Qhov sib txawv tseem ceeb ntawm PFK-1 thiab PFK-2 yog PFK-1 catalyzes hloov pauv ntawm fructose 6-phosphate thiab ATP rau fructose 1, 6-bisphosphate thiab ADP thaum PFK-2 catalyzes lub synthesis ntawm fructose 2., 6-bisphosphate los ntawm fructose 6-phosphate.
Phosphofructokinase-1 (PFK-1) thiab phosphofructokinase-2 (PFK-2) yog ob lub enzymes. PFK-1 yog glycolytic enzyme uas catalyzes cov tshuaj tiv thaiv ntawm fructose 6-phosphate, hloov mus rau fructose 1, 6-bishosphate. Nws yog tus nqi-txheej theem ntawm glycolysis. Thaum cov piam thaj siab siab, thiab yuav tsum tswj glycolysis, PFK-2 catalyzes cov synthesis ntawm fructose 2, 6-bisphosphate los ntawm fructose 6-phosphate. Fructose 2, 6-bisphosphate yog ib qho muaj zog allosteric activator ntawm PFK-1 txhawm rau txhim kho qhov kev puas tsuaj ntawm cov piam thaj. PFK-2 tsis yog glycolytic enzyme. Tab sis, ob qho tib si PFK-1 thiab PFK-2 ua rau tib lub substrate.
PFK-1 yog dab tsi?
PFK-1 yog thawj qhov kev cog lus enzyme hauv glycolysis. Qhov tseeb, nws yog tus nqi txwv enzyme ntawm glycolysis. Nws catalyzes hloov pauv ntawm fructose 6-phosphate rau fructose 1, 6-bisphoshate. PFK-1 siv ATP rau cov tshuaj tiv thaiv no. Yog li, PFK-1 cuam tshuam los ntawm ATP concentration. Qhov inhibition ntawm PFK-1 los ntawm ATP yog ib feem ntawm qhov kev tawm tswv yim tsis zoo uas tswj glycolysis flux nyob rau hauv lub xeev aerobic. Tsis yog los ntawm ATP, PFK-1 kev ua haujlwm yog tswj hwm los ntawm ntau lwm cov molecules, suav nrog fructose 2, 6-bisphosphate, AMP thiab citrate.
Daim duab 01: PFK-1
Fructose 2, 6-bisphosphate yog lub zog allosteric activator ntawm PFK-1. Ntawm lub cev muaj zog, PFK-1 tseem tsis muaj zog. Thaum nws cuam tshuam nrog fructose 2, 6-bisphoshate, nws ua haujlwm thiab txhawb nqa txoj hauv kev glycolytic kom nce qabzib. Flux nyob rau hauv cov kev taw qhia ntawm glycolysis yog heev nce los ntawm fructose 2, 6-bisphosphate vim nws muaj peev xwm ntawm allosteric activation ntawm PFK-1. Hauv ib txoj kev zoo sib xws, AMP kuj ua raws li kev ua haujlwm zoo los ua kom PFK-1. Hauv qhov sib piv, citrate ua raws li allosteric inhibitor ntawm PFK1. Magnesium ua raws li qhov sib koom ua ke rau PFK-1.
PFK-2 yog dab tsi?
Fructose 2, 6-bisphosphate yog cov metabolite uas tswj glycolysis thiab gluconeogenesis. PFK-2 los yog phosphofructokinase-2 yog lub enzyme uas catalyzes lub synthesis ntawm fructose 2, 6-bisphosphate los ntawm fructose 6-phosphate. Zoo ib yam li PFK-1, PFK-2 ua rau tib lub substrate. Txawm li cas los xij, tsis zoo li PFK-1, PFK-2 kev ua haujlwm tsis cuam tshuam los ntawm ATP concentration. Phosphoenolpyruvate thiab citrate tuaj yeem cuam tshuam cov enzyme no, thaum inorganic orthophosphate tuaj yeem txhawb kev ua haujlwm ntawm PFK-2.
Daim duab 02: PFK-2
Structurally, PFK-2 tshwm sim nrog fructose-2, 6-bisphosphatase raws li bifunctional enzyme abbreviated li PFK-2 / FBPase-2. PFK-2 phosphorylates fructose 6-phosphate siv ATP. Ntawm qhov tod tes, FBPase-2 dephosphorylates fructose 2, 6-bisphosphate los tsim fructose 6-phosphate thiab Pi. Yog li, PFK-2 muaj ob qho tib si kinase thiab phosphatase cov haujlwm. Thaum cov piam thaj siab siab, insulin nce kinase kev ua haujlwm ntawm PFK-2 enzyme los ua kom muaj zog ntxiv ntawm fructose 2, 6-bisphosphate. Nws txhawb nqa glycolysis vim kev ua haujlwm ntawm PFK-1 los ntawm fructose 2, 6-bisphosphate. Hauv qhov sib piv, thaum phosphatase kev ua ntawm PFK-2 tau qhia, nws rhuav tshem fructose 2, 6-bisphosphate rov qab rau hauv fructose 6-phosphate, stimulating gluconeogenesis thiab inhibiting glycolysis.
Qhov Zoo sib xws ntawm PFK1 thiab PFK-2 yog dab tsi?
- PFK-1 thiab PFK-2 yog ob lub enzymes.
- Lub substrate ntawm PFK-1 thiab PFK-2 enzymes yog tib yam: fructose 6-phosphate.
- Ob lub enzymes tseem ceeb hauv kev tswj hwm glycolysis.
- Cov tshuaj tiv thaiv catalyzed los ntawm ob qho enzymes tawm los ntawm ADP los ntawm ATP.
- Citrate tuaj yeem cuam tshuam ob qho enzymes.
Qhov txawv ntawm PFK-1 thiab PFK-2 yog dab tsi?
PFK-1 catalyzes hloov pauv ntawm fructose 6-phosphate rau fructose 1, 6-bisphosphate. Hauv qhov sib piv, PFK-2 catalyzes hloov pauv ntawm fructose 6-phosphate rau fructose 2, 6-bisphosphate. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm PFK1 thiab PFK-2. Tsis zoo li PFK-1, PFK-2 muaj ob qho tib si kinase thiab phosphatase kev ua haujlwm; yog li ntawd nws yog ib tug bi-functional enzyme. Ntxiv mus, fructose 2, 6-bisphosphate yog ib qho muaj zog allosteric activator ntawm PFK-1, thaum PFK-2 catalyzes cov synthesis ntawm fructose 2, 6-bisphosphate. Yog li, qhov no yog lwm qhov sib txawv ntawm PFK-1 thiab PFK-2. Qhov tseem ceeb tshaj plaws, PFK-1 kev ua haujlwm cuam tshuam los ntawm ATP, thaum PFK-2 kev ua haujlwm tsis cuam tshuam los ntawm ATP concentration.
Cov infographic hauv qab no teev qhov sib txawv ntawm PFK-1 thiab PFK-2 hauv daim ntawv teev npe rau ib sab ntawm kev sib piv.
Summary – PFK-1 vs PFK-2
PFK-1 catalyzes hloov pauv ntawm fructose 6-phosphate thiab ATP rau fructose 1, 6-bisphosphate thiab ADP. PFK-2 catalyzes cov synthesis ntawm fructose 2, 6-phosphate los ntawm fructose 6-phosphate. Kev ua haujlwm PFK-1 cuam tshuam los ntawm ATP concentration. Hauv qhov sib piv, PFK-2 tsis cuam tshuam los ntawm ATP concentration. Qhov tseem ceeb tshaj plaws, PFK-2 muaj ob qho kev ua kinase thiab phosphatase; yog li ntawd nws yog ib tug bi-functional enzyme. PFK-1 tsis yog bi-functional enzyme. Tsis tas li ntawd, PFK-1 yog qhov txwv tsis pub muaj enzyme ntawm glycolysis, thaum PFK-2 tsis suav tias yog glycolytic enzyme. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm PFK-1 thiab PFK-2.
