Polypeptide

Bài giảng môn Hóa sinh - Chương 11: Trao đổi Protein trình bày sự phân giải protein và amino acid, chuyển vị amine, sự biến đổi các sản phẩm của quá trình phân giải amino acid, tổng hợp amino acid, tổng hợp protein, tổng hợp chuỗi polypeptide tại ribosome.

17p partimesinhvien 05-05-2020 66 5   Download

Nội dung chính của chương 4 Cytokines của bài giảng Miễn dịch học trình bày đặc tính chung của các cytokines. Cytokin là các polypeptid được sản xuất khi có kích thích của vi sinh vật hay các kháng nguyên khác nhằm trung gian và điều hòa các phản ứng miễn dịch và viêm.

15p model_12 23-04-2014 269 58   Download

Insulin Insulin là một protein được tuyến tụy tiết ra nhằm điều hòa lượng đường trong máu. Cơ thể thiếu hụt insulin trong máu sẽ làm rối loạn hầu hết các quá trình trao đổi chất ở cơ thể, dẫn đến tích tụ nhiều đường trong nước tiểu. Trong cơ thể, insulin được tổng hợp dưới dạng proinsulin gồm ba chuỗi polypeptide: A, B và C. Khi proinsulin chuyển thành insulin, chuỗi C được loại bỏ, hai chuỗi A và B nối với nhau bởi hai cầu disulfide (-S-S-). Để điều trị bệnh này người ta thường tiêm...

7p butmaulam 23-09-2013 427 49   Download

Phân loại protease: Dựa vào vị trí tác động trên mạch polypeptide, exopeptidase được phân chia thành 2 loại: Aminopeptidase: xúc tác thủy phân liên kết peptide ở đầu N tự do của chuỗi polypeptide để giải phóng ra một amino acid, các polypeptide

13p and_12 08-08-2013 103 20   Download

Nguyên nhân Gây bệnh là Picornavirus, thuộc họ Picornaviridae cấu trúc aixt nhân là ARN, virus hình cầu có 20 mặt, đường kính 3032nm. Hệ thống gen (genome) là một mạch RNA, chiều dài 10,2kb, cấu trúc capsid có 3 phần (55, 40 và 24 kD) và một đoạn polypeptide phụ (58kD). Virus ký sinh tế bào biểu mô và dưới biểu mô đuôi. Triệu chứng Dấu hiệu bệnh lý tương tự như bệnh vi khuẩn. Bệnh dạng cấp tính đuôi tôm chuyển màu đỏ và bệnh mạn tính có nhiều đốm nhiễm melani do biều bì hoại tử....

8p nhonnhipnp 13-06-2013 62 3   Download

Many groups of proteins play important roles in the cell’s response to various stresses. The molecular chaperone GroEL of Escherichia coli represents one such highly conserved family of stress proteins. We have observed that isolated GroEL complexes from stationary cultures contain various polypeptides that can be released from the chaperonin by GroES and/or ATP, and identified two such polypeptides as the proteins GatY and UP12.

9p system191 01-06-2013 28 3   Download

The main component of cerebral amyloid angiopathy (CAA) in Alzheimer’s disease is the amyloid-b protein (Ab), a 4-kDa polypeptide derived from the b-amyloid protein precursor (APP). The accumulation of Ab in the basement membrane has been implicated in the degeneration of adjacent vascular smooth muscle cells (VSMC). However, the mechanism of Ab toxicity is still unclear. In this study, we examined the effect of substrate-bound Ab on VSMC in culture. The use of substrate-bound proteins in cell culture mimics presentation of the proteins to cells as if bound to the basement membrane.

9p system191 01-06-2013 43 5   Download

Recently, we have identified and purified minisatellite DNA binding proteins (MNBPs) that bind to the mouse hypervariable minisatellite Pc-1, from NIH3T3 cells. This study describes the isolation and characterization of a mouse leucine-rich protein (mLRP130) as one of the MNBPs that binds to the C-rich strand of Pc-1. The mLRP130 cDNA was demonstrated to encode a polypeptide of 1306 aminoacid residues with a deduced molecular mass of 137 kDa, and the mLRP130 mRNA is detected in various organs, including heart, brain, liver, skeletal muscle, kidneys and testes.

7p system191 01-06-2013 25 4   Download

Transglutaminase (TGase) catalyses the post-translational modification of proteins by transamidation of available glutamine residues. While several TGase genes of fish and arthropods have been cloned and appear to have similar structures to those of mammals, no homologous gene has been found in lower eukaryotes. We have cloned the acellular slime mold Physarum polycephalum TGase cDNA using RT-PCR with degenerated primers, based on the partial amino acid sequence of the purified enzyme. The cDNA contained a 2565-bp ORF encoding a 855-residue polypeptide.

10p research12 01-06-2013 48 4   Download

A technique has been developed to search a proteome database for new members of a functional class of membrane protein. It takes advantage of the highly conserved secondary structure of functionally related membrane proteins. Such proteins typically have the same number of transmembrane domains located at similar relative positions in their polypeptide sequence. This gives rise to a characteristic pattern of peaks in their hydropathy profiles.

7p research12 01-06-2013 32 4   Download

Recently, we identified novel avian and amphibian hypothalamic neuropeptides that inhibited gonadotropin release and stimulated growth hormone release. They were characterized by a similar structure including theC-terminal LPLRF-NH2motif. To clarify that the expression of these novel hypothalamicneuropeptides is aconservedproperty in vertebrates, we characterized a cDNA encoding a similar novel peptide, having LPLRF-NH2 from the goldfish brain, by a combination of 3¢and 5¢rapid amplification of cDNA ends (RACE). ...

9p research12 29-04-2013 38 4   Download

AnN-acyl-D-amino acid amidohydrolase (N-D-AAase) was identified in cell extracts of a strain, Iso1, isolated from an environment containing N-acetyl-D-methionine. The bac-terium was classified as Variovorax paradoxusby phylo-genetic analysis. The gene was cloned and sequenced. The gene consisted of a 1467-bpORF encoding a polypeptide of 488 amino acids. TheV.

11p research12 29-04-2013 44 3   Download

2S albumin storage proteins fromrapeseed (Brassica napus), called napins, consist of two different polypeptide chains linked by disulphide bridges, which are derived by proteo-lytic cleavage froma single precursor. The precursor formof the napin BnIb (proBnIb) has been cloned using a PCR strategy and sequenced.

8p research12 29-04-2013 40 2   Download

Biosynthesis ofmucin-typeO-glycans is initiated by a family of UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferases, which contain several conserved cysteine resi-dues among the isozymes. We found that a cysteine-specific reagent, p-chloromercuriphenylsulfonic acid (PCMPS), irreversibly inhibited one of the isozymes (GalNAc-T1). Presence of either UDP-GalNAc or UDP during PCMPS treatment protected GalNAc-T1 from inactivation, to the same extent.

9p research12 23-04-2013 37 3   Download

A new approach of predicting structural classes of protein domain sequences is presented in this paper. Besides the amino acid composition, the composition of several dipeptides, tripeptides, tetrapeptides, pentapeptides and hexapeptides are taken into account based on the step-wise discriminant analysis. The result of jackknife test shows that this new approach can lead to higher pre-dictive sensitivityand specificityfor reduced sequence similaritydatasets.

7p research12 23-04-2013 33 3   Download

The characterization of the gene encodingLeishmania donovaniphosphofructokinase (PFK) and the biochemical properties of the expressedenzyme are reported.L. donovani has a singlePFKgene copyperhaploidgenome that encodes a polypeptide with a deducedmolecular mass of 53 988 and a pI of 9.26. The predicted amino acid sequence contains a C-terminal tripeptide that conforms to an established signal for glycosome targeting.

12p research12 23-04-2013 62 3   Download

Antibacterial peptides were isolated fromhuman peripheral granulocytes of a healthy donor who had been treated with granulocyte-colony stimulating factor (G-CSF) and cortisol. Peptides were solubilized in acidi®ed chloroform/methanol, and partitioned in chloroform/methanol/water. Water-soluble polypeptides were separated by cation-exchange and reversed-phase chromatography. Several previously char-acterized antibacterial polypeptides were identi®ed; defen-sins 1±3, defensin 4, lysozyme, eosinophil cationic protein, and calgranulin A. ...

7p research12 23-04-2013 26 3   Download

Mammalian tubulins and actins attain their native con-formation following interactions with CCT (the cytosolic chaperonin containing t-complex polypeptide 1). To study the b-tubulin folding in lower eukaryotes, an isotype of b-tubulin (b-T1) from the Antarctic ciliate Euplotes focardii, was expressed in Escherichia coli. Folding analysis was performed by incubation of the 35 S-labeled, denatured b-T1 in the presence, or absence, of purified rabbit CCT and cofactor A, a polypeptide that stabilizes folded monomericb-tubulin. ...

7p tumor12 22-04-2013 51 3   Download

The elongation phase of mRNA translation is the stage at which the polypeptide is assembled and requires a substantial amount of metabolic energy. Translation elongation in mammals requires a set of nonribosomal proteins called eukaryotic elongation actors or eEFs. Several of these proteins are subject to phosphorylation in mammalian cells, including the factors eEF1A and eEF1B that are involved in recruitment of amino acyl-tRNAs to the ribosome.

9p tumor12 22-04-2013 35 2   Download

Cytochrome P450BM3is a self-sufficient fatty acid mono-oxygenase consisting of a diflavin (FAD/FMN) reductase domain and a heme domain fused together in a single polypeptide chain. The multidomain structure makes it an ideal model system for studying the mechanism of electron transfer and for understanding P450 systems in general. Here we report the redox properties of the cyto-chrome P450BM3 wild-type holoenzyme, and its isolated FADreductase andP450 heme domains, when immobilized in a didodecyldimethylammonium bromide film cast on an edge-plane graphite electrode....

7p tumor12 20-04-2013 46 3   Download