Please enable JavaScript.

Coggle requires JavaScript to display documents.

Carbohydrates and Glycobiology (常見單糖與縮寫 (abequose:Abe, arabinose:Ara,…

- - - - intracellular targeting of proteins
      - tissue development
      - cell-cell devolopment
      - extracellular signals
    - - Neu5Ac(A sialic acid)
        
        在血漿蛋白糖(i.e. ceruloplasmin血漿銅藍蛋白)的末端residue
        
        保護蛋白不被吸收或是在肝臟中被分解
        
        肝細胞膜上有lectin(asialoglycoprotein去唾液酸糖蛋白 receptors)專一結合沒有被末端Neu5Ac保護的寡糖
      - RBC去除
        
        新的紅血球糖蛋白的寡糖上有Neu5Ac
    - - protein receptor read the sugar code
      - mediate many biological processes
      - usu. 包含兩個以上的碳水化合物單元結合位
      - 有些lectin組成的寡聚體上有多個結合位
      - example
        
        wheat germ agglutinin
        
        GlcNAc β(1->4) GlcNAc β(1->4) GlcNAc
        
        peanut lectin
        
        Gal β(1->3) GlcNAc
        
        phytohemagglutinin
        
        Man
        
        β(1->6) GlcNAc β(1->4) Gal
        
        β(1->2) GlcNAc β(1->4) Gal
    - - 與P-selectin 結合方便滾動
      - 與integrin 結合:adhesion
      - 在發言處extravasation滲出
    - - 是oligosaccharide Le^b
      - O型血 determinant
      - gastric ulcer 在O型血的人中比較多
    - - 流感病毒受器
      - 與sialic acid residues/neuraminidase 結合
      - 為了釋放更多病毒顆粒
    - - viral sialidase
      - inhibited by Tamiflu/Relenza(sugar analogs)
        
        compete with host cells' oligosaccharidase for binding
        
        prevent the release of virus
    - - marker for proteins to lysosome
        
        glycosome(lysosome to be)need phosphate marker in the cis golgi
        
        phosphotransferase
        
        adds a phospho-N-acetyl glucosamine to the 6-OH group of a mannose
        
        UDP-GlcNAc->UMP
        
        C6-OH->C6-O-phosepho-GlcNAc
        
        I-cell patient 缺少Phosphotransferase
        
        phosphodiesterase
        
        上水脫去GlcNAc
        
        去除新加入的糖產生mannose 6-phosphate
        
        I-cell(inclusion in lysosome with GAGs and glycolipids)patients deficient in phosphotransferase
        
        Inclusion-cell (I-cell) disease
        
        mucolipidosis II (ML II)
        
        臨床症狀與黏多糖儲積症第一H型(hurler syndrone)相似
        但發病年齡較早，無尿液黏多醣代謝物
        
        纖維芽母細胞有細胞質包含體存在(I cell)
        
        lysosomal storage disease
        
        Mannose 6 phosphate serves as a marker targeted to lysosomes
        
        當marker 缺乏時，蛋白質會在細胞外面分泌(cf. default 蛋白質會穿越高基氏體)
        
        Lysosomes cannot function without these proteins
        
        protein function as catabolic enzymes for the normal breakdown of substances (e.g. oligosaccharides, lipids, and glycosaminoglycans) in various tissues throughout the body (i.e. fibroblasts)
        
        inclusion cells are abnormal fibroblasts having a large number of dark inclusions in the cytoplasm of the cell (mainly in the central area)
        
        inclusions are of various fats, proteins, carbohydrates, pigments and other insoluble
        
        M6P receptor lectin binds M6P-tagged-proteins,targeted to lysosome
        
        oligosaccharides in recognition and adhesion
        
        unique structure (strings of hexagon)
        
        與糖酯、糖蛋白組合
        
        2 more items...
        
        感染動物的病毒與細胞表面糖蛋白結合(感染第一步)
        
        細菌毒素(toxin)(cholera and pertussis toxin)與糖酯結合
        
        有些細菌(H. pylori)直接和糖蛋白結合colonization
        
        selectin(lectin)in plasma membrane mediate cell-cell interactions
        
        在微血管內皮的嗜中性球
        
        M6P receptor/lectin of the trans golgi complex binds to the oligosaccharide of lysosomal enzymes ,targeting them for transfer into the lysosome.
- - - - furanose
        
        五角環
      - 六角環
        
        honey is β-D-fructopyranose
    - - 三碳
        
        D-glycrealdehyde
      - 四碳
        
        D-erythrose
        
        D-threose
      - 五碳
        
        D-ribose
        
        D-arabinose
        
        D-xylose
        
        D-lyxose
      - 六碳
        
        D-aldose
        
        D-altrose
        
        D-glucose
        
        D-mannose
        
        D-gulose
        
        D-idose
        
        D-galactose
        
        D-talose
    - - 三碳
        
        dehydroxyacetone
      - 四碳
        
        D-erythrulose
      - 五碳
        
        D-ribulose
        
        D-xylulose
      - 六碳
        
        D-psicose
        
        D-fructose
        
        D-sorbose
        
        D-tagatose
- - - - O-glycosidic bond
      - N-glycosidic bond
- - - - 二價銅變一價銅
    - - 一價銀變銀金屬
- - - - 菲林反應
        
        兩個二價銅被還原成一價銅
        
        cuprous oxide 沉澱
  - - - lactose Gal(β1->4)Glc
    - - sucrose Fru(β2-1α)Glc
        
        sucrase=invertase ->invert sugar
        found in intestines
        breaks down sucrose to fructose and glucose
      - trehalose海藻糖 Glc(α1-1α)Glc
        
        昆蟲血淋巴的主要成分
- - - - 大部分動物沒有β1->4的酵素
      - 每年地球上10^15公斤製造、分解
      - D-glucose β1->4
- - - - GlcNAc、GalNAc
    - - D-gluconic 、L-iduronic acid
      - hyaluroonate
        
        up to 50000 repeats of the basic disaccharide unit 分子量接近百萬
        
        滑膜關節液
        
        眼球玻璃體液
        
        關節肌腱的胞外基質
        
        其他非hyaluronate的GAGs
        
        共價鍵結到特定的連結蛋白
        
        form proteoglycans
        
        比較短
  - - - GlcA β(1->3) GlcNAc β(1->4)
      - 一鏈50000個雙糖
    - - GlcA β(1->3) GlcNAc4SO2- β(1->4)
      - 一條鏈20-60雙糖
    - - Gal β(1->4) GlcNAc6SO2- β(1->3)
      - 25雙糖一條鏈
      - 非uronic acids(糖醛酸)
      - 角膜、軟骨、骨骼、角、頭髮、蹄、爪、指甲
    - - β1->3
      - pliability of skin柔韌性
      - blood vessels
      - heart valve
    - - fractionated heparan sulfate
      - 抗凝血劑
        
        與prothrombin3相連
      - β1->4
      - 生物具分子中負電密度最高
      - FGF1、FGFReceptor、GAG（heparin）共結晶
  - - - mucopolysaccharidoses(MPS)
        
        MPS1
        
        缺乏α-L-iduronidases,無法切開dermatan 和heparan sulfate
        
        MPS2
        
        缺乏iduronate sulfate sulfatase無法切開herparan sulfate
        
        MPS4A
        
        缺乏N-Acetylgalactosamine 6-sulfate sulfatase無法切開keratin sulfate
- - - - syndecan
        
        連接一個跨膜core protein
        
        heparan sulfate
        
        unmodified NA
        
        7 雙糖單元NS
        
        連結特定蛋白
        
        3～8雙糖
        
        GlcNS GlcA GlcNS GlcA GlcNS IdoA GlcNS IdoA GlcNS IdoA GlcNS IdoA GlcNS IdoA
        
        modifications
        
        confromational activation(-)
        
        凝血因子Xa 接在AT(antithrombin)上面促進與NS上特定五糖結合以避免凝血
        
        增強蛋白質
        間交互作用
        
        AT 和thrombin接在鄰近的NS上連接在一起，避免凝血
        
        coreceptor for
        extracellular ligands
        
        FGF(fibroblast growth factor)和FGFReceptor雙元體與NS作用，將寡聚體聚合在一起並增加FGF的效用
        
        cell surface localization/concentration
        
        硫酸肝素高密度負電賀吸引正電脂蛋白脂肪酶(lipoprotein lipase)並用電穩定性及序列專一性與NS domains
        作用
        
        Increased
        
        heparan sulphate與heparin
        
        GlcA GlcN IdoA
        
        heparin sulphate
        
        GlcA多
        
        sulfated(較弱)(-)
        
        heparan-sulphate GAG chains tend to exists as proteoglycan component
        ->tethered to a protein core
        
        在細胞表面表現
        
        2 more items...
        
        heparin
        
        IdoA多
        
        sulfated(較強)(-)
        
        與組織胺(histamine)共同釋放
        
        肥大細胞degranulation
        
        與蛋白核解離可做自由GAG
        
        4member
        
        chondroitin sulfate
      - glypican
        
        lipid anchor 連接膜
        
        GPI Anchor
        
        derivative of membrane lipid phosphatidylinositol
        
        globular domain with disulfide bond*2
        
        heparin sulfate
        
        7 member
      - protease
        
        cut close to membrane surface
        
        release syndecan ectodomains
        
        breaks the connection to the membrane lipid
        
        release glypicans
    - - hyaluronan aggrecan form huge Mr>2*10^8 非共價聚合
      - 可抓住1000被自身重量的水分
        
        lubrication
      - low friction material
      - covers joints surface: 關節軟骨
        
        降低摩擦
        
        負載平衡
      - hyaluronan巨棒以link protein連接aggrecan protein 短棒，短棒上接keratan sulfate和chondroitin sulfate
      - 細胞膜內有actin filament以integrin連結出膜外上面有proteoglycan、fibronectin、cross-linked fibers of collagen
  - - - carbohydrate attached via anomeric carbon
    - - 可能分泌出去或是停留在膜上的糖蛋白，上面有很大數目的O-link 寡糖鏈
      - most secretions, slipperiness
      - 蛋白分解的計時系統
    - - O-linked
        
        Neu5Ac GalNAc加上Ser/Thr
      - N-linked
        
        GlcNA接Asn
      - 決定是N-linked或是o-linked的是後面接上的氨基酸
  - - - 寡糖抗原結構
        
        O
        
        α(1->2) Fuc
        
        A
        
        Gal fork
        
        α(1->3)GalNAc
        
        α(1->2) Fuc
        
        B
        
        Gal fork
        
        α(1->3)Gal
        
        α(1->2) Fuc
        
        共同結構
        
        Gal β(1->3) GlcNAc β(1->3) Gal fork α(1->2) Fuc
        
        identical in all but 4/354 positions
    - - O-specific chain +core+Lipid A
- - - - endoglycosidase（糖類內切酶）
        切出寡糖混合物
        
        分離寡糖方法有三
        1.離子交換層析
        2.凝膠過濾Gel filtration
        3.用與lectin的親和度層析
        
        與強酸水解
        產生單糖
        
        高效能液態層析
        氣液態層析
        得到單糖分子混合物
        可分析單糖種類數量
        
        以CH3I（強鹼）過量甲基化
        得到甲基化碳水化合物
        
        酸中水解產生單糖（在糖苷鍵以外的所有-OH甲基化）
        可辨認糖苷鍵的位置
        
        以酵素水解特定糖苷鍵
        產生小寡糖
        
        由混合物分辨率分離
        寡糖用甲基化或是酵素分析控制
        判斷單糖序列、糖苷鍵構型
        
        NMR或質譜儀