M'dziko lochititsa chidwi la microbiology, peptidoglycan, yomwe imadziwikanso kuti murein, imaonekera ngati yomangamanga. ya khoma selo ya bakiteriya. Chosanjikiza cholimbachi, chomwe chili pansi pa nembanemba ya plasma, chimapatsa mabakiteriya mawonekedwe awo ndipo amagwira ntchito yofunika kwambiri poteteza ndi kukana kusiyanasiyana kwa chilengedwe komanso tizilombo toyambitsa matenda. Koma ndichifukwa chiyani dongosololi limatchedwa peptidoglycan? M'nkhaniyi, tiwona maziko a dzinali ndikufufuza momwe zimakhalira ndi ntchito zofunika peptidoglycan mu mabakiteriya.
I. Mau oyamba a peptidoglycan ngati wosanjikiza wa khoma la bakiteriya cell
Peptidoglycan ndi molekyulu yofunikira yomwe imapezeka m'thupi khoma la selo wa mabakiteriya. Ndiwosanjikiza wokhazikika womwe umapereka chithandizo ndi chitetezo ku maselo a bakiteriya, kutsimikizira kukhulupirika kwawo. Molekyuyi imapangidwa ndi netiweki yamitundu itatu yopangidwa ndi maunyolo osinthika a N-acetylglucosamine ndi N-acetylmuramic acid, olumikizidwa ndi ma peptide.
Kuwonjezera pa kupereka rigidity kuti khoma la cell mabakiteriya, peptidoglycan amathandizanso kwambiri pakusunga mabakiteriya mawonekedwe a selo ndi kukana kupanikizika kwa osmotic. Chifukwa cha kuuma kwake komanso kusamva bwino, peptidoglycan imalola mabakiteriya kukhalabe ndi mawonekedwe awo ndipo amatha kupirira kusintha kwa kuthamanga kwa osmotic. Popanda wosanjikiza wouma woterewu, mabakiteriya amatha kuwonongeka komanso kusungunuka kwa maselo.
Mapangidwe a peptidoglycan ali ndi zinthu zingapo zofunika. Kumbali imodzi, chimango chake cha mbali zitatu chimapangidwa makamaka ndi maunyolo ozungulira a N-acetylmuramic acid ndi mayunitsi a N-acetylglucosamine. Maunyolo awa amawoloka wina ndi mzake ndi milatho ya peptide, yomwe imapereka kukhazikika kwakukulu kwa kapangidwe kake ka peptidoglycan. Kuphatikiza apo, mu mabakiteriya ena, mamolekyu owonjezera amatha kupezeka, monga ma teichoic acid ndi lipoteichoic acid, omwe amamangiriza ku peptidoglycan ndikuthandizira kugwira ntchito kwake.
II. Chemical zikuchokera peptidoglycan ndi structural ntchito
Peptidoglycan ndi gawo lofunikira wa cell wall mabakiteriya ndi archaea, kupereka kukhazikika ndi chitetezo ku maselowa. Mapangidwe ake amapangidwa makamaka ndi maunyolo amtundu wa polysaccharide opangidwa ndi kubwereza kwa mitundu iwiri ya mayunitsi a shuga, N-acetylglucosamine (NAG) ndi N-acetylmuramic acid (NAM). Maunyolo amenewa amalumikizana kupanga mauna atatu-dimensional omwe amazungulira selo ndikupereka mawonekedwe ake.
Mapangidwe a peptidoglycan amaphatikizanso maunyolo afupiafupi a peptides olumikizidwa ndi N-acetylmuramic acid. Mapangidwe a ma peptidewa amatha kusiyanasiyana pakati pa mitundu yosiyanasiyana ya mabakiteriya ndi ma archaeal, kupereka kusinthasintha kwa mawonekedwe a khoma la cell. Kugwirizana pakati pa ma peptides ndi shuga kumapereka kukana kwambiri kupsinjika, kuwonetsetsa kuti maselo amakhazikika.
Ntchito yayikulu ya peptidoglycan ndikupereka chithandizo ndi kukana kupsinjika kwa osmotic. Kuphatikiza pakusunga mawonekedwe a cell, kapangidwe ka peptidoglycan kamalola kukana kusintha kwadzidzidzi kwamphamvu. Makhalidwewa ndi ofunika kwambiri kwa mabakiteriya ndi archaea omwe amakhala m'madera ovuta kwambiri omwe thupi likhoza kukhala losiyana kwambiri. Kukhazikika kwa peptidoglycan kumaperekanso chotchinga chogwira ntchito motsutsana ndi kulowa kwa mamolekyu ndi tizilombo toyambitsa matenda, motero kuteteza cell ya bakiteriya kapena zakale kuti zisawonongeke.
III. Peptidoglycan monga gawo lofunikira pachitetezo cha bakiteriya komanso kukhazikika
Peptidoglycan ndi gawo lofunikira pakutetezedwa komanso kukhazikika kwa bakiteriya. Ndilo dongosolo lolimba lomwe lili mu cell khoma la mabakiteriya, lomwe limapereka kukana kwamakina ndi chitetezo ku osmotic lysis. M'munsimu muli mfundo zitatu zofunika kwambiri za peptidoglycan pa kupulumuka kwa mabakiteriya:
1. Chitetezo ku zigawenga zakunja: Peptidoglycan ndi chotchinga champhamvu chomwe chimateteza mabakiteriya kuzinthu zosiyanasiyana zakunja, monga zochita za michere ya lytic komanso kukhudzana ndi mankhwala opha tizilombo. Kapangidwe kameneka kamapereka chishango kwa mabakiteriya, kuwalepheretsa kusweka ndikuwasunga bwino pakachitika zovuta zachilengedwe.
2. Kusamalira mawonekedwe a cell: Peptidoglycan imathandizira kuti mabakiteriya akhale olimba komanso osasunthika, chifukwa amagwira ntchito ngati scaffold yomwe imathandizira cell. Chifukwa cha izi, mabakiteriya amatha kusunga mawonekedwe awo, kutsimikizira magwiridwe antchito awo ndikupewa zopindika zomwe zingakhudze kagayidwe kawo komanso kuthekera kwawo kuberekana.
3. Kukana kukakamizidwa kwa osmotic: Peptidoglycan ndiyofunikira makamaka pakusunga umphumphu wa khoma la cell ya bakiteriya poyang'anizana ndi kusintha kwa chilengedwe cha osmotic pressure. Kapangidwe kameneka kamapangitsa mabakiteriya kukhala okhoza kupirira kusiyana kwa ndende ya solute pakati pa kunja ndi mkati mwa selo, kuteteza kulowa kwa madzi mopitirira muyeso ndikusunga cell turgor yofunikira kuti ipulumuke.
IV. Peptide ndi glycosidic zomangira mu peptidoglycan ndi kufunika kwawo
Peptidoglycan ndi gawo lofunikira pama cell a bakiteriya, omwe amapereka kukhazikika komanso chitetezo. Polima uyu amapangidwa kuchokera ku mgwirizano wa mitundu iwiri ya zomangira: zomangira za peptide ndi zomangira za glycosidic.
Zomangira za peptide zimakhazikitsidwa pakati pa ma amino acid omwe amapanga peptidoglycan, zomwe zimapangitsa kuti pakhale mawonekedwe amitundu itatu. Zomangirazi zimalimbana kwambiri ndipo zimathandizira kukana kwamakina kwa khoma la cell ya bakiteriya, kuteteza kuphulika pansi pa zovuta za osmotic.
Kumbali ina, zomangira za glycosidic zimapangidwa pakati pa shuga N-acetylglucosamine (NAG) ndi N-acetylmuramic acid (NAM) yomwe imapanga peptidoglycan. Zomangira izi ndizofunikira kuti chitetezo cha cell chisungike ndikuwonetsetsa ntchito yake yoteteza. Kuphatikiza apo, zomangira za glycosidic zimalola kukulitsa kwa peptidoglycan, kulola kukula kwa maselo ndi kugawikana.
V. Peptidoglycan monga chithandizo chamankhwala pakupanga maantibayotiki atsopano
Peptidoglycan ndi wosanjikiza wokhazikika womwe umapezeka m'maselo a mabakiteriya ndipo umagwira ntchito yofunika kwambiri kuti apulumuke. Ndilo chandamale chachikulu cha mankhwala a beta-lactam, monga penicillin ndi amoxicillin. Komabe, m'zaka makumi angapo zapitazi, pakhala kuwonjezeka koopsa kwa kukana kwa maantibayotikiwa, zomwe zimapangitsa kuti pakhale kufunikira kopanga mankhwala atsopano omwe amayang'ana peptidoglycan.
Asayansi akhala akufufuza njira zosiyanasiyana zoletsa kaphatikizidwe ka peptidoglycan kapena kuwonongeka ngati njira yothanirana ndi mabakiteriya osamva. Imodzi mwa njira zodalirika kwambiri ndikukula kwa zoletsa za enzyme transpeptidase, zomwe zimatenga nawo gawo pakupanga maulalo ofunikira mu peptidoglycan. Zoletsa izi zingathandize kufooketsa khoma la cell ya bakiteriya ndikupangitsa kuti mabakiteriya azitha kugwidwa ndi maantibayotiki ena.
Kuphatikiza pa transpeptidase enzyme inhibitors, njira zina zowunikira peptidoglycan zikufufuzidwa. Izi zikuphatikizapo kufufuza kwa mankhwala omwe amasokoneza kaphatikizidwe ka peptidoglycan precursors, komanso othandizira omwe amagwira ntchito pa ma enzyme omwe amawononga dongosololi. Njira zosiyanasiyanazi zimafuna kufooketsa khoma la cell ya bakiteriya ndikuwonjezera mphamvu ya maantibayotiki omwe alipo kapena kupanga maantibayotiki atsopano omwe ali odziwika kwambiri a peptidoglycan.
SAW. Zinthu zomwe zimakhudza kaphatikizidwe ka peptidoglycan ndi ubale wake ndi kukana kwa bakiteriya
Peptidoglycan ndi gawo lofunikira pama cell khoma la mabakiteriya ndipo limagwira ntchito yofunika kwambiri pakukana kwawo. Peptidoglycan synthesis imayendetsedwa ndi zinthu zingapo zomwe zingakhudze kukana kwa bakiteriya. Apa tikambirana zina mwazinthu izi ndi ubale wawo ndi kaphatikizidwe ka peptidoglycan komanso kukana kwa bakiteriya.
1. Ma enzymes omwe amaphatikizidwa mu kaphatikizidwe ka peptidoglycan: Kaphatikizidwe ka peptidoglycan kumaphatikizapo ma enzyme angapo omwe amathandizira magawo osiyanasiyana a njirayi. Ma enzymes awa akuphatikizapo ligases, synthetases, ndi hydrolases, omwe amachititsa kupanga ndi kusinthidwa kwa peptide ndi glycosidic bond mu peptidoglycan. Kusintha kulikonse m'ntchito ya michereyi kumatha kukhudza kaphatikizidwe ka peptidoglycan, motero, kukana kwa bakiteriya.
2. Kukhalapo kwa maantibayotiki: Maantibayotiki ena amachitapo kanthu poletsa kaphatikizidwe ka peptidoglycan. Mwachitsanzo, penicillin ndi vancomycin amachita poletsa ntchito ya michere yomwe imayambitsa mapangidwe a peptide mu peptidoglycan. Kukhalapo kwa maantibayotikiwa kumatha kuchedwetsa kapena kuyimitsa kaphatikizidwe ka peptidoglycan, zomwe zimapangitsa kuti mabakiteriya achepetse.
3. Zinthu zokhudza majini: Kaphatikizidwe ka peptidoglycan kumatsimikiziridwa ndi gawo limodzi ndi chidziwitso cha chibadwa cha mabakiteriya. Kusintha kwa majini ophatikizira ma enzymes omwe amaphatikizidwa mu kaphatikizidwe ka peptidoglycan kumatha kusokoneza ntchito yawo, chifukwa chake, kukana kwa bakiteriya. Kuphatikiza apo, kupezeka kwa majini olimbana ndi mabakiteriya, monga ma encoding efflux mapampu ndi ma enzymes osintha, kumathanso kukhudza kaphatikizidwe ka peptidoglycan komanso kukana kwa bakiteriya.
VII. Peptidoglycan ngati chizindikiro cha taxonomic ndikuthandizira kwake pakuzindikiritsa mabakiteriya
Peptidoglycan ndi gawo lofunikira pama cell khoma la mabakiteriya, ndipo kapangidwe kake kapadera kamapangitsa kukhala chizindikiro chofunikira kwambiri pakuzindikiritsa mabakiteriya. Kapangidwe ndi kagawidwe ka ma peptide bond ndi mamolekyu a glucose omwe amapezeka mu peptidoglycan amasiyana pakati pa mitundu yosiyanasiyana ya mabakiteriya, zomwe zimawalola kuti azisiyanitsidwa ndikugawidwa m'magulu osiyanasiyana.
Kudziwitsa za peptidoglycan mu chitsanzo cha bakiteriya kumatha kuchitidwa pogwiritsa ntchito njira zosiyanasiyana, monga ma infrared spectroscopy, chromatography, ndi ma electron microscopy. Njirazi zimalola kuti peptidoglycan iwunikidwe komanso kapangidwe kake, komwe ndi kofunikira pakuzindikiritsa bwino mabakiteriya.
Kuthandizira kwa peptidoglycan pakuzindikiritsa mabakiteriya ndikofunika kwambiri chifukwa cha kukhazikika kwake komanso kusungidwa kwachisinthiko. Chigawochi chimapezeka m'mabakiteriya ambiri, ndikupangitsa kukhala chizindikiro chodalirika komanso chogwiritsidwa ntchito kwambiri mu maphunziro a taxonomic ndi phylogenetic. Kuthekera kwake kusiyanitsa mitundu ya mabakiteriya, ngakhale pamikhalidwe yofanana kwambiri ya majini, kumapangitsa kukhala chida chofunikira kwambiri pakugawa molondola mabakiteriya.
Mafunso ndi Mayankho
Q: Chifukwa chiyani wosanjikiza wa khoma la bakiteriya cell amatchedwa Peptidoglycan?
A: Dzina lakuti Peptidoglycan limagwiritsidwa ntchito kutanthauza kusanjikiza kolimba komwe kuli mu cell khoma la bakiteriya chifukwa cha kapangidwe kake ndi mawonekedwe ake.
Q: Kodi Peptidoglycan imapangidwa bwanji?
A: Peptidoglycan imapangidwa ndi maunyolo aatali, olumikizana obwerezabwereza a mayunitsi a N-acetylglucosamine (NAG) ndi N-acetylmuramic acid (NAM). Mayunitsi awa amalumikizidwa ndi ma glycosidic bond.
Q: Kodi ntchito ya Peptidoglycan mu khoma la bakiteriya cell ndi chiyani?
A: Peptidoglycan ndiyofunikira kuti ipereke kukhazikika komanso chitetezo ku cell ya bakiteriya. Zimakhala ngati chotchinga chakuthupi chomwe chimalepheretsa cell lysis ndikuthandizira kusunga mawonekedwe a mabakiteriya.
Q: Kodi Peptidoglycan imathandizira bwanji kukana maantibayotiki?
Yankho: Peptidoglycan ndiye chandamale chachikulu cha maantibayotiki ambiri, chifukwa kaphatikizidwe ndi kapangidwe kake ndizofunikira kwambiri pochiza matenda a bakiteriya. Mabakiteriya omwe amayamba kukana maantibayotikiwa nthawi zambiri amakhala ndi masinthidwe kapena njira zosinthira Peptidoglycan zomwe zimawalola kukana zochita zawo.
Q: Kodi pali mabakiteriya omwe alibe Peptidoglycan mkati? cell khoma lake?
A: Inde, pali mabakiteriya omwe amadziwika kuti mycoplasmas omwe alibe Peptidoglycan m'makoma awo. Mabakiteriyawa apanga njira zina zosungira kukhulupirika kwa maselo awo, monga kuphatikizika kwa lipids owonjezera.
Q: Chifukwa chiyani ndikofunikira kuphunzira Peptidoglycan?
Yankho: Kafukufuku wa Peptidoglycan ndi wofunikira kwambiri pakumvetsetsa kapangidwe ka cell cell ya bakiteriya, komanso kupanga njira zatsopano zochizira matenda oyambitsidwa ndi mabakiteriya. Kuphatikiza apo, kumvetsetsa momwe mabakiteriya angasinthire kapena kupeŵa zochita za Peptidoglycan kumatithandiza kuthana ndi vuto lomwe likukulirakulira la kukana kwa maantibayotiki.
Njira Yopita Patsogolo
Mwachidule, mawu oti "peptidoglycan" amagwiritsidwa ntchito kutanthauza kusanjikiza kwa khoma la cell ya bakiteriya chifukwa chapadera komanso chofunikira kwambiri mu mabakiteriya. Mapangidwe a polymeric awa amapangidwa makamaka ndi maunyolo a shuga opangidwa ndi N-acetylglucosamine ndi mayunitsi a N-acetylmuramic acid olumikizidwa palimodzi. Maunyolowa amalumikizidwa ndi milatho ya peptide, yomwe imapereka bata komanso kukana khoma la cell ya bakiteriya.
Ntchito yayikulu ya peptidoglycan ndikupereka kukana kwa mabakiteriya ndikuwateteza ku osmotic lysis. Kuphatikiza apo, wosanjikiza wowumawu umagwiranso ntchito ngati nsanja yomangirira mapuloteni ndi ma enzymes omwe amagwira ntchito yofunika kwambiri pakugwira ntchito kwa bakiteriya komanso kukhala ndi moyo.
Kuphunzira ndi kumvetsetsa kwa peptidoglycan kwatilola kuti tifufuze njira zotsutsana ndi maantibayotiki, kupanga mankhwala atsopano oletsa tizilombo toyambitsa matenda komanso kufufuza njira zochepetsera khoma la bakiteriya komanso kuthana ndi matenda. Kupyolera mu kafukufuku wowonjezera, tikuyembekeza kupitiriza kukulitsa chidziwitso chathu cha gawo lofunikirali ndikupitiriza kuthandizira kupititsa patsogolo kwa microbiology ndi mankhwala.
Pomaliza, mawu akuti "peptidoglycan" amatanthauza kusanjika kwa khoma la cell ya bakiteriya chifukwa cha mawonekedwe ake apadera komanso gawo lofunikira pakupulumuka kwa mabakiteriya. Kafukufuku wawo akupitiriza kukhala wofunika kwambiri, chifukwa amathandizira kumvetsetsa kwathu kwa antimicrobial resistance ndipo amatilola kufufuza njira zatsopano zolimbana ndi matenda a tizilombo.
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