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Biomedical subjects

H I Jung

Publications and source records attributed to H I Jung.

5 recordsLinked to original sources
PubMed2000

Sites of limited proteolysis in the pyruvate decarboxylase component of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus and their role in catalysis.

The E1 component (pyruvate decarboxylase) of the pyruvate dehydrogenase complex of Bacillus stearothermophilus is a heterotetramer (alpha2beta2) of E1alpha and E1beta polypeptide chains. The domain structure of the E1alpha and E1beta chains, and the protein-protein interactions involved in assembly, have been studied by means of limited proteolysis. It appears that there may be two conformers of E1alpha in the E1 heterotetramer, one being more susceptible to proteolysis than the other. A highly conserved region in E1alpha, part of a surface loop at the entrance to the active site, is the most susceptible to cleavage in E1 (alpha2beta2). As a result, the oxidative decarboxylation of pyruvate catalysed by E1 in the presence of dichlorophenol indophenol as an artificial electron acceptor is markedly enhanced, but the reductive acetylation of a free lipoyl domain is unchanged. The parameters of the interaction between cleaved E1 and the peripheral subunit-binding domain of the dihydrolipoyl acetyltransferase E2 component are identical to those of the wild-type E1. However, a pyruvate dehydrogenase complex assembled in vitro with cleaved E1p exhibits a markedly lower overall catalytic activity than that assembled with untreated E1. This implies that active site coupling between the E1 and E2 components has been impaired. This has important implications for the way in which a tethered lipoyl domain can interact with E1 in the assembled complex.

Amino Acid Sequence↗
PubMed1997

Colchicine activates actin polymerization by microtubule depolymerization.

Swiss 3T3 fibroblasts were treated with the microtubule-disrupting agent colchicine to study any interaction between microtubule dynamics and actin polymerization. Colchicine increased the amount of filamentous actin (F-actin), in a dose- and time-dependent manner with a significant increase at 1 h by about 130% over control level. Confocal microscopic observation showed that colchicine increased F-actin contents by stress fiber formation without inducing membrane ruffling. Colchicine did not activate phospholipase C and phospholipase D, whereas lysophosphatidic acid did, indicating that colchicine may have a different mechanism of actin polymerization regulation from LPA. A variety of microtubule-disrupting agents stimulated actin polymerization in Swiss 3T3 and Rat-2 fibroblasts as did colchicine, but the microtubule-stabilizing agent taxol inhibited actin polymerization induced by the above microtubule-disrupting agents. In addition, colchicine-induced actin polymerization was blocked by two protein phosphatase inhibitors, okadaic acid and calyculin A. These results suggest that microtubule depolymerization activates stress fiber formation by serine/threonine dephosphorylation in fibroblasts.

3T3 Cells↗
PubMed1995

Isolation and characterization of guamerin, a new human leukocyte elastase inhibitor from Hirudo nipponia.

A new human leukocyte elastase inhibitor was extracted and purified from a Korean native leech Hirudo nipponia. The inhibitor, called guamerin, has a molecular weight of 6,110 and shows inhibition constant (Ki) of 8.1 x 10(-14) M. It is stable at a wide range of pH from 1 to 11 and heat-stable up to 90 degrees C. The complete amino acid sequence of guamerin reveals a cysteine-rich polypeptide of 57 amino acid residues that shows no similarity to any known elastase inhibitors but has 51% sequence homology with hirustasin. Guamerin has identical spacing of 10 cysteine residues as antistasin-type serine proteinase inhibitors, but the P1 reactive site residue is Met36 instead of Arg. The neighboring sequence of the reactive site consists primarily of hydrophobic amino acid residues. Based on examinations of the target proteinases and the reactive site specificity, guamerin is a new low molecular weight protein that inhibits elastases.

Amino Acid Sequence↗
PubMedDate not supplied

[A study of psychiatric patients perceived effect and expectancy of activity therapy].

The intent of this descriptive study is to investigate the patients perceived effect and expectance of activity therapy. The subjects for this study were 56 patients from the psychiatric ward in Severance Hospital. The data were collected during the period from June 1, 1991 to January 18, 1992. The effect and expectance of the activity therapy was measured using a questionnaire developed by this study's investigators. The date were analyzed by descriptive statistics, t-test and one-way ANOVA, using the SPSS program. The results of this study can be summarized as following; 1. For motivation for the activity therapy, the response range was from 64.3% to 89.3%, that is, it showed a relatively positive response. 2. For the degree of improvement according to the nurse's method in the activity therapy, it was shown that the nurses need professional skill and meeting after activity therapy. 3. For the relevance of the nurse in the activity therapy, 90% of the subjects had a positive answer for all of the activity therapy except the painting therapy. 4. For the perceived effect of the activity therapy, the following results were obtained. 1) 92% of the subjects had a positive response to the dance therapy, that is-I am vigorous physically. 2) 90% of the subjects had a positive response to the reading therapy, that is-I acquire good ideas and instruction. 3) 98.1% of the subjects had a positive response to the recreation therapy, that is-I am joyful. 4) 88.9% of the subjects had a positive response to the writing therapy, that is-I am interested and become acquainted with other patients. 5) 86.8% of the subjects had a positive response to the occupation therapy, that is-I am happy when I work. 6) 92.6% of the subjects had a positive response to the painting therapy, that is-I can express myself in painting. 7) 87.3% of the subjects had a positive response to the music therapy, that is-I am comforted. 5. For the expectance related to the activity therapy, 97.1% of the subjects had the most positive response to the music therapy which is a pleasant comfortable time. From the above-mentioned findings, it is suggested that psychiatric nurses need to development systematic and professional group activity therapy, and know the patient premorbid hobbies, interests and occupations.

Analysis of Variance↗