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Biomedical subjects

F Sakiyama

Publications and source records attributed to F Sakiyama.

At least 91 records · Page 5Linked to original sources

The single proline-glutamine substitution at position 5 enhances the potency of amyloid fibril formation of murine apo A-II.

The primary structure of murine apolipoprotein A-II (apo A-II) has been determined. Apo A-II consists of a single polypeptide chain of 78 amino acid residues, of which the amino-terminus is pyrrolidone carboxylic acid. Except for residues 5 and 38, the amino acid sequence is identical to that of murine senile amyloid protein (ASSAM), which has a common antigenicity with apo A-II. Substitution of glutamine (ASSAM) for proline (apo A-II) at position 5 is distinct and may possibly be related to murine senile amyloid-ogenesis.

Amino Acid Sequence↗

Characterization of structural unit of phospholamban by amino acid sequencing and electrophoretic analysis.

The partial amino acid sequence of phospholamban from canine cardiac sarcoplasmic reticulum was determined by sequence analysis of the peptides obtained from the protein cleaved by cyanogen bromide and with TPCK-trypsin. The sequence determined initiated with N alpha-acetylated methionine followed by 44 amino acid residues intervening two unidentified residues. This polypeptide would represent a structural unit (protomer) of phospholamban. Analysis of temperature-dependent conversion of phospholamban from 26 kDa to lower molecular weight form (6 kDa) suggested that phospholamban holoprotein is composed of five identical protomers.

Amino Acid Sequence↗

High homology is present in the primary structures between murine senile amyloid protein (ASSAM) and human apolipoprotein A-II.

The primary structure of a murine senile amyloid protein (ASSAM) was determined. The protein consists of a single polypeptide chain of 78 amino acid residues. The amino-terminus is blocked with pyrrolidone-carboxylic acid. The sequence differs from that of the known murine amyloid A protein and is highly homologous to human apolipoprotein (apo) A-II. The result indicates that the putative precursor of the senile amyloid protein is apo A-II in mice.

Amino Acid Sequence↗

Cadherin cell adhesion molecules with distinct binding specificities share a common structure.

Ca2+-dependent cell--cell adhesion molecules, termed cadherins, are divided into subclasses with distinct tissue distributions and distinct cell-binding specificities. To elucidate the biochemical relationship of these subclasses, we compared the pattern of tryptic cleavage and the partial amino acid sequence of mouse liver E-cadherin with those of chicken brain N-cadherin. Although these two cadherins are distinct in their cell-binding and immunological specificities, they showed an identical mol. wt and a similar tryptic cleavage pattern. We isolated tryptic fragments of E- and N-cadherin, and determined the sequences of nine amino acid residues of their amino terminus. The results showed that sequences of amino acids from the amino terminus to the 7th residues are identical in these two cadherins. We thus suggest that cadherins with distinct specificities have a common genic origin.

Animals↗

Nucleotide sequence of the lig gene and primary structure of DNA ligase of Escherichia coli.

The DNA ligase of Escherichia coli catalyses the NAD-dependent formation of phosphodiester linkages between 5'-phosphoryl and 3'-hydroxyl groups in DNA. It is essential for DNA replication and repair of damaged DNA strands. We determined the nucleotide sequence of the lig gene of Escherichia coli coding for DNA ligase and flanking regions. The coding frame of the gene was confirmed by the amino acid composition and the amino- and carboxyl-terminal amino acid sequences of the purified ligase. The ligase consists of 671 amino acid residues with a molecular weight of 73,690.

Amino Acid Sequence↗

Reexamination of the primary structure of an antitumor protein, neocarzinostatin.

The primary structure of an antitumor protein, neocarzinostatin, has been reinvestigated by conventional and gas-phase Edman degradation procedures. Sequence analyses of tryptic peptides of both S-carboxymethylated and S-aminoethylated derivatives as well as peptic peptides of the native protein revealed a revised primary structure of neocarzinostatin. The present sequence of 113 amino acid residues thus established agrees with results obtained by fast atom bombardment and gas chromatographic mass spectrometry which were published recently [B.N. Gibson, W.C. Herlihy, T.S.A. Samy, K.S. Hahm, H. Maeda, J. Meienhofer, and K. Biemann (1984) J. Biol. Chem. 259, 10801-10806]. The assignment of four intriguing asparagine/aspartic acid residues has been also achieved.

Amino Acid Sequence↗

Expression of the human salivary alpha-amylase gene in yeast and characterization of the secreted protein.

Recombinant plasmids were constructed in which the human salivary alpha-amylase gene, with or without the N-terminal signal sequence for secretion, was placed under control of the APase (PHO5) promoter of Saccharomyces cerevisiae. In yeast cells transformed with the alpha-amylase gene having the human signal sequence for secretion, the gene was expressed and the enzyme was secreted into the medium in three different glycosylated forms. The amylase gene without the signal sequence was also expressed in yeast, but the products were neither secreted nor glycosylated. Determination of the N-terminal amino acid (aa) sequence revealed that the 15-aa signal sequence had been cleaved from the secreted enzyme, and that the N-terminal residue, glutamine, had been modified into pyroglutamate, as is commonly observed with the mammalian salivary alpha-amylase. Thus, the human salivary alpha-amylase signal sequence for secretion was correctly recognized and processed by the yeast secretory pathway. The C-terminal residue was identified as leucine, which is predicted from the nucleotide sequence data to be located at position 511 in front of the termination codon. Therefore, there is no post-translational processing in formation of the C terminus.

Acid Phosphatase↗

Amino acid sequence of copper,zinc-superoxide dismutase from spinach leaves.

The complete amino acid sequence of Cu,Zn-superoxide dismutase (SOD) from spinach leaves has been determined on the basis of peptides obtained by cyanogen bromide (BrCN) cleavage and by enzymic hydrolyses with Achromobacter lyticus lysylendopeptidase, Staphylococcus aureus V8 protease, trypsin, and thermolysin. The spinach SOD consists of a total of 154 amino acid residues with alanine as the amino(N)-terminus and valine as the carboxy(C-)terminus. The present sequence, which has been established for the enzyme from a plant, is also highly homologous to those of the enzymes from other species. Especially, the residues essential for metal binding and enzyme activity have been extensively conserved among all of the Cu,Zn-SODs hitherto analyzed.

Acetylation↗

Complete amino acid sequence of bovine colostrum low-Mr cysteine proteinase inhibitor.

The complete amino acid sequence of bovine colostrum cysteine proteinase inhibitor was determined by sequencing native inhibitor and peptides obtained by cyanogen bromide degradation, Achromobacter lysylendopeptidase digestion and partial acid hydrolysis of reduced and S-carboxymethylated protein. Achromobacter peptidase digestion was successfully used to isolate two disulfide-containing peptides. The inhibitor consists of 112 amino acids with an Mr of 12787. Two disulfide bonds were established between Cys 66 and Cys 77 and between Cys 90 and Cys 110. A high degree of homology in the sequence was found between the colostrum inhibitor and human gamma-trace, human salivary acidic protein and chicken egg-white cystatin.

Amino Acid Sequence↗

Isocratic separation of PTH-amino acids at picomole level by reverse-phase HPLC in the presence of sodium dodecylsulfate.

The phenylthiohydantoin (PTH) derivatives of protein amino acids have been separated by reverse-phase high performance liquid chromatography (HPLC) on a fully end-capped C18 column using an isocratic solvent system. The developing solvent was 0.01 M sodium acetate buffer (pH 4.5) containing 39.5% acetonitrile and 0.02% sodium dodecylsulfate (SDS). With an automated liquid chromatography equipped with a dual-channel detector, operating at 254 and 313 nm, the present isocratic separation system was quite useful for routine microanalysis of PTH-amino acids released with a "gas-phase" sequencer. The time for one run was approximately 23 min and the limit of analysis approximately 2.5 pmol of a PTH-amino acid.

Amino Acids↗

Exposed tyrosine residues of lambda cro repressor protein evidenced by nitration and photo CIDNP experiments.

The tyrosine residues of lambda cro repressor were partially nitrated with tetranitromethane under mild conditions. After digestion by Achromobacter protease I, the extent of nitration was determined by HPLC and amino acid analysis. Tyr 26 was most easily nitrated and Tyr 51 followed it. Tyr 10 was resistant to nitration. By comparison of the proton magnetic resonance spectrum of the partially nitrated cro protein with the above result, the aromatic proton resonances of the tyrosine side chains could be assigned to individual tyrosine residues. The extent of nitration is parallel to the accessibility to a flavin dye as measured by photo CIDNP (chemically induced dynamic nuclear polarization).

Amino Acids↗

Amino acid sequence of calmodulin from wheat germ.

The complete amino acid sequence of calmodulin from wheat germ was determined by isolating and sequencing the cyanogen bromide and tryptic peptides. The protein consisted of 149 amino acid residues and its amino(N)-terminus was blocked with an acetyl group. Wheat germ calmodulin lacked tryptophan and contained 1 mol each of histidine, tyrosine, cysteine, and N epsilon-trimethyllysine residues per mol of the protein. A comparison of its amino acid sequence with that of bovine brain calmodulin indicated that there were eleven amino acid subsitutions other than amide assignments, two insertions and one deletion of amino acid residues in wheat germ calmodulin.

Amino Acid Sequence↗

Complete amino acid sequence of mouse prolactin.

The complete primary structure of mouse prolactin has been established on the basis of tryptic peptides from cyanogen-bromide-treated, S-carboxymethylated mouse prolactin and Staphylococcus-aureus-protease-cleaved overlaps, which were sequenced by manual liquid-phase and solid-phase Edman degradation. Three disulfide bonds were assigned to Cys-4-Cys-9, Cys-56-Cys-172, and Cys-189-Cys-197 by digestion of intact prolactin with S. aureus protease. One of the characteristics to date is replacement of Trp-89, which is commonly present among prolactin, growth hormone and choriomammotropin, by serine. It was suggested, by comparison with five other prolactins, five growth hormones and human choriomammotropin, that Asp-18, His-25, Ser-60 and Thr-63 are essential to lactogenic activity.

Amino Acid Sequence↗

Nucleotide sequence of the phoS gene, the structural gene for the phosphate-binding protein of Escherichia coli.

phoS is the structural gene for the phosphate-binding protein, which is localized in periplasm and involved in active transport of phosphate in Escherichia coli. It is also a negative regulatory gene for the pho regulon, and the gene expression is inducible by phosphate starvation. The complete nucleotide sequence of the phoS gene was determined by the method of Maxam and Gilbert (A. M. Maxam and W. Gilbert, Methods Enzymol. 65:499-560, 1980). The amino acid sequences at the amino termini of the pre-PhoS and PhoS proteins and at the carboxy terminus of the PhoS protein were determined by using the purified proteins. Furthermore, the amino acid sequence of enzymatically digested peptide fragments of the PhoS protein was determined. The combined data established the nucleotide sequence of the coding region and the amino acid sequence of the pre-PhoS and the PhoS proteins. The pre-PhoS protein contains an extension of peptide composed of 25 amino acid residues at the amino terminus of the PhoS protein, which has the general characteristics of a signal peptide. The mature PhoS protein is composed of 321 amino acid residues, with a calculated molecular weight of 34,422, and lacks the disulfide bond and methionine. The regulatory region of phoS contains a characteristic Shine-Dalgarno sequence at an appropriate position preceding the translational initiation site, as well as three possible Pribnow boxes and one -35 sequence. the nucleotide sequence of the regulatory region of phoS was compared with those of phoA and phoE, the genes constituting the pho regulon.

Amino Acid Sequence↗