Glycocalyx yog ib qho nyuaj supra-membrane complex uas tsim ib lub plhaub nyias nyob rau saum npoo ntawm cov plasma membrane ntawm cov tsiaj hlwb thiab cov kab mob cytoplasmic membranes. Lub sij hawm los ntawm kev sib txuas ntawm Greek thiab Latin lo lus glykys callum, uas txhais tau tias "qab zib tuab daim tawv nqaij". Tseeb tiag, glycocalyx ua raws li cov cell membrane ntxiv thiab yog tsim los ntawm cov molecules ntawm carbohydrate xwm, tab sis tsis zoo li cov plasma membrane, nws muaj ib tug fleecy es tsis yog ib tug nruam qauv.
yam ntxwv dav dav
Glycocalyx yog ib qho kev tiv thaiv ntxiv rau ntawm lub xovtooj ntawm tes, tsim los ntawm cov molecules ntawm cov proteins, carbohydrates thiab lipids txuas rau CPM, nrog rau cov txheej txheem ntawm cov protein nyob hauv daim nyias nyias. Lub hauv paus ntawm lub cytological npog yog lub network ntawm glycosides (glycoproteins thiab proteoglycans).
YogYog li, glycocalyx yog lub plhaub uas muaj nqi heev uas muaj cov khoom noj carbohydrate, uas yog kev sib xyaw ntawm cov tshuaj lom neeg macromolecules cuam tshuam nrog daim nyias nyias. Cov txheej no ua haujlwm ntxiv qhov thaiv ntawm lub xovtooj ntawm tes thiab ib puag ncig thiab ua haujlwm ntau yam, uas tau muab faib ua kom ruaj khov, tiv thaiv thiab tshwj xeeb.
Glycocalyx yog yam ntxwv nkaus xwb rau cov kab mob prokaryotic thiab tsiaj txhu. Cog cell membranes tsis tsim ib lub plhaub.
Functions
Cov txheej txheem tag nrho ntawm kev ua haujlwm ntawm glycocalyx hauv cov hlwb thiab ntawm cov ntaub so ntswg ntawm macroorganisms tam sim no tsis tau txhais. Txawm li cas los xij, nws twb tau tsim muaj txheej txheem no:
- koom nrog hauv cov teeb liab kis los ntawm ib puag ncig extracellular mus rau ib puag ncig intracellular;
- tiv thaiv cov cytoplasmic membrane los ntawm kev ntxhov siab thiab kev cuam tshuam rau txhua yam;
- muab cov khoom nplaum rau qee lub hlwb;
- ua raws li kev lees paub.
Hauv cov kab mob, glycocalyx muab txuas rau saum npoo, tiv thaiv kom tsis txhob ya raws thaum nws nkag mus rau qhov chaw qhuav, thiab tiv thaiv kev ua ntawm cov tshuaj tua kab mob. Hauv cov kab mob, txheej txheej no tuaj yeem tiv thaiv lub cev tiv thaiv kab mob los ntawm kev kuaj pom tus kab mob.
YBiochemical muaj pes tsawg leeg thiab qauv
Glycocalyx suav nrog:
- proteoglycans (chains ntawm glycosaminoglycans txuas nrog cov tub ntxhais protein) - muaj cov syndicans, glypicans, mimecan, perlacan thiab biglycans;
- glycosaminoglycans (linear disaccharide polymers ntawm uronic acid thiab hexosamine) - los ntawm 50-90% yog tsim los ntawm heparan sulfate, thiab tseem suav nrog dermatan sulfate, chondroitin sulfate, keratan sulfate thiab hyaluronan;
- glycoproteins uas muaj cov kua qaub oligosaccharides thiab sialic acids;
- ntau yam soluble Cheebtsam (proteins, proteoglycans, thiab lwm yam);
- molecules adsorbed rau ntawm daim nyias nyias los ntawm qhov chaw extracellular.
Cov qauv thiab cov ntsiab lus tseeb ntawm cov khoom siv biochemical ntawm glycocalyx sib txawv nyob ntawm seb hom ntawm tes, nrog rau lub cev thiab cov khoom siv ib puag ncig.
Kev siv cov dyes tshwj xeeb ua kom pom lub plhaub ntxiv no siv hluav taws xob microscopy.
YEndothelial Hycocalyx
Endothelial glycocalyx yog txheej nplua nuj nyob rau hauv carbohydrates uas kab cov luminal nto ntawm cov hlab ntsha thiab tsim ib tug tuab tuab (txog 500 nanometers) acellular membrane uas ua hauj lwm tsis tau tsuas yog nyob rau hauv lub cytological, tab sis kuj nyob rau hauv cov ntaub so ntswg theem. Cov qauv no tau pom thawj zaug los ntawm Luft 40 xyoo dhau los.
Tam sim no tau tsim tsa tias endothelial glycocalyx yog qhov tseem ceeb ntawm kev txiav txim siab ntawm vascular permeability. Hais txog cov ntshav khiav, nws muaj ib feem tsis zoo nqi, uas tiv thaiv kev nqus ntawm cellular albumin ntau. Lub glycocalyx kuj ua haujlwm raws li kev tiv thaiv txhua yam rau endothelium.
