PubMed Health⌕ Search

Biomedical subjects

F Inagaki

Publications and source records attributed to F Inagaki.

At least 109 records · Page 6Linked to original sources
PubMed1990

Ceramide dihexosides from the spermatozoa of the starfish, Asterias amurensis, consist of gentiobiosyl- cellobiosyl-, and lactosylceramide.

Ceramide dihexoside was obtained from the spermatozoa of the starfish, Asterias amurensis. Gas-liquid chromatography of the methanolysate to determine the sugar composition of the lipid demonstrated an unequal ratio of glucose and galactose, implying that two or more glycolipids are present. They were separated by thin-layer chromatography on a borate-impregnated plate into two bands. From the results of methylation analysis and chromic acid oxidation, one was determined to be lactosylceramide, while the other was suggested to be a mixture of two diglucosylceramides: gentiobiosylceramide (Glc beta 1-6Glc beta 1-1Cer) and cellobiosylceramide (Glc beta 1-4Glc beta 1-1Cer). The molar ratio of gentiobiosyl-, cellobiosyl-, and lactosylceramide was estimated to be 0.7 : 0.3 : 1.0. Ceramide dihexosides obtained from another batch of the spermatozoa, collected at the same place in a different year, consisted almost exclusively of gentiobiosylceramide as confirmed by proton-nuclear magnetic resonance spectroscopy and fast-atom bombardment mass-spectrometry. The fatty acid compositions of these glycolipids were similar and the main acids were 14h:0, 15h:0, 16h:0, 18h:0, and 24h:1 (constituting more than 80% of the total acids). The long-chain base compositions were qualitatively similar and the major constituents were commonly d18:2, d18:3, d19:3, d22:2, and t22:1. Lactosylceramide was rich in t22:1, while diglucosylceramides were rich in d22:2.

Animals↗
PubMed1990

A unique fucoganglioside with blood group B determinant in rat spleen.

A unique fucoganglioside was isolated from rat spleen and characterized by compositional analysis, methylation analysis, exoglycosidase treatment, negative ion fast atom bombardment (FAB) mass spectrometry, and proton NMR spectrometry. The ganglioside was identified as alpha Gal,Fuc-GM1(NeuGc), which has the blood group B determinant at the nonreducing termini, as shown below: (formula; see text) This is the first report describing the occurrence in nature of alpha Gal,Fuc-GM1 containing N-glycolylneuraminic acid.

ABO Blood-Group System↗
PubMed1990

Three-dimensional structures of proteins determined by two-dimensional NMR and distance geometry calculations.

Due to the recent development of NMR spectroscopy, the three-dimensional structures of proteins up to 10 Kd in aqueous solution can be determined in atomic levels. In the present article, we show the intuitive description on the theoretical background of structural determination by NMR, where we take erabutoxin b as an example and compare the structures in aqueous solution and in the crystalline state. Then, we show the three-dimensional structure of mouse epidermal growth factor and human transforming growth factor alpha determined by NMR. On the basis of the results, we discuss the molecular mechanism of recognition between the epidermal growth factor and its receptor.

Crystallization↗
PubMed1990

Deletion of D-helix in bovine pancreatic phospholipase A2.

D-Helix-deleted bovine pancreatic phospholipase A2 was designed using molecular mechanic calculations, and synthesized. Effects of the deletion on the enzymatic activity and on the structure were investigated. The enzymatic activity of the mutant protein was about 40% of that of the native one for a micellar substrate of 1,2-dioctanoyl-phosphatidylcholine. Although the Michaelis constant of the mutant enzyme was not changed, the catalytic constant was decreased. The dissociation constant of calcium ion was also changed. 1H NMR study revealed a slight conformation change around the active site of the mutant enzyme in addition to changes around the mutated region. The effect on the activity of the mutation seems to be due to the conformational changes around the active site.

Amino Acid Sequence↗
PubMed1989

Characterization of two glucuronic acid-containing glycosphingolipids in larvae of the green-bottle fly, Lucilia caesar.

Two glucuronic acid-containing glycosphingolipids were purified from larvae of the green-bottle fly, Lucilia caesar by DEAE-Sephadex and Iatrobeads column chromatography. Structures of these acidic glycolipids, glycolipids X and Y, were elucidated by means of sugar analysis, permethylation, enzymatic hydrolysis, negative-ion fast atom bombardment mass spectrometry, and NMR studies. Glycolipid X was determined to have the following structure: GlcA beta 1-3Gal beta 1-3GalNAc alpha 1-4 GalNAc beta 1-4 GlcNAc beta 1-3Man beta 1-4Glc beta 1-1 ceramide. The other acidic glycolipid, glycolipid Y contains a phosphoethanolamine residue linked through the 6-hydroxy group of the N-acetyl-glucosamine unit of glycolipid X. The ceramide moieties were composed of saturated fatty acids (16:0-22:0) and tetradeca- and hexadeca-4-sphingenines. Based on the structural similarity of the ceramide moieties it appears likely that glycolipid X is an intermediate from which glycolipid Y is synthesized by addition of a phosphoethanolamine residue.

Animals↗
PubMed1989

Neutralizing monoclonal antibody specific for alpha-bungarotoxin: preparation and characterization of the antibody, and localization of antigenic region of alpha-bungarotoxin.

We prepared an alpha-bungarotoxin-specific monoclonal antibody that neutralizes the biological activity of the toxin in vivo. The antigenic determinant combining specifically with this antibody was determined on the basis of cross-reaction experiments using three other long neurotoxins and peptide fragments of alpha-bungarotoxin. The antigenic determinant was located on the peptide fragment containing S34-S35-R36-G37-K38, which forms a part of the expected site that binds to the acetylcholine receptor proteins.

Amino Acid Sequence↗
PubMed1989

Polypeptide chain fold of human transforming growth factor alpha analogous to those of mouse and human epidermal growth factors as studied by two-dimensional 1H NMR.

The 1H NMR spectrum of human transforming growth factor alpha (TGF-alpha) was analyzed almost completely by the sequential assignment method using two-dimensional NMR techniques. On the basis of the nearly complete sequence-specific resonance assignment, secondary and tertiary structures of human TGF-alpha in solution (pH 4.9, 28 degrees C) were determined to satisfy the upper limits of proton-proton distances derived from nuclear Overhauser effect experiments. Although human TGF-alpha and mouse epidermal growth factor (EGF) share 27% homology in amino acid sequence, the backbone chain folds in the two growth factors are quite similar. The structure and function of TGF-alpha is well characterized by the "mitten model" previously proposed for mouse EGF. The gross shape of the TGF-alpha molecule resembles a mitten. TGF-alpha interacts with the receptor as a mitten would grasp an object. However, there is an appreciable structural difference between the two growth factors in the back of the mitten that is formed by the N-terminal polypeptide segment. This is consistent with the evidence that the backs of these molecules are not involved in the receptor binding.

Amino Acid Sequence↗
PubMed1989

Accumulation of unique globo-series glycolipids in PC 12h pheochromocytoma cells.

In a previous paper, we reported the presence of a unique globo-series glycolipid as one of the major neutral glycolipid: Gal alpha 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-1' Cer, in the subcloned PC 12h pheochromocytoma cells (Ariga, T., Yu, R. K., Scarsdale, J. N., Suzuki, M., Kuroda, Y., Kitagawa, H., and Miyatake, T. (1988) Biochemistry 27, 5335-5340). Recently we found that the subcloned PC 12h cells accumulated other unusual neutral glycolipids. In order to characterize these glycolipids, PC 12h cells were subcutaneously transplanted into rats. The induced tumor tissue accumulated four minor neutral glycolipids, which were purified by droplet counter-current, Iatrobeads column, and preparative thin-layer chromatographies. These glycolipid structures were determined by fast atom bombardment-mass spectrometry, proton nuclear magnetic resonance spectroscopy, permethylation study, and sequential degradation with various exoglycosidases to be as follows: A, Fuc alpha 1-2Gal alpha 1-3Gal alpha 1- 4Gal beta 1-4Glc beta 1-1'Cer; B, GalNAc beta 1-3Gal alpha 1-3Gal alpha 1- 4Gal beta 1-4Glc beta 1-1'Cer; C, Gal alpha 1-3Gal alpha 1-3Gal alpha 1- 4Gal beta 1-4Glc beta 1-1'Cer; and D, Gal alpha 1-3Gal alpha 1-3Gal alpha 1- 3Gal alpha 1-4Gal beta 1-4Glc beta 1-1'Cer. Glycolipids A and B were tentatively characterized in normal rat small intestine (Breimer, M. E., Hansson, G. C., Karlsson, K.-A., and Leffler, H. (1982) J. Biol. Chem. 257, 557-568; Angstrom, J., Breimer, M. E., Falk, K.-E., Hansson, G. C., Karlsson, K.-A., and Leffler, H. (1982) J. Biol. Chem. 257, 682-688). Glycolipids C and D have not been reported in the literature.

Adrenal Gland Neoplasms↗
PubMed1989

Proton nuclear magnetic resonance study of the solution conformation of C3a-Arg69, a 69-residue N-terminal fragment of the third component of complement.

A proton nuclear magnetic resonance (NMR) study is reported of human C3a-Arg69, which is a 69-residue fragment obtained by the tryptic cleavage of human C3. It has been shown that the combined use of a CPase/digestion difference spectroscopy method (Endo and Arata (1985) Biochemistry 24, 1561-1568) with a variety of two-dimensional NMR techniques is effective in advancing spectral assignments for structural analyses. On the basis of the results of the NMR measurements, we have concluded that: 1) the N-terminal region of the C3a molecule plays a crucial role in stabilizing the conformation of the C-terminal segment Leu63-Arg69 and 2) the existence of the core region, which is formed by segment Tyr15-Tyr59 (Huber et al. (1980) Hoppe Seyler's Z. Physiol. Chem. 361, 1389-1399), is essential in maintaining this conformation. We also suggest that the disorder of the N-terminal region, which is invisible by the X-ray crystallographic study, is due to dimerization of this molecule in the crystal.

Amino Acid Sequence↗
PubMed1989

Structure determination of glucosyl beta 1-N-(omega-O-linoleoyl)-acylsphingosines of human epidermis.

Human epidermis gave two glycolipid bands that migrated faster than glucosylceramide and two bands that migrated like glucosylceramide and galactosylceramide, respectively, on TLC. The two faster migrating glycolipids (GL-I and GL-II), which exhibited alkalilability, were purified by conventional DEAE and silica gel column chromatographies, and further by HPLC on a silica gel column. Structure determination of the two components, named GL-I3 and GL-II3, which were finally purified from GL-I and GL-II, respectively, by HPLC on a reversed phase column, was performed by means of 1H-NMR spectroscopy, fast atom bombardment mass spectrometry, and component analysis involving GLC-mass spectrometry. GL-I3 was determined to be a mixture of glucosyl beta 1-N-(omega-O-linoleoyl)-triacontanoyl- and -dotriacontamonoenoyl-eicosasphingenine, and one of the two components of GL-II3 was determined to be glucosyl beta 1-N-(omega-O-linoleoyl)triacontanoyl-trihydroxyeicosasphingenin e. GL-I3 and GL-II3 were the major components of GL-I and GL-II, respectively, and both the latter contained additional four components, which were heterogeneous as to the ceramide portion. This paper reports the structures of acylglucosylceramides isolated from human epidermis together with 1H-NMR spectra and mass spectra demonstrating their molecular weights. The structure of molecular species containing trihydroxysphingosine having a double bond is novel.

Adolescent↗
PubMed1989

N-terminal half of a mitochondrial presequence peptide takes a helical conformation when bound to dodecylphosphocholine micelles: a proton nuclear magnetic resonance study.

Two-dimensional proton nuclear magnetic resonance (NMR) spectra of a synthetic peptide (p25) corresponding to the amino-terminus of the yeast mitochondrial cytochrome oxidase subunit IV precursor protein have been analyzed. Sequence-specific resonance assignments of the peptide have been made in the presence of micelles of a phospholipid analog, perdeuterated dodecylphosphocholine (DPC), with the aid of such techniques as HOHAHA, DQF-COSY, and NOESY. The interresidue nuclear Overhauser effects (NOEs) indicate that the N-terminal half of p25 (S3-F11) takes a helical structure while the C-terminal half does not take a regular secondary structure. Addition of DPC to the solution of p25 induced chemical shift changes only of the resonances from the residues in the N-terminal half, suggesting that the N-terminal half of p25 is directly involved in binding to DPC. The induced helical structure in the N-terminal half at a lipid-water interface may be important in the ability of this presequence to direct a "passenger" protein into mitochondria.

Choline↗
PubMed1989

Binding modes of inhibitors to ribonuclease T1 as elucidated by the analysis of two-dimensional NMR.

Aromatic proton and high field shifted methyl proton resonances of RNase T1 complexed with Guo, 2'GMP, 3'GMP or 5'GMP were assigned to specific amino acid residues by 2D-NMR spectra in comparison with the crystal structure of RNase T1-2'GMP complex. The spatial proximities of amino acid residues as elucidated by NOESY spectra were found to be quite similar among free RNase T1 and the inhibitor complexes, showing that large conformational changes did not occur upon complex formation. However, small but appreciable conformational changes were induced which were reflected by the systematic chemical shift changes of some amino acid residues in the active site. Furthermore, we confirmed that RNase T1 contains two specific binding sites, one for the guanine base and the other for the phosphate moiety. The inhibitors are forced to adapt their conformations to fit the guanine base and the phosphate moiety to each binding site on the enzyme. This is consistent with our previous studies that 2'GMP and 3'GMP take syn form as a bound conformation, while 5'GMP takes anti conformation around glycosidic bonds.

Endoribonucleases↗
PubMed1988

1H-NMR investigation of the interaction between RNase T1 and a novel substrate analog, 2'-deoxy-2'-fluoroguanylyl-(3'-5')uridine.

The interaction between RNase T1 and a non-hydrolysable substrate analog, 2'-deoxy-2'-fluoroguanylyl-(3'-5')uridine (GfpU), was investigated using 1H-NMR spectroscopy. In the complex, the Gfp portion takes the syn form around the glycosidic bond and the 3'-endo form for the ribose moiety, similar to those found in 3'-GMP and 2'-deoxy-2'-fluoroguanosine 3'-monophosphate (Gfp). However, in contrast to the cases of these two inhibitors, the complex formation with GfpU at pH 6.0 was found to shift the His-40 C2 proton resonance of RNase T1 to high field as much as 1 ppm. At pH 6.0, this histidine residue appears to be unprotonated in the complex, but is protonated in the free enzyme (pKa of His-40 being 7.9). His-40, rather than Glu-58, is probably involved in the catalytic mechanism as a Lewis base, supporting the recent results from site-directed mutagenesis.

Aspergillus↗
PubMed1988

A novel ganglioside in dogfish brain. Occurrence of a trisialoganglioside with a sialic acid linked to N-acetylgalactosamine.

A novel trisialoganglioside has been isolated from dogfish (Squalus acanthias) brain. From the results of gas chromatography-mass spectrometric analysis of methylated sugars, enzymatic hydrolysis, fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance analysis, its structure was concluded to be (formula; see text) This is the first report of the occurrence of a ganglioside with 3 sialic acid residues separately linked to its gangliotetraosyl backbone.

Acetylgalactosamine↗
PubMed1988

Complete sequence-specific 1H nuclear magnetic resonance assignments for mouse epidermal growth factor.

The 1H NMR spectrum of the mouse epidermal growth factor (53 residues) was analyzed with the use of two-dimensional NMR techniques. All the observable 296 proton resonances were completely assigned in a sequential manner. For the spin system identification, two-dimensional homonuclear Hartmann-Hahn spectrum was useful, especially for arginine and proline residues. The easy spin system identification of these long-side-chain-bearing amino acid residues greatly facilitated the sequence-specific resonance assignment of the epidermal growth factor.

Amino Acids↗
PubMed1988

A single autosomal gene controlling the expression of the extended globoglycolipid carrying SSEA-1 determinant is responsible for the expression of two extended globogangliosides.

Two extended globogangliosides, designated as Z1 and Z2, were purified from the kidney of DBA/2 mice. By means of GLC, 1H-NMR spectroscopy, negative-ion fast atom bombardment mass spectrometry, methylation analysis, and enzymatic digestion, the structures of Z1 and Z2 were determined to be NeuGc alpha 2-3Gal beta 1-3GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-Cer and NeuGc alpha 2-8NeuGc alpha 2-3Gal beta 1-3GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-Cer, respectively. Since Z1 and Z2 were not detectable in the kidney of C57BL/10 and 6, BALB/c, and WHT/Ht mice, the mode of genetic control on Z1 and Z2 expression was examined by mating experiments between C57BL/10 or BALB/c and DBA/2. The results indicated that the expression of Z1 and Z2 is a recessive phenotype and that DBA/2 mice carry a single autosomal recessive gene. In the previous paper, we reported that DBA/2 mice do not express GL-Y (Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6(Gal beta 1-3)Gb4Cer) but express GL-X (Gal beta 1-3Gb4Cer) in the kidney (J. Biochem. 101, 553-562 (1987)), and that a single autosomal defective gene responsible for the defective GL-Y expression was identified by genetic analysis (J. Biochem. 101, 563-568 (1987)).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Tertiary structure of mouse epidermal growth factor determined by two-dimensional 1H NMR.

The tertiary structure of mouse epidermal growth factor (EGF) in solution (28 degrees C, pH 2.0) was studied by two-dimensional NMR spectroscopy. Proton-proton distance constraints derived from NOESY spectra were used to construct a mechanical molecular model of mouse EGF, which was subsequently checked by means of a preliminary distance geometry calculation. The chain-folds in the two structural domains of mouse EGF were very similar to those previously reported (Montelione et al. (1987) Proc. Natl. Acad. Sci. U.S. 84, 5226-5230). However, the relative orientations of the two domains were different. Because we could assign much more inter-domain NOEs, the relative orientations of the two domains were well determined in our model. The hollow between the two domains may function as a binding site for the EGF receptor.

Animals↗