YPepsin vs Pepsinogen
Ob leeg pepsin thiab pepsinogen yog cov protein hauv keeb kwm thiab pom muaj nyob hauv cov kua txiv hmab txiv ntoo ntawm cov tsiaj. Txij li thaum, pepsinogen yog qhov ua ntej ntawm pepsin; Nws yog ib qho tsim nyog yuav tsum muaj pepsinogen nrog ib puag ncig acidic lossis yav tas los tsim pepsin los tsim pepsin hauv plab. Ob lub tebchaw no yog ib qho tseem ceeb rau kev ua tiav thawj kauj ruam ntawm kev zom cov protein. Thaum, pepsinogen, ib qho quav ib leeg peptide saw, hloov mus rau pepsin, muaj qee qhov kev hloov pauv hauv lub cev thiab tshuaj lom neeg ntawm cov protein.
Pepsin
Pepsin yog daim ntawv nquag ntawm pepsinogen uas hydrolyzes proteins thaum lub sijhawm zom zaub mov. Txhawm rau tsim pepsin los ntawm pepsinogen, nws yog ib qho tsim nyog yuav tsum muaj ib puag ncig acidic (pH< ~ 5) lossis muaj cov tshuaj pepsin yav dhau los. Pepsin yog ib qho enzyme proteolytic uas faib cov protein rau hauv cov proteoses, peptones, thiab polypeptides. Porcine pepsin A yog cov kws tshawb fawb tshaj plaws thiab muag muag pepsin, uas yog cais tawm ntawm lub plab mucosa ntawm npua.
Pepsin yog tsim los nrog 6 helical seem, thiab txhua ntu muaj tsawg dua 10 amino acids. Tsis tas li ntawd, nws muaj tsawg heev cov amino acid residues thiab 44 acidic residues. Vim li ntawd, nws ruaj khov heev ntawm pH tsawg heev. Tsis tas li ntawd, cov qauv tertiary complex thiab hydrogen bonds kuj txhawb nqa nws cov qauv acidic stability. Ib qho kev hloov pauv hauv daim ntawv cog lus nyob rau hauv pepsinogen molecule ua rau tsim pepsin nrog rau thaj tsam pH tsawg. Cov txheej txheem hloov dua siab tshiab muaj tsib kauj ruam. Thawj kauj ruam ntawm cov txheej txheem yog thim rov qab thaum tus so yog irreversible. Yog li ntawd, thaum nws dhau theem thib ob, cov protein tsis tuaj yeem rov qab mus rau pepsinogen.
YPepsinogen
Pepsinogen yog ib qho tsis muaj zog proenzyme uas yog siv los tsim pepsin rau kev zom cov protein. Nws muaj ib qho ntxiv 44 amino acids ntawm nws cov N-terminus uas tau tso tawm thaum lub sij hawm hloov. Muaj ob hom pepsinogen, uas yog; pepsinogen I thiab pepsinogen II, nyob ntawm qhov chaw zais cia.
Pepsinogen I yog zais los ntawm cov hlwb tseem ceeb, thiab pepsinogen II yog zais los ntawm cov qog pyloric. Kev tso tawm ntawm pepsinogen yog txhawb los ntawm vagal stimulation, gastrin, thiab histamine. Pepsinogen kuv feem ntau pom nyob rau hauv lub cev ntawm lub plab, qhov twg feem ntau acid yog secreted. Pepsinogen II feem ntau pom muaj nyob hauv ob lub cev thiab lub plab ntawm lub plab.
Pepsin thiab Pepsinogen yog dab tsi?
• Pepsin yog ib qho enzyme proteolytic, whereas pepsinogen yog proenzyme.
• Pepsin yog daim ntawv nquag ntawm pepsinogen thaum pepsinogen yog qhov tsis ua haujlwm ntawm pepsin.
• Tsis zoo li pepsin, pepsinogen yog zais los ntawm cov cell thiab cov qog pyloric.
• Pepsinogen hloov mus rau pepsin los ntawm hydrochloric acid lossis ua pepsin.
• Tsis zoo li pepsin, pepsinogen secretion yog stimulated los ntawm vagal simulation, gastrin, thiab histamine.
• Pepsinogen ruaj khov nyob rau hauv ob qho tib si nruab nrab thiab alkaline daws, qhov pepsin tsis yog.
• Tsis zoo li pepsinogen, pepsin tuaj yeem hydrolyze proteins.
• Pepsin tuaj yeem qhib tau los ntawm kev txo qis pH ntawm qhov nruab nrab, qhov pepsinogen tsis tuaj yeem.
