Qhov Tseem Ceeb Qhov txawv - Alpha vs Beta Amylase
Ob leeg Alpha thiab Beta amylase yog cov enzymes uas catalyze hydrolysis ntawm starch rau hauv qab zib. Alpha amylase ua haujlwm ntawm qhov chaw tsis sib xws raws cov hmoov txhuv nplej siab thaum Beta amylase ua haujlwm los ntawm qhov tsis txo qhov xaus txhawm rau pab txhawb kev tawg ntawm polysaccharides loj. Qhov no yog qhov sib txawv tseem ceeb ntawm Alpha amylase thiab Beta amylase. Kev sib txawv ntxiv yuav tau tham hauv kab lus no
Alpha Amylase (α-amylase) yog dab tsi?
Amylase yog ib qho enzyme uas pab cuam tshuam cov alpha-txuas polysaccharides loj xws li cov hmoov txhuv nplej siab thiab glycogen rau cov piam thaj thiab m altose. Alpha amylase yog hu ua 1-4-a-D-glucan glucanohydrolase (EC 3.2.1.1.) raws li lub npe ntawm lub luag haujlwm ntawm enzyme. Nws muaj nyob rau hauv tib neeg thiab lwm yam tsiaj thiab kuj nyob rau hauv cov noob uas muaj starch. Nws kuj tseem zais los ntawm qee cov kab mob (ascomycetes, mbasidiomycetes) thiab cov kab mob (bacillus).
Hauv tib neeg lub cev, amylase tseem ceeb tshaj plaws hauv cov kua txiv qaub thiab qaub ncaug. Pancreatic α-amylase random cleaves α (1, 4) glycosidic linkages ntawm amylose kom tawm los dextrin, m altose lossis m altotriose. Amylase pom hauv cov qaub ncaug yog hu ua ptyalin thiab nws tawg cov hmoov txhuv nplej siab rau hauv m altose thiab dextrin.
Alpha amylase yog glycoprotein; ib leeg polypeptide saw ntawm txog 475 residues muaj ob pawg thiol dawb, plaub disulfide txuas hniav, thiab muaj Ca2+. Nws muaj nyob rau hauv ob daim ntawv uas yog PPAI thiab PPAII
Phenolic tebchaw, qee cov nroj tsuag rho tawm, thiab urea thiab lwm yam amide reagents tuaj yeem suav tias yog cov inhibitors rau Alpha amylase
Alpha amylase tau tshawb pom los ntawm Anselme Payen hauv xyoo 1833. Alpha amylase yog siv hauv ethanol ntau lawm txhawm rau txhawm rau cov hmoov txhuv nplej siab rau hauv fermentable qab zib. Nws kuj yog siv nyob rau hauv siab fructose pob kws phoov ntau lawm thiaj li yuav tsim luv luv saw oligosaccharides. Alpha amylase (tseem hu ua astermamyl) ua los ntawm Bacillus licheniform tshwj xeeb yog siv hauv cov hmoov txhuv nplej siab tshem tawm cov tshuaj ntxuav tes.
Human salivary alpha-amylase
Beta Amylase (β-amylase) yog dab tsi?
Beta amylase yog ib qho exoenzyme tseem hu ua 1-4-a-D- glucan m altohydrolase (EC 3.2.1.2.) uas pab txhawb cov hydrolysis ntawm (1->4)-alpha-D glucosidic linkages hauv polysaccharides txhawm rau tshem tawm successive m altose units los ntawm qhov tsis txo qhov kawg ntawm cov chains. Yeej, nws ua rau cov hmoov txhuv nplej siab, glycogen, thiab qee cov polysaccharides.
Beta amylase feem ntau pom muaj nyob hauv cov noob ntawm cov nroj tsuag siab dua, kab mob thiab cov fungi. Feem ntau ntawm β-amylase yog monoeric enzymes; Txawm li cas los xij, tetrameric amylase hauv cov qos yaj ywm qab zib muaj plaub lub subunits zoo ib yam. Txhua lub subunit muaj 8-thaj cheeb tsam. Cys96 nyob ntawm qhov nkag ntawm thaj av no. Ib cheeb tsam me me yog tsim los ntawm cov voj voog ntev ntev los ntawm β-strands.
Cov hlau hnyav, iodoacetamide, ascorbate, cyclohexaamylose thiab sulfhydryl reagents ua inhibitors rau Beta amylase.
Beta amylase yog siv rau hauv fermentation hauv brewing thiab distilling kev lag luam, thiab saccharification ntawm liquefied starch.
YBarley Beta-Amylase
Qhov txawv ntawm Alpha thiab Beta Amylase yog dab tsi?
Site of Hydrolysis
Alpha amylase: Alpha amylase ua rau ntawm qhov chaw sib txawv raws cov hmoov txhuv nplej siab.
Beta amylase: Beta amylase ua los ntawm tsis txo qhov kawg txhawm rau txhawm rau txhawm rau txhawm rau loj polysaccharides.
khoom
Alpha amylase: Alpha amylase tuaj yeem pom nyob rau hauv tib neeg thiab qee cov tsiaj nyeg xws li hauv qee cov nroj tsuag thiab fungi.
Beta amylase: Beta amylase tsis tuaj yeem pom hauv tib neeg lossis tsiaj.
Kev ua haujlwm
Alpha amylase: Alpha amylase yog xav tias ua sai dua Beta amylase.
Beta amylase: Beta amylase tau xav tias qeeb dua Alpha amylase.
Status in Seed Germination
Alpha amylase: Alpha amylase tshwm sim thaum pib germination.
Beta amylase: Beta amylase muaj nyob rau hauv daim ntawv tsis muaj zog ua ntej germination.
Type
Alpha amylase: Alpha amylase muaj nyob rau hauv ob daim ntawv.
Beta amylase: Beta amylase muaj nyob hauv ib daim ntawv.
Gene uas Encode rau Enzyme
Alpha amylase: Tib neeg Alpha amylases raug encoded los ntawm ob loci amy1A, amy1B, amy1C (salivary) thiab amy2A, amy2B (pancreatic).
Beta amylase: Beta amylase yog encoded los ntawm amyB.
Molecular Nyhav
Alpha amylase: Molecular hnyav (ob hom) txawv ntawm 51kDa txog 54kDa.
Beta amylase: Molecular hnyav ntawm Beta amylase yog 223.8kDa.
zoo pH
Alpha amylase: Qhov zoo tshaj pH yog 7.
Beta amylase: pH txawv ntawm 4 txog 5.
Isoelectric Point
Alpha amylase:
PPAI 7.5
PPAII 6.4
Beta amylase: 5.17
Extinction Coefficient
Alpha amylase: 133, 870 cm-1 M-1
Beta amylase: 388, 640 cm-1 M-1
