Cov theem ntawm cov yam ntxwv lub koom haum ntawm cov protein molecules los yog protein qauv

Tus qauv ntawm cov protein molecule raug kawm rau ntau tshaj 200 xyoo. Nws yog lub npe hu rau ntau proteins. Ib txhia ntawm lawv tau tsim (e.g., insulin, RNase). Cov yooj yim yam ntxwv thiab tej chav tsev uas muaj protein ntau molecules los ntawm cov amino acids. Tsis tas li ntawd lub carboxyl thiab amino pawg thiab proteins muaj lwm yam functional pawg, uas txiav txim lawv lub zog. Tej pab pawg muaj xws li muab tso rau hauv lub sab branchings protein molecule: carboxy pab pawg neeg ntawm aspartic acid los yog glutamic acid, amino pab pawg neeg ntawm lysine los yog hydroxylysine, guanidine pab pawg neeg ntawm arginine, lub imidazole pab pawg neeg ntawm histidine, lub hydroxyl pab pawg neeg ntawm serine thiab threonine, ib tug phenol pab pawg neeg ntawm tyrosine, lub sulfhydryl pab pawg neeg ntawm cysteine, disulfide pab pawg neeg ntawm cystine, thioether pab pawg neeg ntawm methionine, phenylalanine benzelnoe tub ntxhais, aliphatic chains ntawm lwm cov amino acids.

Muaj plaub theem ntawm cov yam ntxwv lub koom haum ntawm cov protein molecules.

Lub hom qauv ntawm cov protein. Amino acids nyob rau hauv lub protein molecule yog koom ua ke los ntawm peptide bonds, yog li txoj kev ua thawj qauv. Nws nyob ntawm tus zoo muaj pes tsawg leeg ntawm cov amino acids, lawv muaj pes tsawg thiab ib theem zuj zus ntawm lub tebchaw. Lub hom qauv ntawm cov protein feem ntau txiav txim los ntawm Sanger. Qhov kev kuaj ntawd protein yog kho nrog ib tug daws ditroftorbenzola (DNP), li no txoj kev dinitrophenyl-protein (protein-DNP). Tom qab DNP-hydrolyzed protein tsim residue protein molecule thiab DNP-amino acid. DNP-amino acid yog zoo los ntawm no sib tov thiab feem cuam hydrolysis. Cov khoom ntawm hydrolysis yog cov amino acid thiab dinitrobenzene. Cov seem ntawm cov protein molecule hnov mob nrog tus tshiab feem ntawm DNP li ntev raws li tag nrho cov molecule tsis tawg cia rau hauv amino acids. Raws li cov ntau txoj kev tshawb no ntawm amino acids ua li cov thawj cov qauv ntawm tus neeg Circuit Court protein. Paub thawj qauv ntawm cov nqaijrog insulin, myoglobin, hemoglobin, glucagon thiab ntau lwm tus neeg).

Los ntawm cov qauv ntawm cov Edman protein yog kho nrog phenyl isothiocyanate. Tej zaum siv proteolytic enzymes - trypsin, pepsin, chymotrypsin, peptidase, etc.

Cov theem nrab qauv ntawm cov protein. American zaum, siv X-ray tsom xam, pom hais tias cov protein polypeptide chains feem ntau muaj nyob rau hauv daim ntawv ntawm alpha-helices thiab tej zaum beta lug.

Alpha-helix yog muab piv nrog ib tug kauv staircase, uas ua cov kev ua ntawm cov degrees ntawm amino acid residues. Nyob rau hauv molecules fibrillar cov nqaijrog (txhob lo lo ntxhuav fibroin) polypeptide saw yog yuav luag tag ncav us txog (beta-qauv) thiab cov txheej txheem ntawm nyob rau hauv daim ntawv ntawm cov spheres, stabilized los ntawm hydrogen bonds.

Alpha-helix peev xwm yuav tsim nthawv nyob rau hauv cov khoom cua polypeptides (dederon, nylon), uas muaj ib tug molecular ceeb thawj los ntawm los ntawm 10 mus rau 20 txhiab. Yog. Nyob rau tej feem ntawm lub molecule cov nqaijrog (insulin, hemoglobin, RNAse) lov cov alpha helical configuration ntawm cov peptide saw, thiab raug tsim helical qauv ntawm lwm hom.

Lub tertiary qauv ntawm cov protein. Muab Kauv feem ntawm lub polypeptide saw ntawm cov protein molecule yog nyob rau hauv txawv kev sib raug zoo uas txiav txim tertiary (peb-dimensional) qauv, daim ntawv thiab kev zoo ntawm qhov ntim ntawm lub protein molecule. Nws yog ntseeg hais tias cov tertiary qauv ntawm cov tsis siv neeg thiab tshwm sim vim muaj ib tug sis raug zoo nrog cov amino acid seem ntawm lub kuab molecules. Yog li hydrophobic radicals "twv" mus rau hauv lub protein molecule, txoj kev ua lawv qhuav tsam thiab hydrophilic pawg neeg taw qhia kom paub mus rau lub hnyav, uas ua rau yus mus rau tsim ntawm energetically paaj pom molecule. Qhov no tus txheej txheem no nrog lub tsim ntawm intramolecular bonds. Lub tertiary qauv ntawm cov protein molecule transcribed rau RNAse, hemoglobin, lysozyme ntawm nqaij qaib qe.

Lub quaternary qauv ntawm cov protein. Qhov no hom ntawm cov qauv ntawm cov protein molecule tshwm sim raws li ib tug tshwm sim ntawm lub koom haum ntawm ob peb subunits kev mus rau hauv ib tug ib molecule. Txhua subunit muaj ib tug thawj, nrab thiab tertiary qauv.