hom amide daim ntawv cog lus uas tshwm sim thaum lub sij hawm tsim peptide proteins tom qab kev sib cuam tshuam ntawm ob amino acids, qhov no yog cov lus teb rau lo lus nug ntawm seb peptide daim ntawv cog lus yog dab tsi.
Los ntawm ib khub ntawm cov amino acids, ib dipeptide tshwm, uas yog, cov saw ntawm cov amino acids, ntxiv rau cov dej molecule. Raws li tib lub cev, cov saw ntev ntev yog tsim los ntawm cov amino acids hauv ribosomes, uas yog, polypeptides thiab cov proteins.
Chain Properties
Ntau yam amino acids, uas yog ib hom "cov khoom tsim" rau cov protein, muaj radical R.
Raws li nrog rau txhua yam amides, peptide daim ntawv cog lus ntawm C-N saw protein, los ntawm kev sib cuam tshuam ntawm cov qauv canonical ntawm carbonyl carbon thiab nitrogen atom, feem ntau muaj ob lub cuab yeej. Qhov no feem ntau pom kev qhia hauv kev txo nws qhov ntev mus rau 1.33 angstroms.
Txhua yam no ua rau cov lus xaus hauv qab no:
- C, H, O thiab N - 4 txuas atoms, ntxiv rau 2 a-carbons nyob rau tib lub dav hlau. R pab pawg ntawm cov amino acids thiaba-carbon hydrogens twb nyob sab nraum cheeb tsam no.
- H thiab O hauv peptide daim ntawv cog lus ntawm cov amino acids thiab cov a-carbons ntawm cov amino acid khub yog trans-oriented, txawm hais tias cov trans-isomer ruaj khov dua. Nyob rau hauv L-amino acids, cov R-groups kuj trans-oriented, uas muaj nyob rau hauv tag nrho cov peptides thiab proteins nyob rau hauv cov xwm.
- Kev tig ib ncig ntawm C-N saw yog qhov nyuaj, kev sib hloov ntawm C-C txuas yog qhov zoo dua.
Yuav kom nkag siab tias daim ntawv cog lus peptide yog dab tsi, nrog rau txhawm rau txheeb xyuas peptides lawv tus kheej nrog cov proteins thiab txiav txim siab lawv cov nyiaj hauv ib qho kev daws teeb meem, siv cov tshuaj tiv thaiv biuret.
Kev npaj ntawm atoms
Kev sib txuas hauv cov protein peptides luv dua li lwm pab pawg peptide, vim nws muaj cov yam ntxwv ntawm ob daim ntawv cog lus. Xav txog seb daim ntawv cog lus peptide yog dab tsi, peb tuaj yeem xaus tias nws qhov kev txav mus los tsawg.
Kev tsim hluav taws xob ntawm peptide daim ntawv cog lus teeb tsa cov qauv tsim qauv ntawm ib pawg peptides. Cov dav hlau ntawm cov pab pawg no nyob ntawm ib lub kaum sab xis rau ib leeg. Kev sib cog lus ntawm a-carbon atom thiab a-carboxyl thiab a-amino pawg tuaj yeem tig tau ywj pheej raws nws cov axis, thaum raug txwv hauv qhov loj thiab qhov xwm txheej ntawm cov radicals, thiab qhov no ua rau nws ua tau rau cov saw hlau polypeptide los teeb tsa nws tus kheej ntau yam. settings.
Peptide bonds hauv cov protein, raws li txoj cai, yog nyob rau hauv kev hloov pauv, uas yog, kev npaj ntawm a-carbon atoms nyob rau hauv ntau qhov chaw ntawm pab pawg. Qhov tshwm sim yog qhov chaw ntawm sab radicals nyob rau hauv cov amino acids ntawm qhov deb ntau nyob rau hauv qhov chaw ntawm ib leeg.phooj ywg.
YProtein rupture
Thaum kawm seb daim ntawv cog lus peptide yog dab tsi, nws lub zog feem ntau suav nrog. Xws li chains tsis tawg ntawm lawv tus kheej raws li ib txwm muaj nyob rau hauv lub cell. Ntawd yog, ntawm qhov tsim nyog lub cev kub thiab qhov chaw nruab nrab.
Hauv kev kuaj mob, cov hydrolysis ntawm cov protein peptide chains tau kawm nyob rau hauv kaw ampoules, nyob rau hauv uas muaj concentrated hydrochloric acid, ntawm ib tug kub ntawm ib puas thiab tsib degrees Celsius. Ua tiav cov protein hydrolysis kom dawb amino acids tshwm sim hauv 24 teev.
Ntawm lo lus nug ntawm dab tsi peptide daim ntawv cog lus nyob rau hauv cov kab mob nyob, ces lawv tawg tshwm sim nrog kev koom tes ntawm qee cov enzymes proteolytic. Txhawm rau nrhiav peptides thiab cov proteins hauv kev daws teeb meem, nrog rau txhawm rau txheeb xyuas lawv cov nyiaj, lawv siv cov txiaj ntsig zoo ntawm cov tshuaj uas muaj ob lossis ntau dua peptide bonds, uas yog, cov tshuaj tiv thaiv biuret.
Amino acid hloov
Inside qhov txawv txav hemoglobin S, 2 β-chains tau hloov pauv, uas glutamate, nrog rau qhov tsis zoo ntawm cov amino acid nyob rau hauv txoj hauj lwm thib rau, tau hloov nrog radical-muaj hydrophobic valine.
Inside the mutated hemoglobin is a region that complementary to another region with the tib molecules that has the altered amino acid. Thaum kawg, cov hemoglobin molecules "kab ua ke" thiab tsim ntev fibrillar aggregates uas hloov cov ntshav liab thiab ua rau cov tsos ntawm mutated crescent-zoo li cov qe ntshav liab.
Inside oxyhemoglobin S, raws li qhov tshwm sim ntawm kev hloov pauv hauv cov protein, qhov chaw ntxiv tau npog. Tsis muaj kev nkag mus rau nws ua rau nws tsis yooj yim rau cov molecules txuas mus rau ib leeg hauv cov oxyhemoglobin no. Muaj cov xwm txheej zoo rau kev tsim cov HbS aggregates. Lawv nce tsub zuj zuj ntawm deoxyhemoglobin hauv cov hlwb. Cov no yuav suav nrog:
- hypoxia;
- alpine mob;
- lub cev ua haujlwm;
- dav hlau ya.
Sickle Cell Anemia
Vim cov kab mob zoo li erythrocytes muaj qhov permeability tsawg los ntawm cov ntaub so ntswg capillaries, lawv tuaj yeem thaiv cov hlab ntsha thiab yog li tsim cov hypoxia hauv zos. Qhov no yuav ua rau kom cov deoxyhemoglobin S nyob rau hauv cov qe ntshav liab, nrog rau tus nqi ntawm S-hemoglobin aggregates tshwm sim thiab tsim ntau yam mob rau cov ntshav liab deformation.
Tus kab mob Sickle cell yog homozygous recessive kab mob uas tshwm sim tsuas yog thaum ob leeg niam txiv dhau ntawm ib khub ntawm cov noob caj noob ces hloov pauv. Tom qab tus me nyuam yug los, tus kab mob tsis tshwm sim nws tus kheej kom txog thaum lub HbF loj loj hloov mus rau HbS. Cov neeg mob qhia cov tsos mob uas yog yam ntxwv ntawm anemia, uas yog: mob taub hau thiab kiv taub hau, palpitations, ua tsis taus pa luv, tsis muaj zog rau cov kab mob, thiab hais txog.
