrynops hilarii belong to the alpha D-type, which has so far been reported to occur only in birds. The complete amino-acid sequences of both alpha D-chains are presented. Our further investigations on hemoglobins of other reptiles (Crocodilia, Lacertilia, Serpentes) did not give any evidence for the expression of alpha D-globin genes in the species examined. These findings are discussed with especial reference to the physiology of respiration. It is supposed that alpha D-genes were of certain significance in earlier times. There are findings suggesting that alpha D-genes are embryonic genes with persistent expression in many adult birds and turtles.

Amino Acid Sequence↗

The primary structure of monomeric beta-lactoglobulin I from horse colostrum (Equus caballus, Perissodactyla).

beta-Lactoglobulin-like proteins were detected in horse colostrum and normal milk using immunological techniques. In contrast to the beta-lactoglobulins sequenced so far these proteins are monomeric and genetically not homogenous. In this paper we report the first primary structure of a monomeric beta-lactoglobulin from horse colostrum. By means of an automatic liquid-phase sequenator the sequence of peptides obtained by tryptic digestion and by cyanogen bromide cleavage was determined. A limited tryptic digestion and hydrolysis with chymotrypsin provided the necessary overlapping peptides. The horse beta-lactoglobulin I consists of 162 amino acids, among these four cysteine, six methionine residues and one tryptophan residue. Homologous comparison with bovine beta-lactoglobulin A shows an unexpectedly great difference of 72 amino acids (or 44%). Thirteen of these exchanges are explained as two-point mutations. We found that the free thiol group, localized at position 121 or in equal amounts at positions 119 and 121 in bovine beta-lactoglobulin, is absent in beta-lactoglobulin I from horse colostrum. In position 121 a tyrosine substitution for cysteine was found. The amino-acid exchanges of the horse beta-lactoglobulin I as compared to the other beta-lactoglobulins are discussed.

Amino Acid Sequence↗

Amino-acid sequence of gayal hemoglobin (Bos gaurus frontalis, Bovidae).

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.

Amino Acid Sequence↗

Phosphate-haemoglobin interaction. The primary structure of the haemoglobin of the African elephant (Loxodonta africana, Proboscidea): asparagine in position 2 of the beta-chain.

The primary structure of the haemoglobin of the African Elephant (Loxodonta africana) is reported. The sequence was determined by means of a sequenator. The haemoglobin differs in 26 amino acids in the alpha-chains and in 27 in the beta-chains from that of adult human haemoglobin. The haemoglobin of the African Elephant, like that of the Indian Elephant and Ilama, has only 5 binding sites for polyphosphate. This finding explains the low p(O2)50 value in whole blood as a result of the lower 2,3-bisphosphoglycerate-haemoglobin interaction. This is discussed in relation to aspects of respiratory physiology; some points are also of interest with regard to the Second Punic War and Hannibal's crossing of the Alps.

2,3-Diphosphoglycerate↗

Sequence homology between phospholipase and its inhibitor in snake venom. The primary structure of the inhibitor of vipoxin from the venom of the Bulgarian viper (Vipera ammodytes ammodytes, Serpentes).

We are presenting the first primary structure of a snake venom inhibitor. It was isolated from the neurotoxin vipoxin of the Bulgarian Viper (Vipera ammodytes ammodytes, Serpentes) which represents a complex of a strong toxic basic protein with phospholipase A2 activity (2 isoenzymes) and the nontoxic acidic component functioning as its inhibitor. The sequence was established by automatic degradation in a liquid phase sequenator on the S-carboxymethylated chain and on the peptides obtained by tryptic hydrolysis of the oxidized chain. A limited tryptic digestion of the oxidized chain provided the necessary overlapping peptides. The inhibitor consists of 122 amino-acid residues including 14 cysteine and 10 tyrosine residues and is thus similar to the phospholipases from snake venoms. A comparison of the inhibitor sequence with the primary structure of the phospholipase A2 (CM-II) from the Horned Adder (Bitis nasicornis) venom shows a surprising homology of 52%. The identical amino acids include the cysteine and tyrosine residues and are generally accumulated in the surroundings of cysteine residues. The histidine (pos. 47) in the active center of the phospholipase A2 is substituted by glutamine in the inhibitor, but the tryptophan (pos. 30) which is essential for the enzymatic activity is present. The significant homology between enzyme and inhibitor in the vipoxin complex is believed to originate from a gene duplication. The relatively late development of the reptiles and the snake venom complex explains the highly preserved structure compared to other enzyme-inhibitor systems.

Amino Acid Sequence↗

Hemoglobin D "Los Angeles" in an Austrian family: biochemical identification, clinical aspects, and kindred study.

During a screening program for gestational diabetes, hemoglobin D "Los Angeles" (beta 121 Glu----Gln) was detected by HPLC in an overweight but healthy pregnant Austrian woman. The chromatogram of the hemolysate revealed an unusual splitting of the hemoglobin A1 peak. Sequential analysis of the abnormal peptide indicated hemoglobin D "Los Angeles" heterozygosity in the patient. This is the first description of this variant in Germanic-appearing people. In a kindred study of 49 of the 57 living family members spanning four generations, 22 were heterozygous for hemoglobin D "Los Angeles". How this gene got to this region of Austria is unknown, but transfer via Iran and Turkey seems likely.

Austria↗

[Perissodactyla: the primary structure of hemoglobins from the lowland tapir (Tapirus terrestris): glutamic acid in position 2 of the beta chains].

The hemoglobins from a lowland tapir (Tapirus terrestris) were analysed and the complete primary structure is described. The globin chains were separated on CM cellulose column in 8M urea and the amino-acid sequences were determined in the liquid phase sequenator. The results show that globin consists of two alpha chains (alpha I and alpha II) and beta major and beta minor components. The alpha chains differ only at one position: alpha I contains aspartic acid and alpha II glycine. The beta chains are heterogeneous: aspartic and glutamic acid were found at position beta 21 and beta 73 of the beta major components and asparagine and serine at position beta 139. In the beta minor components four positions were found with more than one amino acid, namely beta 2, beta 4, beta 6 and beta 56. The sequences are compared with those of man, horse and rhinoceros. Four residues of horse methemoglobin, which are involved in the alpha 1 beta 1 contacts are substituted in tapir hemoglobins. In the alpha chains: alpha 107(G14)Ser----Val, alpha 111-(G18) Val----Leu, alpha 115(GH3) Asn----Asp or Gly; in the beta chains: beta 116(G18) Arg----Gln. The amino acid at beta 2 of the major components is glutamic acid while glutamine and histidine are found in the minor components. Although glutamic acid, a binding site for ATP, does not interact with 2,3-bisphosphoglycerate, glutamine and histidine in the minor components are responsible for the slight effect of 2,3-bisphosphoglycerate on tapir hemoglobin.

Amino Acid Sequence↗

[Hemoglobins of thecommon starling (Sturnus vulgaris, Passeriformes). The primary structures of the alphaA, alphaD and beta chains].

The primary structures of the major hemoglobin component HbA (alpha A- and beta-chains) and the minor component HbD (alpha D-chains, beta-chains are identical with those of HbA) of the Starling (Sturnus vulgaris) are given. The order Passeriformes, to which this species belongs, represents 5/8 of all species of birds. Comparing Starling and Greylag Goose (Anser anser) hemoglobins, HbA alpha A-chains differ by 20 amino acids or 23 nucleotides (3 two point mutations), beta-chains by 14 amino-acid and nucleotide exchanges. Eight substitutions modify alpha 1-beta 1 contacts and one phosphate contact (beta 2(NA2)His----Gln). In both chains some histidine residues are substituted by neutral amino acids. Comparing Starling and Pheasant (Phasianus colchicus colchicus) hemoglobins, HbD alpha D-chains differ by 33 amino acids or 39 nucleotides (6 two point mutations). Five alpha 1-beta 1 contacts, one alpha 1-beta 2-contact and one heme contact are changed. Valin was found in the N-terminal position of Starling alpha D-chains instead of methionin which is the N-terminus in all other avian alpha D-chains so far investigated. Not only alpha A- and beta-chains, but also alpha A- and alpha D-chains differ significantly from each other in the mutation rates. Substitutions are discussed in relation to evolution, function and physiology.

Amino Acid Sequence↗

[Pre- and perinatal oxygen transport in mammals: the embryonic hemoglobins of the domestic pig (Sus scrofa domestica)].

Pigs express two globin genes of beta-type, the epsilon- and chains during their embryonic stage. With the alpha- and epsilon-chains they form four embryonic hemoglobins. We describe here in detail the experimental procedures for sequencing the epsilon- and chains from the pig (Sus scrofa domestica) and we discuss the data with respect to their special functional properties. From the components Gower I and Heide I, we obtained all embryonic chains by chromatography on CM-Cellulose. The sequence of the tryptic peptides of the beta-type chains was established by automatic Edman-Begg degradation. They were aligned by comparison with the corresponding human chains. The epsilon-chains from man and pig differ in 20 positions, porcine and epsilon-chains only in 4 positions. Up to now these have only been found in pigs. A fetal hemoglobin (gamma-chains) was not observed. As a result of this work the sequences of all peptide chains of pig's hemoglobin are determined.

Amino Acid Sequence↗

[Initial description of hemoglobin D Punjab in an Austrian family].

Haemoglobin D Punjab was detected in a slightly overweight, but otherwise healthy pregnant woman when she was tested for gestational diabetes within the framework of a screening programme. Chromatographic evaluation of the haemolysate by high-pressure liquid chromatography (HPLC) revealed an unusual "splitting" of the A1 peak into two minor peaks. A diabetes-independent haemoglobin variant was suspected and further investigations, including electrophoresis, purification and sequential analysis of the tryptic peptide, identified the abnormal haemoglobin as haemoglobin D Punjab (beta 121 Glu-Gln). This is the first report of this haemoglobin variant in Austria. Various possible modes of geographical spreading of the gene from Punjab (India) are discussed, the land-route via Turkey being the most favourable hypothesis in this case. An investigation of 6 out of 7 living members of the family was undertaken. In 3 instances haemoglobin D Punjab was confirmed by HPLC and electrophoresis. The investigation of the family is currently being expanded to include a total of five generations.

Adult↗

[Identification of hemoglobin D Punjab (beta 121 glu replaced by gln) in an Austrian family. Sequence analysis of the abnormal tryptic peptide beta XTp13].

In the course of a screening programme for gestational diabetes an abnormal haemoglobin fraction was detected by high-performance liquid chromatography (HPLC), used for Hb A1c-quantification. Cellulose acetate electrophoresis revealed a heterozygote haemoglobinopathy with approximately equal amounts of Hb A1 and of an abnormal haemoglobin which migrated in the position of Hb S under the conditions used. Preparative separation of these haemoglobin components was performed by use of a DEAE-cellulose column and standard conditions. alpha- and beta-chains were isolated with CM-sepharose and buffer containing 8M urea. The abnormal component of the aberrant haemoglobin was found to be the beta-chains in reconstitution experiments with globin-chains and haemin. A tryptic hydrolysate of the isolated abnormal beta-chains was analysed by means of HPLC and a C2 reverse phase (RP2). Rechromatography of the abnormal fractions on a C18 reverse phase (ODS) led to a pure preparation of peptide beta XTp13. The amino acid sequence analysis of this peptide showed an exchange of glutamic acid to glutamine in position beta 121 (beta 121 Glu----Gln). By these means evidence was obtained for the existence of a heterozygote Hb D Punjab state in the observed patient.

Adult↗

Proline- and alanine-rich N-terminal extension of the basic bovine beta-crystallin B1 chains.

The amino acid sequence of the N-terminal region of the two basic bovine beta-crystallin B1 chains has been analyzed. The results reveal that beta B1b is derived in vivo from the primary gene product beta B1a by removal of a short N-terminal sequence. It appears that the beta B1 chains have the same domain structure as observed in other beta- and gamma-crystallin chains. They have, however, a very long N-terminal extension in comparison with other beta-chains. This extension is mainly composed of a remarkable Pro- and Ala-rich sequence, which suggests an interaction of these structural proteins with the cytoskeleton and/or the plasma membranes of the lens cells.

Alanine↗

The analysis of a protein-polymorphism. Evolution of monomeric and homodimeric haemoglobins (erythrocruorins) of Chironomus thummi thummi (Insecta, Diptera).

The evolutionary history of 12 Chironomus thummi thummi (CTT) haemoglobins of known primary structures was reconstructed by the maximum parsimony method. This reconstruction demonstrates that the 12 CTT haemoglobin lineages originated monophyletically from a common ancestor within early Insecta and have the lineage to monomeric blood worm haemoglobin as their closest sister group. It can be further deduced that the earliest ancestral CTT haemoglobins were monomers and that a branch to all extant dimeric CTT haemoglobins emerged later in phylogeny near the base of Chironomidae, but perhaps still before Chironomus itself evolved. This ancient, pre-Chironomus history suggests that among insect taxa, now lacking expressed globins, remnants of globin genes might exist as unexpressed pseudogenes. By the parameter of base replacement frequencies, CTT haemoglobins appear as relatively slow-evolving proteins, showing a preponderance of guanine in equilibrium adenine transitions at the first nucleotide position of the codons but not at the second. The most conservatively-evolving amino acid positions are haem contacts; the next most conservative are in interhelical contacts and interior positions involved in stabilization of tertiary structure. Further elucidation of the phylogenetic origins and adaptive evolution of the multiple haemoglobins found in Chironomus will be possible by the maximum parsimony method once haemoglobins or, in their absence, haemoglobin pseudogenes are sequenced in species throughout Chironomidae and related taxa.

Amino Acid Sequence↗

[Primary structure of alpha and beta chains from the major hemoglobin component of the magpie goose (Anseranas semipalmata, Anatidae)].

The amino acid sequence of the alpha and beta chains from the major hemoglobin component (HbA) of Australian Magpie Goose (Anseranas semipalmata) is given. The minor component with the alpha D chains was detected, but only found in low concentrations. By homologous comparison, Greylag Goose hemoglobin (Anser anser) and Australian Magpie Goose alpha chains differ by 13 amino acids or 17 nucleotide (4 two point mutations) exchanges, beta chains by 6 exchanges. Seven alpha 1 beta 1 contacts are modified by substitutions in positions alpha 30-(B11)Glu leads to Gln, alpha 34(B15)Thr leads to Gln, alpha 35(B16)-Ala leads to Thr, alpha 36(B17)Tyr leads to Phe, beta 55(D6)Leu leads to Ile, beta 119(GH2)Ala leads to Ser and beta 125(H3)Glu leads to Asp. Further, one alpha 1 beta 2 contact point was changed in beta 39(C5)Gln leads to Glu. Mutation in this position, except in two abnormal human hemoglobins, was not found in any species. Amino acid exchanges between hemoglobin of Australian Magpie Goose and other birds are discussed.

Amino Acid Sequence↗