Lecithinyog ib qho tseem ceeb ntawm cov khoom siv roj ntsha uas muaj ntau yam kev ua haujlwm ntawm lub cev hauv tib neeg lub cev, xws li cov khoom tseem ceeb ntawm cov cell membranes, neurotransmitters, thiab lipid metabolism hauv daim siab, yog li nws tseem ceeb heev kom nkag siab txog nws cov synthesis. Nyob rau hauv tsab xov xwm no, tag nrho cov txheej txheem synthesis ntawm Lecithin yuav qhia los ntawm cov hauv qab no: phosphatidylcholine synthesis pathway, lecithin synthesis pathway, phospholipid synthesis pathway thiab fatty acid glycerol phosphate synthesis pathway.
1. Phosphatidylcholine synthesis txoj kev:
Lecithin, tseem hu ua lecithin, yog ib qho tseem ceeb phospholipid cov khoom muaj nyob rau hauv cov tsiaj thiab cov nroj tsuag kab mob. Hauv cov kab mob, Lecithin plays ntau yam haujlwm tseem ceeb ntawm lub cev, nrog rau cov qauv ntawm cov cell membrane, neurotransmission, cholesterol metabolism, thiab lwm yam.
Phosphatidylcholine yog ib qho tseem ceeb tshaj plaws ntawm Lecithin, uas muaj ntau heev hauv tib neeg lub cev. Lub biosynthesis ntawm phosphatidylcholine feem ntau ua tiav los ntawm kev hloov tshuaj methyl, thiab nws cov ncauj lus kom ntxaws yog raws li hauv qab no:
1.1. Phosphatidylacyldiacylglycerol (PA) tsim los ntawm fatty acids thiab glycerol yog phosphorylated los ntawm CDP-acylcholine (CDP-Choline) los tsim phosphorylcholine (PtdCho).
1.2. Tib lub sijhawm, methylation yog muab los ntawm SAM (S-adenosylmethionine) rau methylate methionylcholine (GPC) rau hauv rog -2-phosphoadenosylcholine (PC).
1.3. PtdCho thiab PC tsim phosphatidylinositol choline (PI-Cho) los ntawm kev sib pauv cov tshuaj tiv thaiv catalyzed los ntawm rog -1-phosphoinositide transferase.
1.4. PI-Cho ces hloov mus rau hauv phospho-inositol choline (IP-Cho) los ntawm dephosphorylation.
Cov saum toj no yog tag nrho cov synthesis txoj kev ntawm phosphatidylcholine, nyob rau hauv uas thawj thiab thib ob kauj ruam yog txoj kev phosphorylcholine (Kennedy txoj kev), uas feem ntau tshwm sim nyob rau hauv endoplasmic reticulum thiab Golgi lub cev; Qhov thib peb thiab plaub theem yog inositol phospholipids txoj kev, feem ntau nyob rau hauv lub cytoplasm thiab nyob rau hauv eosinophilic lub cev. Lub synthesis ntawm phosphatidylcholine yuav tsum muaj kev koom tes ntawm ntau yam enzymes thiab coenzymes, xws li CDP acylase, SAM adenylase, phosphatidylinositolase, thiab dephosphatase.
2. Lecithin synthesis txoj kev:
Lecithin yog ib qho tseem ceeb ntawm cov roj ntsha lipid uas muaj dav hauv cov kab mob, thiab muaj lub luag haujlwm tseem ceeb hauv kev saib xyuas ntawm cell membrane qauv thiab kev ua haujlwm, neurotransmission, thiab lipid metabolism. Nws cov khoom tseem ceeb suav nrog phosphorylcholine, phosphorylacetylcholine, thiab phosphorylcreatine, ntawm cov phosphorylcholine muaj cov ntsiab lus siab tshaj plaws, suav txog ntau tshaj li ib nrab ntawm tag nrho cov lecithin. Cov txheej txheem synthesis ntawm lecithin suav nrog ntau txoj hauv kev metabolic thiab kev sib koom ua ke ntawm ntau yam enzymes, uas txawv ntawm ntau hom cell thiab cov ntaub so ntswg sib txawv. Lub ntsiab synthesis ntawm lecithin yuav tham hauv qab no.
2.1. Glycerophosphate txoj kev (GPAT txoj kev):
Txoj kev glycerophosphate yog thawj kauj ruam ntawm lecithin synthesis, thiab nws cov txheej txheem feem ntau suav nrog cov kauj ruam hauv qab no: glycerol triphosphate (G3P) ua ke nrog fatty acids los tsim acyl glycerophosphate (LPA), thiab LPA ntxiv phosphatidic acid (PA) los ntawm decarboxylation cov tshuaj tiv thaiv, PA Reduction tsim CDP-acylglycerol (CDP-DAG), thiab CDP-DAG thiab choline, ethanolamine thiab lwm yam substrates ntxiv synthesize lecithin los ntawm txoj kev inositol phospholipid. GPAT enzyme yog tus nqi txiav txim siab enzyme ntawm glycerol phosphate txoj hauv kev, thiab nws cov catalysis yog acylate glycerol triphosphate thiab fatty acid los tsim LPA. Kev muab cov substrates xws li choline yuav tsum tau nqa tawm los ntawm ib qho ntawm ob txoj hauv kev ntawm "inositol phosphatidylation" thiab "ornithine phosphatidylation".
2.2. Inositol phospholipid txoj kev:
Txoj hauv kev inositol phospholipid yog ib txoj hauv kev tseem ceeb ntawm kev sib txuas ntawm lecithin, thiab nws txoj hauv kev muaj feem xyuam rau cov cell membrane diphosphate mannitol txoj kev. Kev sib xyaw ntawm inositol phospholipids feem ntau suav nrog ob kauj ruam hauv qab no: phosphatidylation cov tshuaj tiv thaiv ntawm choline lossis inositol phosphate nrog acylglycerol phosphate los tsim phosphoglycerol choline (PGC) lossis phosphoglycerol inositol (PGI), thiab tom qab ntawd los ntawm kev hloov pauv hauv inositol (PGI) Transferase (PGT ) hloov phosphoglycerol choline los yog phosphoglycerol inositol mus rau CDP-DAG molecule los tsim ib tug ua tiav lecithin molecule. phosphorylcholine synthesized los ntawm inositol phospholipid txoj hauv kev suav txog li 20 feem pua ntawm tag nrho cov lecithin.
2.3. Ornithine phospholipid txoj kev:
Txoj kev ornithine phospholipid yog txoj hauv kev tseem ceeb rau kev sib txuas ntawm ornithine phospholipids. Txoj kev no yog nyob ntawm hydrolysis ntawm ornithine nyob rau hauv lub cell mus rau ammonia thiab catalysis ntawm carbon dioxide los tsim pyruvic acid thiab oxalic acid, thiab ces acyl hloov cov tshuaj tiv thaiv ntawm oxalic acid thiab acylglycerol phosphate kom tau phosphoglyceryl oxalic acid (PGS). Tom qab ntawd, PGS hloov cov phosphorus pawg mus rau CDP-DAG molecule los ntawm ob lub enzyme-catalyzed cov tshuaj tiv thaiv (PSD thiab PSS), tsim kom muaj tag nrho cov lecithin molecule. phosphorylcholine synthesized los ntawm ornithine phospholipid txoj hauv kev suav txog li 10 feem pua ntawm tag nrho cov lecithin.
3. Synthesis txoj kev ntawm phospholipids:
Lecithin (phospholipid) yog phospholipid ntau heev, nws cov khoom tseem ceeb yog phosphoglycerides thiab choline, thiab tuaj yeem siv dav hauv zaub mov, tshuaj, tshuaj tua kab thiab lwm yam. Muaj ntau ntau txoj kev npaj ntawm Lecithin, feem ntau yog siv cov tshuaj thiab cov txheej txheem lom.
Cov txheej txheem tshwj xeeb yog raws li hauv qab no:
1. Cafestol thiab Amino Acids:
Hauv kev lag luam fermenter, cell substrate cafestol thiab amino acid ntxiv, thiab tom qab fermentation cov tshuaj tiv thaiv, ib tug fermentation kua uas muaj cafestol thiab amino acid yog generated.
2. Phosphorylation:
Ntxiv qhov tsim nyog ntawm phosphoric acid rau fermentation broth, thiab siv phosphorylase ntxiv phosphoric acid rau glycerol los ua glycerophosphate. Ntawm lawv, txoj haujlwm ntawm phosphorylase yog ntxiv phosphoric acid rau cafestol thiab amino acids.
3. Tsim fatty acid ethanolamine:
Glycerophosphate thiab fatty acid ethanolamine reacted los ntawm acylase los ua Lecithin. Ntawm lawv, kev ua haujlwm ntawm acylase yog muab cov roj ntsha nrog phosphoglyceride lossis cawv amine los ua Lecithin.
4. Enzyme immobilization technology:
Cov thev naus laus zis tso cai rau ntau cov enzymes tsim tawm thiab tuaj yeem rov qab siv dua, ua rau cov txheej txheem tsim cov Lecithin ntau dua. Lub enzyme yog immobilized ntawm kaolin kom hloov fatty acid pawg mus rau ethanolamine los tsim Lecithin, uas muaj zoo reusability.
Phospholipid yog ib qho ntawm cov khoom tseem ceeb tshaj plaws ntawm Lecithin, thiab nws txoj kev sib txuas nrog cov substrates sib txawv. Phosphoric acid (pentose phosphate pathway) yog cov substrate 1-hydroxyglyceric acid uas ua los ntawm cov piam thaj metabolism; substrate phosphatidic acid yog tsim los ntawm acidification; CDP-choline tuaj yeem tau los ntawm cov tshuaj tiv thaiv methylation; Cov substrates pyruvate thiab methylvalonate yog tsim; cov amino acids lysine thiab leucine tuaj yeem tau los ntawm decarboxylation; cov substrates potassium thiab methionine tuaj yeem siv los ua cov tshuaj tiv thaiv substrates uas catalyze ob-hauv-ib cov tshuaj tiv thaiv ntawm CDP choline phosphate.
4. Synthesis txoj kev ntawm fatty acid glycerol phosphate:
Fatty acid glycerol phosphate synthesis pathway yog lwm txoj hauv kev rau biosynthesis ntawm Lecithin, uas tsis muaj choline, nws cov substrates tseem ceeb yog fatty acids thiab tartrate, thiab triglyceride tuaj yeem tau los ntawm catalysis ntawm acyl inarcosyl synthase. Tom qab ntawd, los ntawm kev ua ntawm triglyceride acyltransferase, phosphate daim ntawv cog lus yog tsim los ntawm 2-hydroxyglycerol thiab tartrate los tsim cov qauv molecular ntawm fatty acid glycerol phosphate, uas yog precursor ntawm Lecithin.
Hauv cov ntsiab lus, cov txheej txheem hluavtaws ntawm lecithin muaj xws li phosphatidylcholine hluavtaws txoj kev, lecithin hluavtaws txoj kev, phospholipid hluavtaws txoj kev thiab fatty acid glycerol phosphate synthetic pathway. Ntawm lawv, txoj hauv kev phosphatidylcholine synthesis thiab lecithin synthesis txoj kev zoo ib yam, thiab ob qho tib si hnov los ntawm CDP-chloroacetic acid intermediate; phospholipid synthesis txoj kev siv ntau lub substrates, nrog rau cov substrates uas tsim los ntawm qab zib metabolism thiab oxidation txoj kev. Substrates thiab substrates tsim los ntawm decarboxylation cov tshuaj tiv thaiv; Lub luag haujlwm tseem ceeb ntawm fatty acid glycerol phosphate synthesis txoj hauv kev yog los tsim cov qauv ua ntej molecular ntawm Lecithin.