Codon

Vai trò của gene p53 trong ung thư dạ dày vẫn đang còn tranh cãi. Nghiên cứu này nhằm mục tiêu xác định tỷ lệ các đa hình codon 72 trên gene p53 ở bệnh nhân ung thư dạ dày và đánh giá mối liên quan của các đa hình codon 72 trên gene p53 với một số đặc điểm thương tổn trên nội soi và phân loại mô bệnh học của ung thư dạ dày.

7p viuchiha 06-01-2025 1 0   Download

Bài viết trình bày sự tương tác của yếu tố môi trường và vật chủ chưa được nghiên cứu nhiều trong bệnh sinh UTDD ở nước ta. Đề tài này nhằm mục tiêu: Khảo sát mối liên quan phối hợp của đa hình codon 72 gene TP53 và nhiễm Helicobacter pylori với ung thư dạ dày.

6p viharuno 06-01-2025 2 0   Download

Quá trình hình thành chuỗi polipeptit hay dịch mã là sự kết hợp của luồng thông tin và luồng nguyên liệu tại ribôxôm. Dịch mã là quá trình chuyển trình tự nuclêôtit trong mARN thành trình tự các axit amin trong chuỗi polipeptit. Dịch mã là quá trình phức tạp với sự tham gia của 3 loại ARN: - mARN mang thông tin di truyền mã hóa dưới dạng codon, mỗi codon là một tổ hợp ba nuclêôtit mã hóa cho một axit amin. - rARN là thành phần của ribôxôm, nơi tổng hợp chuỗi pôlipeptit. - tARN là nhân...

4p butmauvang 29-08-2013 478 17   Download

Giải mã sự sống – quá trình phát hiện các mã di truyền Các nhà sinh học phân tử đã giải mã sự sống thành công vào những năm đầu của thập kỷ 1960, khi một loạt các thí nghiệm hợp lý đã giúp làm sáng tỏ sự dịch mã các axit amin từ mỗi codon trên mARN. Codon đầu tiên được giải mã bởi Marshall Nirenberg và cộng sự tại Viện Y học Quốc gia Hoa Kỳ (NIH) vào năm 1961.

5p butmauvang 29-08-2013 83 4   Download

Bài giảng Sinh tổng hợp protein do ThS. Nguyễn Thanh Tố Nhi biên soạn gồm các nội dung chính như: Khái quát, các yếu tố cần thiết, Aminoacyl hóa tARN, tARN và CODON khởi đầu, tiến trình dịch mã,...

52p convitdola 11-12-2017 107 20   Download

Institute for Organic Chemistry, University of Karlsruhe, Germany; 2Institute for Organic Chemistry, Budapest University of Technology and Economics, Hungary Elucidation of the 3D structure of histidine ammonia-lyase (HAL, EC 4.3.1.3) from Pseudomonas putida by X-ray crystallography revealed that the electrophilic prosthetic group at the active site is 3,5-dihydro-5-methylidene-4H-i´ midazol-4-one (MIO) [Schwede, T.F., Retey, J., Schulz, G.E. (1999) Biochemistry, 38, 5355 –5361].

9p system191 01-06-2013 50 3   Download

A clone encoding farnesyl diphosphate synthase (FPPS) was obtained by PCR from a cDNA library made from young leaves of Artemisia annua. A cDNA clone encoding the tobacco epi-aristolochene synthase (eAS) was kindly supplied by J. Chappell (University of Kentucky, Lexington, KY, USA). Two fusions were constructed, i.e. FPPS/ eAS and eAS/FPPS. The stop codon of the N-terminal enzyme was removed and replaced by a short peptide (Gly-SerGly) to introduce a linker between the two ORFs.

8p research12 01-06-2013 37 3   Download

A gene having high sequence homology (45–49%) with the glycerol-1-phosphate dehydrogenase gene from Methanobacterium thermoautotrophicum was cloned from the aerobic hyperthermophilic archaeon Aeropyrum pernix K1 (JCM 9820). This gene expressed in Escherichia coli with the pET vector system consists of 1113 nucleotides with an ATG initiation codon and a TAG termination codon. The molecular mass of the purified enzyme was estimated to be 38 kDa by SDS/PAGE and 72.4 kDa by gel column chromatography, indicating presence as a dimer....

8p research12 01-06-2013 27 4   Download

Amyloid deposits with Arg124 mutated TGFBI protein havebeen identified inautosomal dominant blindingcorneal dystrophies.We assessedin vitrothe mechanisms determin-ing TGFBI protein amyloid transformation involving mutations of Arg124.Eight peptides synthesized following the TGFBI protein sequence, centered on codon Arg124 holding the previously reported amyloidogenic mutations and the respective controls were studied.Cys124 andHis124 mutated peptide preparations contained significantly higher amounts of amyloid than the native peptide....

8p tumor12 22-04-2013 41 2   Download

InEscherichia colithe codons CGG, AGG, UGG or GGG (NGG codons) but not GGN or GNG (where N is non-G) are associated with low expres-sion of a reporter gene, if located at positions +2 to +5. Induction of a lacZ reporter gene with any one of the NGG codons at position +2 to +5 does not influence growth of a normal strain, but growth of a strain with a defective peptidyl-tRNA hydrolase (Pth) enzyme is inhibited.

11p fptmusic 12-04-2013 43 2   Download

The low affinity of peptide nucleic acid (PNA) to hybridize with DNA in the presence of a mismatch endows PNA with a high degree of discriminat-ory capacity that has been exploited in therapeutics for the selective inhibi-tion of the expression of point-mutated genes. To obtain a structural basis for this intriguing property, molecular dynamics simulations are carried out on PNAÆDNA duplexes formed at the Ki-ras proto-oncogene, compri-sing the point-mutated (GAT), and the corresponding wild-type (GGT) codon 12. ...

16p fptmusic 11-04-2013 53 2   Download

Eleven of the codons specifying the amino acids of the flexible catalytic loop [KRRPRPNVAEVM(197–208)] of Bacillus subtilis phosphoribosyl diphosphate synthase have been changed individually to specify alanine. The resulting variant enzyme forms, as well as the wildtype enzyme, were produced in anEscherichia colistrain lacking endogenous phosphoribosyl diphosphate synthase activity and purified to near homogeneity. The B. subtilisphosphoribosyl diphosphate synthase mutant variants K197A and R199A were studied in detail....

9p fptmusic 11-04-2013 30 3   Download

Recent cloning of theXenopus laevis(Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5¢-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon.

0p awards 06-04-2013 42 3   Download

Several oncogenic proteins are known to influence cellular glycosylation. In particular, transfection of codon 12 point mutated H-Ras increases CMP-Neu5Ac: Galb1,4GlcNAc a2,6-sialyltransferase I (ST6Gal I) activity in rodent fibroblasts. Given that Ras mediates its effects through at least three secondary effector pathways (Raf, RalGEFs and PI3K) and that transcriptional control ofmouse ST6Gal I is achieved by the selective use of multiple promoters, we attempted to identifywhichof these parameters are involved in linking the Ras signal to ST6Gal I gene transcription in mouse fibroblasts. ...

12p awards 05-04-2013 44 3   Download

Two histone H4 mRNA variants, H4-v.1 and histogranin mRNAs, were detected in the rat genome and measured in various tissues and isolated alveolar macrophages. Medium to high levels of both mRNAs were present in the liver, adrenal glands, thymus, bone marrow and alveolar macrophag-es. H4-v.1 cDNA contained an open reading frame that coded for unmodi-fied whole histone H4, whereas histogranin cDNA lacked the first ATG codon and contained an open reading frame that coded for modified (Thr89) H4-(84–102). ...

14p inspiron33 25-03-2013 54 5   Download

Lys101Glu is a drug resistance mutation in reverse transcriptase clinically observed in HIV-1 from infected patients treated with the non-nucleoside inhibitor (NNRTI) drugs nevirapine and efavirenz. In contrast to many NNRTI resistance mutations, Lys101(p66 subunit) is positioned at the sur-face of the NNRTI pocket where it interacts across the reverse transcrip-tase (RT) subunit interface with Glu138(p51 subunit).

11p inspiron33 25-03-2013 28 5   Download

Chromosomal rearrangements apparently account for the presence of a pri-mate-specific gene (protease serine 3) in chromosome 9. This gene encodes, as the result of alternative splicing, both mesotrypsinogen and trypsino-gen 4. Whereas mesotrypsinogen is known to be a pancreatic protease, neither the chemical nature nor biological function of trypsinogen 4 has been explored previously.

11p galaxyss3 21-03-2013 41 3   Download

Glutathione peroxidases (EC 1.11.1.9 and EC 1.11.1.12) catalyze the reduc-tion of H2O2or organic hydroperoxides to water or corresponding alcohols using reduced glutathione. Some glutathione peroxidase isozymes have a selenium-dependent glutathione peroxidase activity and present a selenocy-steine encoded by the opal TGA codon.

12p galaxyss3 07-03-2013 48 6   Download

Cytochrome P450 (P450) 4X1 is one of the so-called ‘orphan’ P450s with-out an assigned biological function. Codon-optimized P450 4X1 and a number of N-terminal modified sequences were expressed inEscherichia coli. Native P450 4X1 showed a characteristic P450 spectrum but low expression inE. coliDH5acells (

12p galaxyss3 07-03-2013 43 4   Download

Recent studies have suggested the existence of a novel protein of hepati-tis C virus (HCV) encoded by an ORF overlapping the core gene in the +1 frame (core+1 ORF). Two alternative translation mechanisms have been proposed for expression of the core+1 ORF of HCV-1a in cultured cells; a frameshift mechanism within codons 8–11, yielding a protein known as core+1⁄F, and⁄or translation initiation from internal codons in the core+1 ORF, yielding a shorter protein known as core+1⁄S.

18p media19 04-03-2013 34 3   Download