Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human tooth slabs were used to observe the effect of several kinds of organic acids and proteolytic enzymes on the production of artificial caries of enamel. Acidic gels were made by formic, acetic and lactic acids separately or in mixed form. The experiments were done in a period of 10 days. After this the specimens were prepared in ground sections and observed under optic microscope. The depth of the artificial lesions was measured by a micrometric scale in the eye lens of the microscope. The enzymes used for investigation were papain, trypsin and collagenase. The surfaces of the tooth were treated with fresh enzyme solutions every day and then with mixed acid gels. This was done alternately every day in a period of ten days. The results showed that lesions produced by formic acid gel were deeper than those produced by other acids or mixed acid gels. No effect was observed on the depth of the lesion by enzymatic treatments.
Hua Xi Yi Ke Da Xue Xue Bao 1990 Sep
PMID:[The effect of several acids and proteolytic enzymes on the production of artificial caries]. 209 67

Papain, trypsin and collagenase were used in the experiment for the study of their effects on the demineralization of enamel surface by organic acids in vivo. No effect of any of the enzymes was observed. The use of papain and trypsin in treating tooth surfaces in vitro, no matter whether sodium bisulfite was used, showed no effect on the demineralization of the enamel by mixed organic acids. But, by the analysis of amino acids in the enzyme solutions before and after treating tooth surface, it was shown that some proteinous substances were destroyed. Accordingly, it can be suggested that the enzyme takes no part in the destruction of the inorganic tooth substance.
Hua Xi Yi Ke Da Xue Xue Bao 1990 Jun
PMID:[Effects of proteolytic enzymes on demineralization of enamel]. 216 74

In order to increase the sensitivity to immunostaining in formalinfixed, paraffin-embedded tissues, we developed an immunohistochemical method by microwave heating of tissue sections instead of trypsin digestion. The results of this study showed that there was no positive P53 protein reaction in normal and hyperplastic mucousa of human mouth, whereas 90% (27/30) of cases with dysplasia, 61% (30/49) of oral squamous cell carcinomas and 86% (13/15) of regional metastatic lymph nodes were positive. And all positive reactions were localized in nuclei. Comparison of these positive results of p53 gene mutation detected by silver staining method with the results by polymerase chain reaction-single strand conformation polymorphism analysis did not reveal matched results, especially during the precancerous period. The authors analysed the causes of difference not only by methodology, but also by cell groups which had different genetic changes in tissues of precancerous lesions.
Hua Xi Yi Ke Da Xue Xue Bao 1996 Sep
PMID:[The role of p53 gene during the development of human oral malignant lesions: a comparative study of p53 gene mutation with P53 protein positive immunostaining]. 938 53

In this paper, a study on preparation of human insulin by immobilized enzyme-assisted semisynthesis is reported for the first time in our country. Porcine insulin with Thr(Bu(t)OB(t) catalyzed by immobilized trypsin has been converted into human insulin via a two-step transpeptidation. With the systematic technique of optimization, the rate of transpeptidation is 66%-70%. PAGE photometry is used to determine the conversion rate of semisynthesis. PAGE and C-terminal analysis of protein are adopted to identify the semisynthesis human insulin.
Hua Xi Yi Ke Da Xue Xue Bao 1998 Sep
PMID:[A study of immobilized enzyme-assisted semisynthesis of human insulin]. 1068 91

The purpose of this study was to investigate the types and activities of proteolytic enzymes in human root surface plaque. Sephadex G-200 gel filtration, fluorometry and spectrometry were used to isolate, purify and demonstrate the activities of proteolytic enzymes. The results indicated that three enzymes were present in the root surface plaque, namely leucine amino peptidase, dipeptidyl peptidase i.v. and trypsin-like proteinase, and their activities were different.
Hua Xi Yi Ke Da Xue Xue Bao 1998 Dec
PMID:[Isolation, purification and activity measurement of proteolytic enzymes in dental plaque]. 1074 47

This study was intended to explore the relationship between the proteolytic enzymes in dental plaque and the patient's age and sex. Fluorometry and spectrometry were used to separately determine the activities of leucine amino peptidase, dipeptidyl peptidase IV and trypsin-like proteinase in children(10 boys and 10 girls), adults(n = 20) and elderly people(n = 10). The results showed that sex almost had no influence on the activities of the three enzymes in dental plaque in the children(P > 0.05), and with the increase of age, the activities of the three enzymes apparently increased (P < 0.01). These findings imply that the proteolytic enzymes may only play important roles in root lesions.
Hua Xi Yi Ke Da Xue Xue Bao 1999 Dec
PMID:[The activities of proteolytic enzymes in dental plaque of patients in different age-sex groups]. 1138 41

To investigate the behavoir of TMJ condylar cartilage cells in vitro, the mandibular condylar cartilage cells were harvested from a 5-month-old human fetus by dissection and sequential digestion with 0.25% trypsin and 0.2% collagenase (type II). The isolated cells were cultured in DMEM medium and identified by histochemical and immunohistochemical methods. Cell proliferation, morphology and ultrastructure were observed by phase-contrast microscope, cytologic staining and electronic microscope. In primarily cultured cells, polygonal chondroblast-like cells dominated and they were confirmed by the positive result of immunohistochemical examination for type II collagen and Toludin blue staining. In conclusion, the TMJ cells in this culture system kept their phenotype in vivo.
Hua Xi Kou Qiang Yi Xue Za Zhi 1997 Aug
PMID:[The culture of TMJ condylar cartilage cells and study on their biological behaviors in vitro]. 1147 91

The expression difference of trypsin gene between deltamethrin-resistant strain and -susceptible strain of Culex pipiens pallens was further investigated, and the results showed that the expression of trypsin gene were respectively 4.3 and 3.9 fold more in the resistant strain than in the susceptible strain, by reverse Northern blot and Northern blot assays. A full-length trypsin cDNA of 909 base pairs (GenBank/NCBI AY034060) with an open reading frame of 786 base pairs was cloned from the constructed cDNA library by the rapid amplification of cDNA ends, and the deduced protein of 261 amino acids was 55% homologous with Anopheles gambiae trypsin.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002 Jan
PMID:[Cloning and sequence analysis of full-length trypsin cDNA of Culex pipiens pallens]. 1195 30

To explore the differential proteomic expressions between human lung adenocarcinoma cell line A-549 and normal cell line HBE, a series of methods, including immobilized pH gradient-two dimensional polyacrylamide gel electrophoresis, silver staining, PDQuest 2-DE software analysis, peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching, were used to separate and identify the differential proteomic expressions between A-549 and HBE. The results showed that the good 2-DE pattern including high resolution and reproducibility was obtained. After silver staining, the 2-DE image analysis by PDQuest 2-DE software detected average (890 +/- 38) spots in A-549, and (757 +/- 27) spots in HBE. The average positional deviation of the matched spots between A-549 and HBE 2-DE maps was (2.85 +/- 0.48) mm in IEF direction, and (2.69 +/- 0.37) mm in SDS-PAGE direction. The differential proteomic expression analysis found that there were 535 matched spots between A-549 and HBE 2-DE maps, 355 spots that were not matched in A-549, 222 spots that were not matched in HBE. 18 differential spots (8 spots in A-549 and 10 spots in HBE) were cut off from silver staining gel at random, digested in gel with TPCK-trypsin, measured with MALDI-TOF-MS and searched in the SWISS-PROT database with PeptIdent software. 18 protein were preliminarily identified. These proteins were related to cell signal transduction, cell metabolism, proliferation and differentiation etc. There was a significant difference at protein level between human lung adenocarcinoma cell line A-549 and normal cell line HBE. It suggests that the differential expression analysis of proteomes may be useful to further study of the related proteins and the molecular markers of lung adenocarcinoma.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002 Jan
PMID:[Differential proteomic analysis of human lung adenocarcinoma cell line A-549 and of normal cell line HBE]. 1195 34

N- and C-half molecules containing a single iron-binding site were simultaneously obtained from trypsin digest of iron-saturated pig transferrin. The activities of the pig serum transferrin and of its N- and C-half molecules to bind the human placental membrane transferrin receptor were compared. The results indicate that the receptor-binding site of pig transferrin may be located at the C-half molecule of the transferrin.
Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002 Mar
PMID:[Preparation, characterization and receptor-binding capacity of pig serum transferrin half-molecules containing a single iron-binding site]. 1200 99


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