Biomedical subjects

E Hashimoto

Publications and source records attributed to E Hashimoto.

At least 163 records · Page 9Linked to original sources

PubMed1977

Intrinsic activity of guanosine 3',5'-monophosphate-dependent protein kinase similar to adenosine 3',5'-monophosphate-dependent protein kinase. I. Phosphorylation of histone fractions.

Guanosine 3',5'-monophosphate (cyclic GMP)-dependent protein kinase partially purified from silkworm pupae reacts preferentially with H1, H2A, and H2B histones but not with H3 AND H4 histones. However, the latter can serve as substrates in the presence of a stimulatory modulator as described by Kuo and Kuo (J. Biol. Chem. 251, 4283-4286 (1976)). With H2B histone as substrate high Mg2+ concentrations (50-100 mM) are necessary for the maximum rate of reaction. Although effects of the modulator and Mg2+ vary significantly with the histone fractions employed, analysis on the phosphorylation of histone fractions provides evidence that cyclic GMP-dependent protein kinase possesses an intrinsic activity that is similar to that of adenosine 3',5'-monophosphate-dependent protein kinase.

Animals↗

PubMed1977

Intrinsic activity of guanosine 3',5'-monophosphate-dependent protein kinase similar to adenosine 3',5'-monophosphate-dependent protein kinase. II. Phosphorylation of ribosomal proteins.

Guanosine 3',5'-monophosphate (cyclic GMP)-dependent protein kinase purified from silkworm pupae reacts with rat liver ribosomal proteins when a stimulatory modulator (Kuo, W.N. & Kuo, J.F. 1976) J. Biol. Chem. 251, 4283-4286) is added to the reaction mixture. Judging from autoradiogram of the radioactive proteins separated by electrophoresis on sodium dodecyl sulfate-polyacrylamide slab gel, the protein kinase utilizes the same proteins as those phosphorylated by adenosine 3',5'-monophosphate (cyclic AMP)-dependent protein kinase. Fingerprint maps of the tryptic phosphopeptides of radioactive ribosomal proteins, which are phosphorylated by these two classes of protein kinases, are very similar. These results suggest that cyclic GMP-dependent protein kinase possesses an intrinsic activity that is similar to that of cyclic AMP-dependent protein kinase.

Animals↗

PubMed1977

Stimulatory effect of histones on phosphorylation of nuclear phosphoproteins.

Effect of histones on phosphorylation of nuclear phosphoproteins was studied using two species of phosphoprotein kinases with different kinetic and catalytic properties; namely, protein kinases A1 and A2 (Takeda, M., Matsumura, S., & Nakaya, Y. (1974) J. Biochem. 75, 743-751). The reaction rate for protein kinase A1 was markedly enhanced when histone or polylysine was added to the reaction mixture. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the basic protein served as a stimulator rather than acted as a substrate in this reaction. In contrast, when protein kinase A2 was employed, the stimulatory action of these basic proteins was less marked than for protein kinase A1. It seems likely that the phosphorylation of nuclear phosphoproteins, particularly the reaction catalyzed by protein kinase A1, may be strongly influenced by histones which are integrated in the chromatin structure.

Animals↗

PubMed1977

Studies on the normal polarcardiograms using the inferosuperior axis as the polar axis.

Polarcardiography made possible not only to let us know the polar coordinates of the cardiac vectors at any instant very easily, but also to express the time-related curve of the polar coordinates of the cardiac vectors, which vary as function of time, in easily understandable analogue pattern. Especially it was difficult to grasp the time-related curves of the polar coordinates of ST segment and T wave by means of the conventional electrocardiography and vector-cardiography. QRS waves, ST segments and T waves of the spatial magnitude ECG and I-S latitude ECG in normal subjects were classified into the several definite patterns.

Adult↗

PubMed1977

[Studies on the normal polarcardiogram using the posteroanterior axis as the polar axis (author's transl)].

Polarcardiograms using the posteroanterior axis as the polar axis were recorded in 112 cases of the clinically healthy subjects. QRS wave with small notch or slur both in front and behind of the main triangular configuration with narrow base were most frequently observed in the frontal magnitude ECG. T wave showed simple monophasic upright wave with the mildly sloping ascending limb and the relatively rapidly sloping descending limb. The magnitude of the maximum QRS vector and the maximum QRS vector time in frontal plane were very similar with those of the spatial QRS vector. The quantitative values obtained by the measurement of the polarcardiograms agreed well with those obtained by the vectorcardiograms reported by the various authors. Polarcardiography made possible not only to know the polar coordinates of the cardiac vector at any instant very easily, but also to express the time-related curve of the polar coordinates, which vary as a function of time, in easily understandable analogue pattern. QRS and T waves of the magnitude, the alpha-longitude and P-A latitude ECG in the normal subjects were classified into the several definite patterns.

Adult↗

PubMed1977

[Studies on the reliability of the polarcardiographic records (author's transl)].

Reliability of the polarcardiogram obtained by the newly constructed polarcardiograph, in which the vector sum circuit applying absolute value operations were used for the computation of the magnitude curve, were examined in fifty normal subjects. There was no statistically significant difference between the means of the measured values of the polarcardiogram and of the corresponding polar components calculated from the three scalar ECG concerning all twenty items, namely spatial magnitude, magnitudes in each plane, each longitude and latitude at the time of the spatial maximum QRS and T vectors, except alpha-longitude. Highly significant positive correlations were observed between these two sets of values in all twenty items. Configurations of the pattern obtained by plotting the instantaneous polar components, which were calculated from the three scalar ECG, on the linear time scale were very similar with those of the polarcardiographic records. These findings showed that the records obtained by the newly constructed polarcardiograph were reliable.

Adolescent↗

PubMed1976

Studies on the sites in histones phosphorylated by adenosine 3':5'-monophosphate-dependent and guanosine 3':5'-monophosphate-dependent protein kinases.

Adenosine 3':5'-monophosphate-dependent protein kinase (protein kinase A) purified from silkworm pupae phosphorylated five major fractions of calf thymus histone, whereas guanosine 3':5'-monophosphate-dependent protein kinase (protein kinase G) purified from the same organism reacted preferentially with H1, H2A, and H2B histones. Amino acid analysis of the phosphopeptides which were obtained by proteolytic digestion revealed that both protein kinases A and G showed the abilities to phosphorylate the same serine hydroxyl groups in H1 and H2B histones. Both protein kinases reacted with Ser-38 in H1 histone. With H2B histone as substrate protein kinase A phosphorylated Ser-32 as well as Ser-36, whereas protein kinase G reacted preferentially with Ser-32 and the reaction with Ser-36 was very slow. H3 and H4 histones were practically inactive substrates for protein kinase G. Although H2A histone has not been analyzed, the evidence has raised a possibility that protein kinase G utilizes a portion of the substrate proteins for protein kinase A.

Amino Acids↗

PubMed1976