Biomedical subjects

G Braunitzer

Publications and source records attributed to G Braunitzer.

At least 109 records · Page 6Linked to original sources

PubMed1985

Functional multiplicity and structural correlations in the hemoglobin system of larvae of Chironomus thummi thummi (Insecta, Diptera): Hb components CTT I, CTT II beta, CTT III, CTT IV, CTT VI, CTT VIIB, CTT IX and CTT X.

Larvae of the dipteran insect Chironomus thummi thummi that burrow in fresh-water muds, contain at least 12 hemoglobin (Hb) components of which the functional properties have not been systematically documented, although their amino acid sequences have been elucidated, showing mutually distinct primary structures. We isolated eight components (the monomeric Hbs CTT I, CTT III and CTT IV and the dimeric Hbs CTT II beta, CTT VI, CTT VIIB, CTT IX and CTT X) and measured in each O2 affinity and cooperativity and their pH dependence, and the effects of temperature, NaCl and ATP. The O2 affinities, Bohr- and temperature effects of the isohemoglobins are discussed in relation to mode of life and the microenvironmental conditions to which the larvae are subjected in nature, and with regard to the molecular mechanisms underlying the Hb-oxygenation reactions.

Animals↗

PubMed1985

Primary structure of the hemoglobins from the greater Kudu antelope (Tragelaphus strepsiceros).

The adult greater Kudu antelope has two hemoglobin components, Hb A and Hb B, with one alpha and two beta chains. The complete amino-acid sequences of these three chains are presented. The two beta chains differ only in one residue at position 16 (Gly----Ser) and may be the product of two allelic genes. The primary structure of the chains was determined by sequencing the tryptic peptides after their isolation from the tryptic digest of the chains by high performance liquid chromatography. The alignment of these peptides was deduced from homology with the chains of bovine hemoglobin. Between the Kudu hemoglobins and those of cattle a high degree of homology was found.

Amino Acid Sequence↗

PubMed1985

Determination of the complete amino-acid sequence of subtilisin DY and its comparison with the primary structures of the subtilisins BPN', Carlsberg and amylosacchariticus.

The complete amino-acid sequence of subtilisin DY, an extracellular alkaline proteinase produced by Bacillus subtilis strain DY was determined. This included automated sequence analysis of the whole molecule and its large fragments such as tryptic peptides obtained from the inactivated enzyme, peptides generated by cyanogen bromide, by o-iodosobenzoic acid and by hydroxylamine. The peptides were isolated by gel filtration and by reversed-phase high performance liquid chromatography. The amino-acid sequence of subtilisin DY was determined by overlapping the isolated peptides. It consists of 274 amino-acid residues, like that of subtilisin Carlsberg. By comparison with the structures of the subtilisins Carlsberg, amylosacchariticus and BPN' 32, 80 and 82 amino-acid substitutions were found, which are caused by 37, 102 and 106 nucleotide mutations, respectively. It was found also that 62.5% of the amino-acid residues in the molecules of these four subtilisins are identical with respect to kind and position of the residue, which suggests that these molecules have had a common ancestral precursor. The amino-acid replacement analysis of the four subtilisins leads to the conclusion that they have evolved almost independently.

Amino Acid Sequence↗

PubMed1985

Homology between the primary structures of beta-lactoglobulins and human retinol-binding protein: evidence for a similar biological function?

Two types of beta-lactoglobulins were identified and isolated from horse colostrum: beta-1g I and beta-1g II. The amino-acid sequence of some tryptic peptides from the new monomeric beta-lactoglobulin II was determined and aligned to the other beta-lactoglobulins of known sequence and to the human plasma retinol-binding protein. The comparison of the primary structures of beta-lactoglobulins and human retinol-binding protein shows an unexpectedly high homology of 25%. We found 37 identities among 149 possible homologous residues. Among them is a tryptophan residue at position 19 of beta-lg which might represent the binding site of beta-ionone. These data suggest a common origin of beta-lactoglobulin and human retinol-binding protein and imply that beta-lactoglobulins may be involved in the metabolism of retinol.

Amino Acid Sequence↗

PubMed1985

The primary structure of alpha A- and beta-chains from blue-and-yellow macaw (Ara ararauna, Psittaci) hemoglobin. No evidence for expression of alpha D-chains.

The hemoglobin A of the Blue-and-Yellow Macaw (Ara ararauna) was isolated and characterized. The complete amino-acid sequence of alpha A- and beta-chains is presented. In contrast to some adult avian hemoglobins already investigated, Blue-and-Yellow Macaw hemoglobin is homogenous and contains only one component: HbA. The minor component, HbD, which is usually present in the hemolysate of avian erythrocytes, could not be detected. There is no evidence for the expression of the alpha D-globin gene. Comparison of alpha A- and beta-chains from Blue-and-Yellow Macaw hemoglobin with corresponding chains from Greylag Goose hemoglobin shows 19 amino-acid exchanges between alpha A-chains and 6 between beta-chains. The structure-function relationships of hemoglobin chains and the evolutionary aspects are discussed in view of these results.

Amino Acid Sequence↗

PubMed1985

The primary structure of the hemoglobin of the dogfish shark (Squalus acanthias). Antagonistic effects of ATP and urea on oxygen affinity of an elasmobranch hemoglobin.

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).

Adenosine Triphosphate↗

PubMed1985

The amino-acid sequence of beta-lactoglobulin II from horse colostrum (Equus caballus, Perissodactyla): beta-lactoglobulins are retinol-binding proteins.

beta-Lactoglobulin isolated from horse colostrum is heterogeneous and contains two components: beta-lactoglobulin I and beta-lactoglobulin II. These two proteins are monomeric and show differences in their electrophoretic mobilities, chain lengths and primary structures. The complete amino-acid sequence of beta-lactoglobulin II was determined by automated Edman degradation of the intact protein and of the peptides derived from these by digestion with trypsin or chymotrypsin and by chemical cleavage with cyanogen bromide. Unlike other beta-lactoglobulins which contain 162 amino acids, horse beta-lactoglobulin II is unique in that it contains 166 amino acids. The additional four amino acids represent an insertion between positions 116 and 117 of other beta-lactoglobulins so far sequenced, including horse beta-lactoglobulin I. Sequence comparison of beta-lactoglobulins I and II from horse colostrum reveals 48 amino acid substitutions (30%). Such a diversity between members of the beta-lactoglobulin gene family has not been encountered before. Sequence comparison with bovine beta-lactoglobulin A shows 85 amino acid replacements accounting for 53% of the residues. The structural homology with human retinol-binding protein may reveal similar biological functions and clues to the origin of milk proteins.

Amino Acid Sequence↗

PubMed1985

Studies on yak hemoglobin (Bos grunniens, Bovidae): structural basis for high intrinsic oxygen affinity?

Two types of alpha- and two types of beta-chains are found in the hemoglobin of yak population. The complete amino-acid sequences of the four polypeptide chains were determined. The two alpha-chains differ by two and the two beta-chains by three amino-acid substitutions. The substitution of valine at position 135 in the beta II-chain may be responsible for the high intrinsic oxygen affinity of yak hemoglobin.

Amino Acid Sequence↗

PubMed1985

The primary structure of alpha-amylase inhibitor Z-2685 from Streptomyces parvullus FH-1641. Sequence homology between inhibitor and alpha-amylase.

The native and oxidized alpha-amylase inhibitor Z-2685, isolated from the culture medium of Streptomyces parvullus FH-1641, and its overlapping cleavage products were degraded by the automatic Edman technique. Digestion was carried out with pepsin, thermolysin and trypsin. The alpha-amylase inhibitor is a polypeptide consisting of 76 amino acids with a molecular mass of 8 129 Da. With the exception of methionine and lysine, all naturally occurring amino acids are present. It is interesting that identical regions exist, in particular the sequence Trp-Arg-Tyr common to all four known microbial inhibitor sequences. We believe that the side chains of these three amino acids are important for interacting with the alpha-amylase molecule. Computer alignment enabled us to show a possible binding region in the alpha-amylase molecule which might react with the inhibitors. Furthermore, homology exists to mammalian alpha-amylases. This result is explained by the assumption that the inhibitor evolved from a duplication of the original gene of the enzyme.

Amino Acid Sequence↗

PubMed1985

Mole rat hemoglobin: primary structure and evolutionary aspects in a second karyotype of Spalax ehrenbergi, Rodentia, (2n = 52).

The hemoglobins of the four karyotypes of Spalax ehrenbergi (2n = 52, 54, 58, 60) did not show any differences in their electrophoretic pattern and in high performance liquid chromatography. The complete amino-acid sequence of mole rat hemoglobin (Spalax ehrenbergi), chromosome species 2n = 52, is presented. It was elucidated by automatic Edman degradation of the chains, the tryptic peptides, and the C-terminal peptide obtained by acid hydrolysis of the Asp-Pro bond in beta-chains. The alpha- and beta-chains are identical with those of the chromosome species 2n = 60. A comparison of the hemoglobins of mole rat, mouse, and other rodents shows homology but no indication of adaptation to subterranean life. In all probability alpha 11(A9)Arg and alpha 120(H3)Gly, unique in mole rat among all mammalian hemoglobins, are not involved in high oxygen affinity. The construction of a phylogenetic tree by the maximum parsimony method, based on hemoglobin sequences, made it possible to show that Rodentia originated as a monophyletic clade, and to find the phylogenetic relationship of Spalacidae to other Rodentia (Mus, Rattus, Ondatra, Mesocricetus, Citellus, and Cavia). Among all rodents the slowest rate of nucleotide replacements occurred in the lineage to Spalax (20%) and the fastest in the lineage to Cavia (59%).

Amino Acid Sequence↗

PubMed1985

The primary structure of hemoglobins from the domestic cat (Felis catus, Felidae).

The complete primary structure of the two hemoglobin components of the domestic cat (Felis catus) is presented. The major component (A) accounts for 60-70% whereas the minor component (B) constitutes 30-40% of the total hemoglobin. Separation of the polypeptides was carried out in buffers containing 8M urea on CM-Cellulose. The sequence was studied by Edman degradation of tryptic and cyanogen bromide cleavage products in a liquid phase sequencer. The sequence is compared for homology with human hemoglobin. The beta-chain of the minor components (beta B) has a blocked N-terminal residue identified as acetylserine whereas that of the major component (beta A) is free glycine. The two hemoglobins have identical alpha-chains and differ with respect to their beta-chains at the following positions (beta B/beta A): beta NA1 Ac-Ser/Gly, beta A1 Ser/Thr, beta H17 Ser/Asn and beta HC1 Arg/Lys. The structural and functional aspects of these exchanges are discussed.

Amino Acid Sequence↗

PubMed1985

The primary structure and functional properties of the hemoglobins of a ground squirrel (Spermophilus townsendii, Rodentia).

The hemoglobin of the ground squirrel Spermophilus townsendii consists of two components which are present in a ratio of ca. 2:1. The two hemoglobins have identical alpha-chains, but differ in their beta-chains. We present the primary structures of the alpha- and the two beta-globin chains. Following chain separation by chromatography on carboxymethyl-cellulose CM-52, the amino-acid sequences were established by automatic Edman degradation of the globin chains and the tryptic peptides, as well as of a peptide obtained by acid hydrolysis of the Asp-Pro bond of the beta-chains. The two beta-chains differ by only one amino-acid residue, Ala being present in the main and Asp in the minor component in position 58 (E2). The comparison with human hemoglobin showed only 14 exchanges in the alpha-chains but 33 in the beta-chains. Whereas no contact positions are affected in the alpha-chains, we found four such substitutions in the beta-chains, including one heme contact, two alpha 1/beta 1-contacts, and one alpha 1/beta 2-contact. It seems however, that the substitution found in the beta-chains has no effect on the oxygen affinity.

Amino Acid Sequence↗

PubMed1985

[Hemoglobin of tree sparrows (Passer montanus, Passeriformes): Sequence of the major (Hb A) and minor (Hb D) components].

Blood of the adult Tree Sparrow (Passer montanus) contains two hemoglobin components, Hb A (ca. 85%), Hb D (ca. 15%). They differ in their alpha-chains (alpha A, alpha D), the beta-chains are identical. The complete primary structures of alpha A-, alpha D- and beta-chains are presented. Comparison with the Greylag Goose (Anser anser) hemoglobin (Hb A) showed that the alpha A-chains differ by 22 amino-acid exchanges, the beta-chains by 16. Comparison with the minor component of the Pheasant (Phasianus colchicus colchicus) hemoglobin (Hb D) showed that the alpha D-chains differ by 34 amino-acid exchanges. Proline is found incorporated in an internal position of an alpha-helix (pos. 124, H7). In comparison to that of the Starling (Sturnus vulgaris) the ratio of amino-acid exchanges for beta: alpha A: alpha D chains is 1 : 7 : 4; in comparison to other birds this ratio is found to be 1 : 2 (1.4-2.2):3 (2.2-4).

Amino Acid Sequence↗

PubMed1985

[The hemoglobin of adult Andean condors (Vultur gryphus, Cathartiformes). The amino acid sequence of the major (HbA) and minor component (HbD)].

The complete amino-acid sequence of the alpha A- and the beta-chains of the major component (HbA) and the alpha D- and the beta-chains of the minor component (HbD) of Andean Condor (Vultur gryphus) is presented. The minor component with the alpha D-chains is present in smaller amounts (17%) than in other birds (25%). The comparison with the corresponding chains of Greylag Goose (Anser anser) shows 17 different amino acids (17 nucleotides, only one-point mutations) in the alpha A-chains and 8 (8 nucleotides) in the beta-chains. The alpha D-chains differ from those of the pheasant (Phasanius cholchicus cholchicus) in 24 amino acids (27 nucl., 3 two-point mutations). Seven alpha 1 beta 1-, one alpha 1 beta 2-, three alpha 1 alpha 1-contacts and one beta 1 beta 1-contact are exchanged. The systematy of Cathartiformes, Ciconiiformes and Phoenicopteriformes is discussed, based on the amino-acid exchanges of all known adult hemoglobins of birds.

Amino Acid Sequence↗

PubMed1984

Homology between the primary structures of the major bovine beta-crystallin chains.

Partial amino acid sequences of six major subunits of bovine beta-crystallin have been determined by automatic liquid-phase Edman degradation and the dansyl-Edman procedure, complemented by amino acid analyses of peptides. The results show that, including the previously established beta Bp sequence [H. P. C. Driessen et al. (1981) Eur. J. Biochem. 121, 83-91], there exist at least seven primary gene products in bovine beta-crystallin, which exhibit 40% or more sequence homology. Two of the gene products are completely identical except for the presence in one of them of 17 additional residues at the N terminus, possibly caused by differential splicing of the same primary RNA transcript. The rate of evolutionary change of the beta chains (4% sequence change per 100 X 10(6) years) is about equally slow as that of alpha-crystallin, and the gene duplications giving rise to the different chains must have occurred very early in vertebrate evolution. The beta chains can be divided into two groups, according to sequence homology and presence of deletions/insertions and C-terminal extension, on which basis a new, rational nomenclature for the beta subunits is introduced. The N-terminal extensions of all beta chains are very different in length and sequence, even between homologous beta chains in different species. Possible explanations for this finding are discussed.

Amino Acid Sequence↗

PubMed1984

Oxygen binding properties of hemoglobin from the white rhinoceros (beta 2-GLU) and the tapir.

The beta-chain of rhinoceros hemoglobin contains glutamic acid at position beta 2, and important site for the binding of organic phosphates. We have investigated the oxygen binding properties of this hemoglobin and its interaction with ATP, 2,3-diphosphoglycerate, CO2 and chloride. The results show that the presence of GLU at position beta 2 nearly abolishes the effect of organic phosphates and CO2, whereas the oxygen-linked binding of chloride is not affected. Thus rhinoceros hemoglobin has only protons and chloride anions as major allosteric effectors for the control of its oxygen affinity. From the results obtained with hemoglobin solutions it can be calculated that the blood oxygen affinity of the rhinoceros must be rather high with a P50 of about 20 torr at pH 7.4 and 37 degrees C, which conforms with observations obtained for other large mammals.

Animals↗

PubMed1984

The amino-acid sequence of alpha A- and beta-chains from the major hemoglobin component of American flamingo (Phoenicopterus ruber ruber).

The complete amino-acid sequence of alpha A- and beta-chains from the major hemoglobin component (HbA) of American Flamingo ( Phoenicopterus ruber ruber) is presented. The minor component (HbD) with alpha D-chains was detected in similar amounts (25%) as in chicken and pheasant hemoglobins. The comparison of American Flamingo and Greylag Goose (Anser anser) hemoglobins shows that alpha A-chains differ by 22 exchanges and beta-chains by only 4 exchanges. Two substitutions modify alpha 1 beta 1-contacts. Amino-acid replacements between American Flamingo and other bird hemoglobins are discussed.

Amino Acid Sequence↗

PubMed1984

The primary structure of the hemoglobin of the mole rat (Spalax ehrenbergi, rodentia, chromosome species 60).

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.

Amino Acid Sequence↗