Proline yog dab tsi: Nkag siab proline
Proline yog ib qho tseem ceeb amino acid nyob rau hauv tib neeg lub cev. Proline muaj peb hom: DL-proline, L-proline, thiab D-proline. Lub proline uas feem ntau yog hu ua L-proline, ib txwm tshwm sim amino acid uas yog ib qho siv lead ua columnar ntawm chav tsev kub. Nws sai sai decomposes ntawm 215-220 degree thaum rhuab. Nws yog soluble nyob rau hauv dej kub thiab ethanol, muaj ib tug me ntsis qab zib saj, thiab yog hygroscopic. Nws tig mus rau sab laug hauv cov tshuaj alkaline. [ ]D25-86.5 degree (dej), -60.4 degree (5N hydrochloric acid). Nws muaj nyob rau hauv ntau yam proteins. Nws yog ib qho tseem ceeb ntawm cov amino acid nyob rau hauv marine planktonic kab mob thiab tseem muaj nyob rau hauv seawater, hais, thiab marine sediments.
Proline yog dab tsi: Protein qauv zog
Lub cim cyclic qauv ntawm proline sab saw muab proline zoo heev conformational rigidity piv rau lwm cov amino acids. Nws kuj cuam tshuam rau tus nqi ntawm peptide daim ntawv cog lus ntawm proline thiab lwm yam amino acids. Thaum proline raug khi rau cov pab pawg amide hauv peptide daim ntawv cog lus, nws cov nitrogen tsis khi rau ib qho hydrogen, uas txhais tau hais tias nws tsis tuaj yeem pub hydrogen bonds tab sis tuaj yeem txais cov ntawv cog lus hydrogen.
Kev tsim ntawm peptide daim ntawv cog lus nrog cov khoom Pro-tRNAPro yog qeeb qeeb dua nrog lwm yam tRNA, uas yog ib qho tseem ceeb ntawm N-alkyl amino acids. Kev tsim ntawm peptide daim ntawv cog lus ntawm cov khoom tRNA thiab cov saw xaus hauv proline kuj qeeb. Kev tsim ntawm cov nyiaj proline-proline yog qhov qeeb tshaj plaws.
Qhov tshwj xeeb conformational rigidity ntawm proline cuam tshuam rau cov qauv thib ob ntawm cov proteins nyob ze ntawm cov residues proline thiab yuav piav qhia txog qhov ntau dua ntawm proline hauv cov kab mob thermophilic. Cov qauv protein thib ob tuaj yeem piav qhia los ntawm dihedral cov ces kaum φ, ψ, thiab ω ntawm cov pob txha protein. Cov qauv cyclic ntawm proline sab saw xauv lub kaum sab xis φ ntawm li -65 degree .
Proline tuaj yeem ua raws li kev cuam tshuam ntawm cov qauv hauv cov qauv txheej txheem thib ob xws li -helices thiab -sheets; Txawm li cas los xij, proline kuj feem ntau pom zoo li xth residue hauv ib qho -helix thiab ntawm cov npoo ntawm -cov ntawv. Proline lactobacillus hmoov kuj muaj nyob rau hauv lem (lwm tus qauv theem nrab), pab tsim - tig. Qhov no yuav piav qhia qhov txawv qhov tseeb tias proline feem ntau raug rau cov kuab tshuaj txawm tias muaj cov saw hlau tsis muaj polar kiag li.
Sib law liag prolines los yog hydroxyprolines tuaj yeem tsim polyproline helices, uas yog cov qauv thib ob hauv collagen. Hydroxylation ntawm proline nce qhov kev ruaj ntseg ntawm collagen los ntawm prolyl hydroxylase. Yog li ntawd, proline hydroxylation yog ib qho tseem ceeb ntawm biochemical txheej txheem los tswj cov kab mob siab dua 'cov ntaub so ntswg sib txuas. Cov kab mob hnyav xws li scurvy tuaj yeem tshwm sim los ntawm qhov tsis xws luag hauv qhov hydroxylation, xws li kev hloov pauv ntawm prolyl hydroxylase lossis tsis muaj ascorbic acid (vitamin C) cofactors.