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T Kleinschmidt

Publications and source records attributed to T Kleinschmidt.

At least 73 records · Page 4Linked to original sources
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

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↗
PubMed1984

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↗
PubMed1983

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↗
PubMed1983

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↗
PubMed1983

[The primary structure of hemoglobins of the rock hyrax (Procavia habessinica, Hyracoidea): insertion of glutamine in the alpha chains].

The chromatography of the hemoglobin of the rock hyrax (Procavia habessinica) gives two components (73% HbI and 27% HbII). The amino-acid analysis and the sequences of the globin chains elucidated with the phenylthiohydantoin method, did not show any differences between the alpha I and alpha II or beta I and beta II chains, respectively. The different chromatographical behaviour cannot be explained. After chain separation by chromatography on CM-52 cellulose, all four primary structures were elucidated automatically in a sequenator on the chains and the tryptic peptides. In 20% of the beta I chains the N-terminal valine was blocked by acetyl. The alignment was performed by homology with the chains of human adult hemoglobin. The alpha chain of the rock hyrax has 142 amino-acid residues, i.e. one residue more than normal mammalian alpha chains, caused by an insertion of glutamine in the GH region supposed between positions 115 and 116. A comparison of human and hyrax hemoglobins shows an exchange of 21 amino-acid residues in the alpha chains and of 24 in the beta chains. Some substitutions in alpha 1 beta 1 contacts and in the surrounding of the heme are not supposed to effect the function of the hemoglobin. The phylogenetic relationship between the rock hyrax and the Indian elephant (Elephas maximus) on the one hand and with some Perissodactyla on the other, is discussed. Up to now the exchanges of alpha 110(G17)Ala leads to Ser and beta 56(D7)Gly leads to His have only been found in hyrax and elephant. This indicates a certain relationship between Hyracoidea and Proboscidea.

Amino Acid Sequence↗
PubMed1983

[The primary structure of hemoglobins from the bottlenosed dolphin (Tursiops truncatus, Cetacea)].

Only one hemoglobin component was found in the bottlenosed dolphin (Tursiops truncatus, Cetacea). 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 und beta chains of adult human hemoglobin. A comparison of these two hemoglobins shows an exchange of 22 amino acid residues in the alpha chains and of 20 in the beta chains which corresponds to the phylogenetic distance between primates and cetacea. In the surroundings of the heme we found one substitution in the beta chains. In the alpha 1 beta 1 subunit interphase three and four residues are exchanged respectively in the alpha and beta chains. The possible influence of two exchanges in the alpha 1 beta 2 contact region (alpha 38 (C3) Thr leads to Ser and alpha 44 (CD2) Pro leads to Ser) on the oxygen affinity is discussed. Compared with hemoglobins of terrestrial mammals the primary structure of dolphin hemoglobin shows no amino acid substitutions, which alter the function of the molecule significantly. The adaptation to hypoxic conditions during diving is regulated by other mechanisms.

Amino Acid Sequence↗
PubMed1982

[Hemoglobins XLVI: the primary structure of the alpha-chain of armadillo (Dasypus novemcinctus, Edentata) hemoglobin (author's transl)].

The complete primary structure of the identical alpha-chains of the two hemoglobin components of armadillo (Dasypus novemcinctus) is presented. It was established on the tryptic peptides by automatic Edman degradation. The alignment was done according to the homology with human alpha-chains. 25 differences were found between both chains. A comparison of the functional amino acid residues shows one substitution in the surrounding of the heme, there in the alpha 1 beta 1 - and two in the alpha 1 beta 2 - subunit interface. The two replacements alpha 38(C3)Thr leads to Pro and alpha 44(CD) - Pro leads to Ser may contribute to the high oxygen affinity of the armadillo hemoglobin by destabilization of the T-structure.

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

[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↗
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, XLIII: The primary structure of mole hemoglobin (Talpa europaea) (author's transl)].

The hemoglobin of the european mole (Talpa europaea) has only one component. The alpha- and beta-chains were separated by chromatography on CM 52 cellulose. The primary structures of both chains were mainly established on the tryptic peptides by automatic Edman degradation. The N-terminal regions were sequenced on the chains. Large C-terminal peptides could be isolated and sequenced after acidic hydrolysis of the Asp-Pro bond (alpha: 94/95, beta: 99/100). The peptides were aligned by their homology with human alpha- and beta-chains. A comparison with human hemoglobin shows an exchange of 18 amino acid residues in the alpha-chains and of 30 in the beta-chains. The substitutions in the surroundings of the heme and the contacts between the subunits are discussed. All amino acid residues responsible for the binding of 2,3-dihosphoglycerate are present. Nevertheless a high oxygen affinity and a reduced interaction with diphosphoglycerate are found in mole hemoglobin (Jelkmann, W., Oberthür, W., Kleinschmidt, T. & Braunitzer, G. (1981) Respir. Physiol., in press). According to the sequence a relaxed structure of the central cavity between the beta-chains can be the reason for the low interaction between phosphate and protein. The oxygen affinity is not only affected by the presence of diphosphoglycerate-binding sites in hemoglobin but also by the structure in this region of the molecule.

Amino Acid Sequence↗
PubMed1980

[Hemoglobin, XXXI. Analysis or the primary structure of the monomeric hemoglobin CTT I (erythrocruorin) of Chironomus thummi thummi, Diptera].

The sequence analysis of the monomeric hemoglobin CTT I (erythrocruorin) of Chironomus thummi thummi is given. The tryptic peptides were separated and sequenced by automatic Edman degradation. The alignment was established with help of some peptic peptides. In CTT I two polypeptide chains are present. They differ in position 98, where we found alanine and threonine in the ratio 1:1. CTT I is compared with human myoglobin and the monomeric component CTT III. The dimeric components of CTT are also included into the discussion, because CTT I seems to have an enlarged heme pocket like them. We particularly compare the amino acid residues involved in the heme contacts. The lack of a Bohr effect is discussed.

Amino Acid Sequence↗
PubMed1980

[Hemoglobins, XXXII. Analysis of the primary structure of the monomeric hemoglobin CTT VIIA (erythrocruorin) or Chironomus thummi thummi, Diptera (author's transl)].

The dimeric hemoglobin CTT VIIA (erythrocruorin) was isolated from the hemolymph of the larva from Chironomus thummi thummi and purified by preparative polyacrylamide gel electrophoresis. Peptides obtained by limited tryptical digestion were sequenced by automatic Edman degradation. For the elucidation of the sequence in the C-terminal region of the chain, additional cleavages with proteinase of Staphylococcus aureus and chymotrypsin were necessary. CTT VIIA is compared with human beta-chains and other hemoglobins of Chironomus. The amino acid residues in the pocket are especially discussed. Most of them are invariant in all Chironomus hemoglobins, independent of the size of the heme pocket, which is normal in some components and enlarged in others.

Amino Acid Sequence↗