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Biomedical subjects

H Matsubara

Publications and source records attributed to H Matsubara.

At least 415 records · Page 23Linked to original sources
PubMed1981

Regulation of SOS functions: purification of E. coli LexA protein and determination of its specific site cleaved by the RecA protein.

The LexA protein of Escherichia coli was purified to more than 96% purity from cells harboring a recombinant plasmid carrying the lexA gene with the lacZ promoter sequence. The amino acid composition of the LexA protein and its amino-terminal sequence were analyzed. The results are in agreement with the prediction from the nucleotide sequence of the lexA gene. The LexA protein is cleaved into two polypeptides by E. coli RecA protein in the presence of ATP and single-stranded DNA. The site of the specific cleavage was determined by analyzing amino acid sequences of the cleaved products at the amino and carboxyl termini. The cleavage of the LexA protein by the RecA protein was found to occur at a single site between Ala84 and Gly85.

Bacterial Proteins↗
PubMed1981

Ferredoxin excreted from photosynthetic bacterium, Rhodospirillum rubrum: purification and properties.

When the photoheterotroph, Rhodospirillum rubrum, was grown in the light, ferredoxin was excreted from the cells in a significant amount, as well as hydrogenase. The extracellular ferredoxin was purified to a homogeneous state. The molecular weight was approximately 9,000, and the oxidation-reduction mid-potential was -0.29 V (N=1) at pH 7.0 and 25 degrees C. The amino acid composition was different from those of the intracellular ferredoxins, which were already known. The contents of non-heme iron and acid-labile sulfur were 10.6 and 7.9 mol/mol protein, respectively. The extracellular hydrogenase catalyzed the evolution of hydrogen gas from the ferredoxin in the reduced form. The Km for the ferredoxin was 4.1 micro M, one-seven hundredth as low as that for methyl viologen. There is a possibility that hydrogenase here were functional for evolution of hydrogen gas outside the cells.

Amino Acids↗
PubMed1981

Correspondence of the larger subunit of the MoFe-protein in clostridial nitrogenase to the nif D gene products of other N2-fixing organisms.

The amino(N)-terminal sequence of the larger subunit (alpha) of the MoFe-protein from Clostridium pasteurianum was determined up to 179 amino acid residues by analyses of BrCN and tryptic peptides of the original subunit. Apparent similarities exist among the sequence of the clostridial alpha-subunit, that of the smaller subunit (beta) of the Azotobacter vinelandii MoFe protein, and those predicted from the nucleotide sequences of nif D genes in Klebsiella pneumoniae and Anabaena 7120. In comparing the sequences of C. pasteurianum and K. pneumoniae, 45% of residues are identical of a total of 184 sites. Therefore, the larger subunit of the clostridial MoFe-protein must correspond to the nif D gene product of K. pneumoniae.

Amino Acid Sequence↗
PubMed1981

Amino acid sequence of an intrinsic inhibitor of mitochondrial ATPase from yeast.

The amino acid sequence of an intrinsic inhibitor of mitochondrial ATPase isolated from yeast was completed by using solid-phase sequencing and conventional procedures. The inhibitor was found to be composed of 63 amino acid residues, to lack tryptophan, cysteine, and tyrosine, and to have a molecular weight of about 7,383. The inhibitor was characterized as a basic protein with 16 basic and 13 acidic amino acid residues, and several clusters of basic residues were noted. Some comments are made on the hydrophobic amino acids and the presence of repeated sequences.

Adenosine Triphosphatases↗
PubMed1981

Studies on algal cytochromes. III. Amino acid sequence of cytochrome c-553 from a brown alga, Petalonia fascia.

The amino acid sequence of a photosynthetic cytochrome c-553 isolated from a brown alga, Petalonia fascia was determined by BrCN fragmentation and a solid phase Edman degradation. The cytochrome contains 85 amino acid residues, giving a molecular weight of 9,803. The complete amino acid sequence is as follows: Val-Asp-Ile-Asn-Asn-Gly-Glu-Ser-Val-Phe-Thr-Ala-Asn-Cys-Ser-Ala-Cys-His-Ala-Gly -Gly-Asn-Asn-Val-Ile-Met-Pro-Glu-Lys-Thr-Leu-Lys-Lys-Asp-Ala-Leu-Glu-Glu-Asn-Gl u-Met-Asn-Asn-Ile-Lys-Ser-Ile-Thr-Tyr-Gln-Val-Thr-Asn-Gly-Lys-Asn-Ala-Met-Pro-A la-Phe-Gly-Gly-Arg-Leu-Ser-Glu-Thr-Asp-Ile-Glu-Asp-Val-Ala-Asn-Phe-Val-Ile-Ser-Gln-Ser-Gln-Lys-Gly-Trp. The highest homology was found between the sequences of cytochromes c-553 of P. fascia and Alaria esculenta, the next between those of P. fascia and Porphyria tenera.

Amino Acid Sequence↗
PubMed1981

The complete amino acid sequence of parsley (Petroserinum sativum) ferrodoxin.

The amino acid sequence of a ferredoxin from parsley (Petroserinum sativum) was determined by various conventional methods. Five tryptic peptides of carboxymethylated(Cm)-ferrodoxin were sequenced by a combination of automatic solid-phase and manual Edman degradations. The amino(N)-terminal sequences of Cm-ferrodoxin and its carboxy(C)-terminal half produced by tryptic cleavage specifically at the sole arginine residue of the molecule overlapped the five tryptic peptides. The molecule consists of 96 amino acid residues, including 5 cysteines, and lacks tryptophan. Parsley ferredoxin shows the greatest homology to wheat ferredoxin among other green plant ferredoxins.

Amino Acid Sequence↗
PubMed1981

X-ray analysis of a [2Fe-2S] ferrodoxin from Spirulina platensis. Main chain fold and location of side chains at 2.5 A resolution.

A [2Fe-2S] ferrodoxin from Spirulina platensis crystallized in space group C2221 with cell dimensions of a = 62.32, b = 28.51, c = 108.08 A, and alpha = beta = gamma = 90.0 degrees. X-ray structure analysis of the protein was carried out at 2.5 A resolution by the single isomorphous replacement method coupled with the derivative and the native anomalous dispersion methods. Phase angles of 2182 independent reflections were determined and their average figure of merit was 0.58. Each of 98 residues was superposed on the electron density sections enlarged to 2 cm/l A with a half-mirror device (Richards box). About 25% of the total residues form beta-structure and 10% fold in a tow-turn alpha-helix. A beta-barrel-like structure was found in the main chain fold. A polypeptide segment from residues 41 to 49 forms a loop structure outside the barrel. Two iron atoms of the [2Fe-2S] cluster are coordinated by three cysteines in the loop and by Cys-79. Hydrogen bonds of NH....S and OH....S stabilize the loop conformation. Most side chains are reasonably oriented in the molecule. The internal volume of the barrel is occupied by aliphatic nonpolar residues. All the charged groups are accessible to solvent molecules.

Binding Sites↗
PubMed1981

The second ferredoxin from spinach leaves.

A minor component of ferredoxin (about 20% of the total content) was separated from the major one on a DEAE Trisacryl M column only after carboxymethylation of the ferredoxin purified from spinach leaves by the conventional procedure. The amino acid compositions and terminal sequences of the two revealed that the major component corresponded to the one previously sequenced (Matsubara, H. & Sasaki, M. (1968) J. Biol. Chem. 243, 1732-1757) and the minor one had a completely different structure from that of the major one. Comparison of the amino(N)-terminal 34 residues showed 11 amino acid substitutions between the two components. Thus the existence of a second ferredoxin was demonstrated in spinach leaves.

Amino Acid Sequence↗
PubMed1980

Structural basis for the difference of the regulatory properties between potato and rabbit muscle phosphrylases. The NH2-terminal sequence of the potato enzyme.

alpha-Glucan phosphorylases (EC 2.4.1.1) from potato tuber and rabbit muscle are similar in some of the structural and kinetic properties, despite the difference in the regulation of enzyme activity. The NH2-terminal region in the rabbit muscle enzyme is important for both allosteric and covalent controls. In this paper, the NH2-terminal 104-residue sequence of the potato enzyme was determined to compare it with that of the rabbit muscle enzyme. Edman degradations of the whole protein revealed the terminal sequence of Thr-Leu-X-Glu-X-X-His-His-. Using this sequence as a marker, the NH2-terminal 81-residue peptide was isolated from the CNBr-treated protein and sequenced. The sequence of this peptide was extended further by the 23-residue sequence of the other two CNBr peptides by considering the sequence similarity between the potato and rabbit muscle enzymes. The combined results of the present and previous studies (Nakano, K., Wakabayashi, S., Hase, T., Matsubara, H. and Fukui, T. (1978) J. Biochem. (Tokyo) 83, 1085-1094 and Nakano, K., Fukui, T., and Matsubara, H. (1980) J. Biochem. (Tokyo) 87, 919-927) indicate that the potato and rabbit muscle enzymes are highly homologous except for the NH2-terminal 33-residue region which is very different. The potato enzyme has 2 more residues attached to the NH2-terminal region. The remarkable dissimilarity in the structure of this region provides a basis for the difference of the regulatory properties between the two enzymes. It is conceivable that phosphorylases existed originally as a large catalytically active molecule, and that the regulatory mechanism was then formed within the molecule during the course of evolution.

Amino Acid Sequence↗
PubMed1980

Amino acid sequence of 2Fe-2S ferredoxin from an extreme halophile, Halobacterium of the Dead Sea.

The primary structure of the 2Fe-2S ferredoxin from Halobacterium of the Dead Sea was determined and it consisted of 128 amino acid residues including an N epsilon-acetyllysyl residue. Due to a high degree of sequence homology between this ferredoxin and the one from Halobacterium halobium, all tryptic peptides could be aligned in order. Only 20 amino acid differences were observed between these two halobacterial ferredoxins. The distribution of cysteinyl residues involved in the iron chelation was similar to that of chloroplast-type ferredoxins.

Amino Acid Sequence↗
PubMed1980

Amino acid sequences of two ferredoxins from Phytolacca esculenta. Gene duplication and speciation .

The amino acid sequences of two ferredoxins from Phytolacca esculenta were determined by a combination of solid-phase sequencing and the conventional methods. Ferredoxins I and II were composed of 96 and 98 amino acid residues, respectively, and ferredoxin I showed sequence heterogeneity at two positions. The amino acid sequences of ferredoxins I and II from Phytolacca esculenta were very similar to those of corresponding ferredoxins I and II from Phytolacca americana. Amino acid differences among Phytolacca ferredoxins and other higher plant ferredoxins suggest that duplication of the ferredoxin gene occurred after the divergence of Phytolacca from other higher plants and preceded the separation of two species of Phytolacca.

Amino Acid Sequence↗
PubMed1980

Amino acid sequence of a purothionin homolog from barley flour.

A purothionin homolog was isolated from barley flour and purified by CM-52 column chromatography. It showed potent lethal activity towards brewer's yeast and its complete amino acid sequence was determined to be as follows. Lys-Ser-Cys-Cys-Arg-Ser-Thr-Leu-Gly-Arg-Asn-Cys-Tyr-Asn-Leu-Cys-Arg-Val-Arg-Gly-Ala-Gln-Lys-Leu-Cys-Ala-Gly-Val-Cys-Arg-Cys-Lys-Leu-Thr-Ser-Ser-Gly-Lys-Cys-Pro-Thr-Gly-Phe-Pro-Lys. It thus consists of 45 amino acid residues with 8 cysteines. The number of amino acid residues and the positions of the 8 cysteines are identical with those of wheat purothionins. There is a high degree of homology in the primary structures of these proteins.

Amino Acid Sequence↗