Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In ongoing studies, we have tested resected lung cancers from 41 men and 49 women; of those with primary lung cancer, 46 patients are free of disease and 35 have died of cancer or have persistent disease. Measurements and studies were as follows: total cellular deoxyribonucleic acid content by image analysis (n = 77); total genomic deoxyribonucleic acid methylation state and banding patterns from probed Southern blots (n = 36); radioimmunoassay for motilin, bombesin, gastrin, vasoactive intestinal peptide, and cholecystokinin (n = 18); and cytogenetic analysis (n = 39). All lung cancers were hyperploid. Adenocarcinomas and epidermoid carcinomas were generally hexaploid to nearly septaploid; comparisons by stage and histologic features suggested potential prognostic correlations. There was general hypomethylation of deoxyribonucleic acid (p less than 0.001). Deoxyribonucleic acid digests from restriction endonuclease Hpa II, when probed with deoxyribonucleic acid homologous to KPN, showed banding patterns that separated histologically indistinguishable primary adenocarcinomas and metastatic adenocarcinomas from one another. Cancers studied with radioimmunoassay were all negative for polypeptide hormones. Five cancers grew adequately in vitro to permit study of 190 detailed karyotypes (20 to 50 per tumor). Chromosome modal numbers ranged from 49 to 109. There were from 4 to 20 clearly abnormal marker chromosomes per tumor; abnormality derived from chromosome 1 was prevalent. Ten of 19 tumors xenotransplanted to nude mice were carried through two to five transplant generations without a change in histologic patterns.
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PMID:Biochemical and cytogenetic studies of human lung cancers. 319 97

We have determined the entire structure of human cholecystokinin (CCK) gene, which is 7 kb in size and separated into three exons. S1 endonuclease analysis has shown two putative transcription initiation sites that are preceded by 'TATA' equivalent sequences located 39 bp and 35 bp upstream from these sites. The promoter region contains five 'G-C box'-like sequences, which are believed to be sp 1-binding sites. By chromosome sorting in combination with velocity sedimentation and Southern hybridization, the human cck gene was mapped on the short arm of human chromosome 3.
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PMID:Structure of human cholecystokinin gene and its chromosomal location. 358 83

The two known receptors mediating the actions of cholecystokinin (CCK) and gastrin, CCK type A (CCKAR) and CCK type B (CCKBR) receptors, are G protein-coupled receptors having approximately 50% amino acid homology. Both the CCKAR and CCKBR have high affinity for sulfated CCK peptides, while only the CCKBR has high affinity for gastrin peptides. To determine the structural basis for the selectivity of the CCKBR for gastrin, we first constructed a series of CCKB/AR chimeras in which restriction endonuclease-defined segments of the CCKBR were replaced with the corresponding segments of the CCKAR. Chimeras transiently expressed in COS-1 cells were screened for the selective loss of gastrin affinity according to the displacement of 125I-labeled Bolton-Hunter-CCK-8 binding by gastrin-17-I and CCK-8. The sequence spanning from transmembrane domain III (TM III) to TM V was the only segment that resulted in the selective loss of gastrin affinity. This segment could account for 100 of the expected 300-fold lower affinity of gastrin-17-I observed for the control CCKAR compared to the control CCKBR. Using site-directed mutagenesis in this segment of the CCKBR, we identified a sequence of 5 amino acids in the second extracellular loop responsible for this 100-fold selective loss in gastrin affinity. 125I-labeled Bolton-Hunter-CCK-8 binding displacement by L365,260 (a CCKBR selective antagonist) was unaffected by the changes in these 5 amino acids. These results present for the first time the identification of the amino acid sequence of the CCKBR conferring the majority of the selectivity for gastrin.
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PMID:A segment of five amino acids in the second extracellular loop of the cholecystokinin-B receptor is essential for selectivity of the peptide agonist gastrin. 866 21

The aims of this research were to construct prokaryotic expression vector containing fusion gene of Cholecystokinin 39 (CCK39) of pig and Urease subunit B (UreB) of coliform bacteria, and then to express the fusion protein in recombinant Escherichia coli BL21(DE3). The CCK39 gene was amplified by RT-PCR from the extracted total RNA of pig's duodenum, and the UreB gene was then amplified by PCR from the extracted plasmid DNA of bacillus of coliform bacteria from pig's intestinal content. Then the CCK39 and the UreB were inserted into the prokaryotic expression vector pET43a(+) to construct a recombinant fusion expression vector pET43a(+)/CCK39/UreB and then, the recombinant vector was identified by PCR, endonuclease digestion and sequence analysis. It was identified that the gene fragment of CCK39 at length of 117 bp and UreB at length of 324 bp were amplified and cloned into the vector pET43a(+) successfully. The recombinant vector was transformed into Escherichia coli BL21(DE3) and induced the expression of CCK39/UreB fusion protein with a molecular mass of approximately 80 kD by using isopropylthio-beta-D-galactoside (IPTG) as inducer. The fusion protein was mostly located in the cytoplasm and it was soluble. The soluble protein was collected and purified by Ni2+-NTA column chromatograph and then reached a purity of more than 95%. It was proved by western blotting that the fusion protein could react with rabbit anti-CCK8 antiserum and rabbit anti-UreB antiserum. Therefore, the expressed fusion protein has good antigenicity. This work established a good foundation for further study on the production of anti-CCK/Urease vaccines.
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PMID:[Construction and expression of the fusion gene CCK39/UreB in recombinant Escherichia coli BL-21(DE3)]. 1944 Dec 24