Qhov sib txawv tseem ceeb ntawm kev sib tham thiab cov qauv sib txuas ntawm allosterism yog nyob rau hauv kev sib koom ua ke, cov enzyme subunits tau txuas nrog txoj hauv kev uas hloov pauv hauv ib lub subunit yuav tsum tau xa mus rau tag nrho lwm cov subunits, whereas nyob rau hauv cov qauv ua ntu zus, subunits. tsis txuas nrog txoj hauv kev uas qhov kev hloov pauv hauv ib lub subunit ua rau muaj kev hloov pauv zoo sib xws hauv lwm tus.
Cov qauv sib tham thiab cov qauv sib txuas ntawm allosterism tuaj yeem piav qhia raws li ob tus qauv tseem ceeb ntawm tus cwj pwm ntawm allosteric enzymes. Cov qauv no tau qhia hauv xyoo 1965 thiab 1966, feem. Tam sim no, peb siv ob qho qauv no ua lub hauv paus rau kev txhais cov txiaj ntsig kev sim. Cov qauv kev sib tham muaj qhov zoo ntawm kev sib piv yooj yim thiab piav qhia txog tus cwj pwm ntawm qee lub tshuab enzyme zoo heev. Cov qauv ua ntu zus, ntawm qhov tod tes, qhia txog qee qhov yooj yim, tab sis tsuas yog rau qee cov duab tiag tiag ntawm cov qauv thiab tus cwj pwm ntawm cov protein. Hom no kuj cuam tshuam nrog tus cwj pwm ntawm qee lub tshuab enzyme zoo heev.
Tus Qauv Kev Sib Tham ntawm Allosterism yog dab tsi?
Tus qauv kev sib tham ntawm allosterism postulates tias enzyme subunits tau txuas nrog txoj hauv kev uas hloov pauv hauv ib lub subunit yuav tsum tau xa mus rau tag nrho lwm cov subunits. Qhov no tseem hu ua symmetry qauv lossis MWC qauv. Raws li tus qauv no, tag nrho cov subunits yuav tsum muaj nyob rau hauv tib lub conformation.
Daim duab 01: Allosteric Regulation (A – Active Site B – Allosteric Site C – Substrate D – Inhibitor E – Enzyme)
Tus qauv no tau qhia los ntawm Jacques Monod, Jeffries Wyman, thiab Jean-Pierre hauv xyoo 1965. Raws li tus qauv no, cov protein muaj ob qhov kev sib haum xeeb: active conformation R thiab inactive conformation T. R conformation khi lub substrate tightly, whereas., nyob rau hauv T conformation, lub substrate yog bonded tsawg nruj.
Ib qhov txawv ntawm cov qauv kev sib tham yog tias qhov kev hloov pauv ntawm txhua qhov subunits hloov ib txhij. Piv txwv li, nyob rau hauv ib tug hypothetical protein muaj ob subunits, ob lub subunits yuav hloov lub conformation ntawm lub inactive T conformation rau lub active R conformation.
Tus Qauv Ua Ntej ntawm Allosterism yog dab tsi?
Tus qauv ua ntu zus ntawm allosterism tuaj yeem piav qhia raws li tus qauv ncaj qha ntawm tus cwj pwm allosteric. Cov qauv no muaj qhov sib txawv ntawm kev khi lub substrate uas ua rau muaj kev hloov pauv ntawm daim ntawv T mus rau R daim ntawv. Qhov no ua rau muaj kev sib koom tes sib koom ua ke ntawm cov qauv no.
Daim duab 02: Tus Qauv Ua Ntej
Ntxiv mus, nyob rau hauv cov qauv no, tag nrho cov activators thiab inhibitors yog khi los ntawm induced-fit mechanism. Ntawm no, kev hloov pauv hauv cov inhibitor lossis activator nyob rau hauv ib qho ntawm cov subunits cuam tshuam rau cov conformations ntawm lwm subunits.
Cov yam ntxwv tseem ceeb tshaj plaws ntawm cov qauv ua ntu zus suav nrog: nws cov subunits tsis tas yuav muaj nyob rau hauv tib lub conformation, nws cov kev hloov pauv tsis tau pom zoo rau txhua lub subunits, thiab cov molecules ntawm substrates khi los ntawm induced-fit raws tu qauv.
Dab tsi yog qhov txawv ntawm Concerted thiab Sequential Model of Allosterism?
Qhov sib txawv tseem ceeb ntawm kev sib tham thiab cov qauv sib txuas ntawm allosterism yog tias nyob rau hauv kev sib koom ua ke, kev hloov pauv hauv ib lub subunit yuav tsum tau xa mus rau tag nrho lwm cov subunits, whereas nyob rau hauv cov qauv ua ntu zus, kev hloov pauv hauv ib lub subunit tsis yog. txhawb kom muaj kev hloov pauv zoo sib xws hauv lwm tus.
Summary – Concerted vs Sequential Model of Allosterism
Tus qauv sib tham ntawm allosterism yog tus qauv uas qhia tias cov enzyme subunits tau txuas nrog txoj hauv kev uas hloov pauv hauv ib lub subunit yuav tsum tau xa mus rau tag nrho lwm cov subunits. Tus qauv ua ntu zus ntawm allosterism yog tus qauv ncaj qha ntawm tus cwj pwm allosteric. Hauv cov qauv no, kev hloov pauv hauv ib lub subunit tsis ua rau muaj kev hloov pauv zoo sib xws hauv lwm qhov. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev sib tham thiab cov qauv sib txuas ntawm allosterism.
