Biomedical subjects

T Kleinschmidt

Publications and source records attributed to T Kleinschmidt.

At least 19 recordsLinked to original sources

PubMed1992

The primary structure of the hemoglobin from the tomb bat (Taphozous georgianus, Microchiroptera).

The primary structures of the alpha- and beta-chains of the single hemoglobin component from the tomb bat (Taphozous georgianus, Microchiroptera) are presented. After chain separation by reversed-phase HPLC the sequences could be determined by automatic gas and liquid phase Edman degradation of the chains and their tryptic peptides. The alpha- and beta-chains differ from human hemoglobin by 14 and 18 replacements, respectively. Compared to the total number of amino-acid exchanges, the exchange rate in the interhelical regions of the alpha-chains is surprisingly high (25%). It seems unlikely that substitutions at contact positions affect the oxygen binding properties of the hemoglobin.

Amino Acid Sequence↗

PubMed1991

Close tetrapod relationships of the coelacanth Latimeria indicated by haemoglobin sequences.

The origin of tetrapods has been debated for many years. In traditional systematics, the extinct lobe-finned bony fish (Rhipidistia) are regarded as the closest relatives of tetrapods. Among living fish, the coelacanth Latimeria chalumnae (Actinistia), which is the only recent representative of the Crossopterygii (Actinistia and Rhipidistia), the lungfish (Dipnoi) and ray-finned fish (Actinopterygii), have each been considered as sister-groups of the tetrapods. We have now determined the sequence of the alpha- and beta-globin chains of coelacanth haemoglobin and compared them with all known haemoglobins of bony and cartilaginous fish as well as those of tadpoles and adult amphibians. Haemoglobins of bony fish match more closely those of larval than adult amphibians. The beta chains of Latimeria match those of tadpoles more closely (54%) than do those of any other fish, whereas the alpha chains of Latimeria (45.4%), and especially of teleosts (49.2%), are closer to those of larval amphibians than are those of lungfish (39.8%). If only synapomorphous sequence matches (those at derived positions shared by one bony fish and tadpoles but not by any other bony fish) are considered, both Latimeria globin chains have distinctly more identities with phase of tadpoles than do those of any bony fish. Thus the primary structure of Latimeria haemoglobin indicates that the coelacanth is the closest living relative of tetrapods.

Amino Acid Sequence↗

PubMed1991

The primary structure of the hemoglobin from the aardwolf (Proteles cristatus, Hyaenidae).

The hemoglobin of the aardwolf (Proteles cristatus) contains only one component. In this paper, we are presenting its primary structure. 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- as well as the beta-chains show 20 exchanges compared with the corresponding human chains. The difference to the masked palm civet (Paguma larvata) and the spotted hyaena (Crocuta crocuta) is marked by 16 and 4 replacements in the alpha-chains and by 10 and 1 in the beta-chains, thus supporting the hyaenid character of the aardwolf. The exchanges at contact positions are shared by other carnivoran hemoglobins.

Amino Acid Sequence↗

PubMed1991

The primary structure of the hemoglobin from the Australian ghost bat (Macroderma gigas, Microchiroptera).

The Australian ghost bat (Macroderma gigas, Microchiroptera) has two hemoglobin components in the ratio 3:2. They share identical beta-chains and differ by three replacements in the alpha-chains. The primary structures of all three chains are presented. They could be separated by high-performance liquid chromatography. The sequences were determined by automatic liquid and gas phase Edman degradation of the chains and their tryptic peptides. The two alpha-chains show 18 and 19 and the beta-chains 15 exchanges compared to human alpha- and beta-chains, respectively. The divergent evolution of Macroderma gigas and Megaderma lyra, two representatives of the family Megadermatidae, is discussed. An influence of replacements at functionally important positions on the hemoglobin oxygen affinity seems unlikely.

Adult↗

PubMed1991

A "living fossil" sequence: primary structure of the coelacanth (Latimeria chalumnae) hemoglobin--evolutionary and functional aspects.

The coelacanth (Latimeria chalumnae, Actinistia) has a single hemoglobin component. The primary structures of the alpha- and beta-chains are presented. They could be separated by reversed-phase HPLC. Peptides obtained by tryptic digestion of the native and oxidized chains were isolated by reversed-phase HPLC and sequenced in liquid and gas-phase sequenators. The alignment was achieved by employing the N-terminal sequences of the native chains and those of a beta-chain cyanogen bromide peptide as well as fragments obtained by acid hydrolysis. The Latimeria alpha-chains consist of 142 amino-acid residues, due to a fish-specific insertion between positions 46 and 47, whereas the beta-chains are of normal length (146 residues). Latimeria alpha- and beta-chains share 72 (51.1%) and 70 (47.9%) identical residues with human hemoglobin, respectively. Numerous heme contacts and positions involved in subunit interface contacts are replaced. The most interesting of them were studied by molecular modeling. The loss of an alpha 1/beta 2-contact by the exchanges alpha 92(FG4)Arg----Leu and beta 43(CD2)Glu----Lys might be responsible for the easy dissociation of the tetrameric hemoglobin molecule. A comparison of the residues replaced in contact positions with fishes and amphibians revealed the highest number of matches between Latimeria and tadpoles. The same result was obtained by the evaluation of other regions relevant for structure and function of the molecule, like exon-intron boundary regions, phosphate binding sites and salt bridges responsible for the Bohr effect.

Amino Acid Sequence↗

PubMed1991

Primary structure and oxygen-binding properties of the hemoglobin from the lesser hedgehog tenrec (Echinops telfairi, Zalambdodonta). Evidence for phylogenetic isolation.

The primary structures of the alpha- and beta-hemoglobin chains of the lesser hedgehog tenrec (Echinops telfairi, Zalambdodonta) are presented. Chain separation was performed by carboxymethyl-cellulose chromatography. The peptides, obtained by tryptic digestion of the oxidized chains, were prefractionated by gel chromatography and isolated by reversed-phase HPLC. For sequence analysis gas and liquid phase sequencers were employed. The tenrec hemoglobin consists of one alpha- and two beta-chains the latter occurring in a 1:1 ratio and differing in beta 16 Gly/Cys and beta 118 Phe/Leu. Two external cysteine residues at beta 16 and beta 52 cause reversible polymerization to octamers and most likely irreversible formation of higher polymers. A comparison of the whole chains and certain positions of tenrec hemoglobin with those of Insectivora sensu strictu, Scandentia and Proto- and Metatheria corroborates a long and independent evolution of tenrec and its phylogenetic isolation from the Insectivora s.str. (hedgehog, musk shrew and mole). Replacements at positions involved in heme and subunit interface contacts are discussed. Compared to human hemoglobin the tenrec pigment shows a low intrinsic oxygen affinity as well as lower chloride and temperature sensitivities, a reduced Bohr effect and a strong response to 2,3-DPG. The possible adaptive significance of these properties is discussed in relation to the large diurnal body temperature variations seen in tenrecs.

Amino Acid Sequence↗

PubMed1990

Primary structure of a zinc protease from Bacillus mesentericus strain 76.

The amino acid sequence of the neutral zinc protease from Bacillus mesentericus strain 76 (MCP 76) has been determined by using peptides derived from digests with trypsin, chymotrypsin, and cyanogen bromide and from cleavage with o-iodosobenzoic acid. The peptides were purified by means of gel filtration and reversed-phase high-performance liquid chromatography and analyzed by automatic sequencing. The protein contains 300 amino acid residues. It proved to be identical with the neutral protease deduced from the DNA precursor sequence of Bacillus subtilis. The residues for zinc and substrate binding are conserved, whereas the number of calcium binding sites is reduced compared to thermolysin. A classification of the neutral zinc protease is discussed.

Amino Acid Sequence↗

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 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

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

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

Proteolytic specificity of the neutral zinc proteinase from Bacillus mesentericus strain 76 determined by digestion of an alpha-globin chain.

The proteolytic specificity of the neutral zinc proteinase from Bacillus mesentericus strain 76 (MCP 76)/Bacillus subtilis was determined by using the alpha-chain of walrus hemoglobin as substrate. The resulting peptides were fractionated by gel filtration and than isolated by reversed-phase HPLC. The peptides were identified on the basis of their amino-acid compositions and aligned with the known sequence of the walrus alpha-chain. The proteolytic specificity of MCP 76, deduced from the experimental cleavage pattern is compared to that of thermolysin. The amino-acid residues in positions P1 and P'1 on both sides of the scissible bond are considered as most important for the cleavage. MCP 76 prefers leucine, valine, phenylalanine and threonine in position P'1 as well as lysine, threonine, leucine and alanine in position P1 and thus differs from thermolysin which shows no preference for threonine in P'1 and accepts numerous amino-acid residues of different type in P1.

Amino Acid Sequence↗

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

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↗

PubMed1988

Oxygen binding properties, capillary densities and heart weights in high altitude camelids.

The oxygen binding properties of the blood of the camelid species vicuna, llama, alpaca and dromedary camel were measured and evaluated with respect to interspecific differences. The highest blood oxygen affinity, not only among camelids but of all mammals investigated so far, was found in the vicuna (P50 = 17.6 Torr compared to 20.3-21.6 Torr in the other species). Low hematocrits (23-34%) and small red blood cells (21-30 microns 3) are common features of all camelids, but the lowest values are found in the Lama species. Capillary densities were determined in heart and soleus muscle of vicuna and llama. Again, the vicuna shows exceptional values (3720 cap/mm2 on average in the heart) for a mammal of this body size. Finally, heart weight as percent of body weight is higher in the vicuna (0.7-0.9%) than in the other camelids studied (0.5-0.7%). The possibility that these parameters, measured in New World tylopodes at sea level, are not likely to change considerably with transfer to high altitude, is discussed. In the vicuna, a unique combination of the following features seems to be responsible for an outstanding physical capability at high altitude: saturation of blood with oxygen in the lung is favored by a high blood oxygen affinity, oxygen supply being facilitated by low diffusion distances in the muscle tissue. Loading, as well as unloading, of oxygen is improved by a relatively high oxygen transfer conductance of the red blood cells, which is due to their small size and which compensates the negative effect of a low hematocrit on the oxygen conductance of blood.(ABSTRACT TRUNCATED AT 250 WORDS)

2,3-Diphosphoglycerate↗