Chimie biologica

MII)(50AMINOACIZI de ulemacromolec

Fe Mg, Cu,S P,

N

O

H

C

cuaternare Subst.

STRUCTURA

CHIMICA COMPOZITIECataliz enzimatic.Transport i stocare.Micare coordonat.Suport mecanic.Imunitate.

EINEHETEROPROT

NEHOLOPROTEIPROTEINE

EPOLIPEPTID

DEOLIGOPEPTIPEPTIDE

PROTIDE

R

NH

COOH

2

CH

alaninaβexceptie

α

proteine20

aa 200

1) Clasificarea aminoacizilor din punct de vedere structural

a) Aminoacizi cu caten hidrocarbonat - Glicina (Gly)- Alanina (Ala)- Valina (Val)- Leucina (Leu)- Izoleucina (Ile)

A) AMINOACIZI ALIFATICI

1) Clasificarea aminoacizilor din punct de vedere structural1) Clasificarea aminoacizilor din punct de vedere structural

b) Aminoacizi hidroxilai

- Serina (Ser)

- Treonina (Thr)

c) Aminoacizi sulfurai

- Cisteina (Cys)

- Cistina (Cyss)

- Metionina (Met)

d) Aminoacizi dicarboxilici

- Acidul aspartic (Asp) i asparagina (Asn)

- Acidul glutamic (Glu) i glutamina (Gln)

e) Aminoacizi bazici

- Lizina (Lys)

- Arginina (Arg)

- Histidina (His)

B) AMINOACIZI CICLICI

a) Aminoacizi aromatici

- Fenilalanina (Phe)

- Tirozina (Tyr)

- Triptofan (Trp)b) Aminoacizi heterociclici

- Prolina (Pro) - Hidroxiprolina (HO-Pro)

2) Clasificarea aminoacizilor in functie de rolul biologic

a)Aminoacizi eseniali (Thr, Met, Leu, Ile, Val, Lys, Phe, Trp)

b) Aminoacizi parial eseniali (His, Arg)

c) Aminoacizi neeseniali (restul)

H COOH

NH2

CH

glicina

(acid - aminoacetic)

CH2

CH3

COOH

NH

monometil-glicina(sarcozina)

CH2COOH

N

H3C CH3 CH3

+

trimetil-glicina(betaina)

-structura gelatinei i fibroinei (25%, 40%); -compoziia acizilor biliari, glutationului,-particip la sinteza de purine i de porfirine;-participa la eliminarea nucleului benzenic sub forma de acid hipuric

ROL

(C6H5-CO-NH-CH2-COOH

Surse de grupari –CH3

H3C CH

NH2

COOH

a - alanina

(acidul -amino-propionic)

CH2

NH2

COOHCH2

- alanina

ROL

anserina

carnozinamusculare dipeptide

A coenzima

pantotenic acid

compozitia in intra

neproteic aa

CH3 CH CH COOH

CH3 NH2

valina

(acidul -amino-izovalerianic)

(aa esenial)

CH3 CH

CH3

CH2 CH COOH

NH2

leucina

(acidul -amino-izocaproic)

(aa esenial)

CH3 CH2 CH CH COOH

CH3 NH2

izoleucina

(acidul -amino--metil valerianic)

(aa esenial)

COOHCH

NH2

serina

CH2

OH

COOHCHCH2

NH2O

P O

OH

OH

fosfoserina

(acidul -amino--hidroxi-propionic)

COOHCH

NH2

CH

OH

CH3

treonina

(acidul -amino--hidroxi-butiric)

(aa esenial)

CH2 CH COOH

NH2SH

cisteina

(acidul -amino--mercapto-propionic)

CH2 CH COOH

NH2SH

cisteina

2CH2 CH COOH

NH2S

S

CH2 CH COOH

NH2

cistina

+ 2H+ + 2e-

)(CoenzimaA CISTEAMINAareDecarboxil

.biliariac TAURINAcistic ac.avansata Oxidare2CO

HS - CH2 - CH2 - NH2

Cisteamina

CH2

S

CH2 CH COOH

NH2

CH3metionina

(aa esenial)

surs de metil

(acidul -amino--metil-mercaptobutiric)

CH COOH

NH2

HOOC CH2

acid aspartic

CH COOH

NH2

CH2CO

NH2

asparagina

(acidul -amino succinic)

CH COOH

NH2

HOOC CH2 CH2

acid glutamic

(acidul -amino-glutaric)

animaleGLUTAMINA

vegetaleASPARAGINAAMINIC AZOT

aDepozitare

reaTransporta

ROL

CH COOH

NH2

OC CH2 CH2

NH2

glutamina

CH COOH

NH2

CH2 CH2CH

2NH2

lizina

abgdeCH2

(acidul ,-diamino-caproic)

CH COOH

NH2

CH CH2CH2

NH2OH

4-hidroxi-lizina

CH2

COLAGEN

GELATINAlizinaHidroxi

esential Aa.

ROL

COMPOZITIA

CH COOH

NH2

CH2 CH2CH2NHNH2

NH

Cabgd

arginina

(acidul -amino--guadin-valerianic)

PROTAMINE

HISTONEBAZICE proteine Compozitia

CUREOGENETICICLUL

esential .partial Aa

ROL

CH COOH

NH2NHN

a

histidina

CH2

b

(acidul -amino--imidazol-propionic)

(imidazol-alanina)

GLOBULINE Compozitie

ANIMALE

COPIIesential Aa.

ROL

CH COOH

NH2

aCH2

b

fenilalanina (acidul -amino--fenil-propionic)

(aa esenial)

CH COOH

NH2

aCH2

bOH

tirozina

(acidul -amino--(para-hidroxi-fenil)-propionic)

NH

CH COOH

NH2

aCH2

b

triptofan

(acidul -amino--indol-propionic) (indol-alanin)

(aa esenial)

melaninici pigmenti

inanorepinefr

epinefrina

dopamina

necatecolami

(tiroxina) tiroidieni hormoni

precursoriPhe

Tyr

zAdamkiewic

Millon

icaxantoprote

reactii apozitiveaz

280 λLUV absorbtie max.

Trp

Tyr

ROL

(acidul pirolidin-2-carboxilic)

NH

COOH

prolina

glicina) (dupa Nstr.COLAGE in tipredominan Aa.

I)SUBSTITUIT (AA. secundara aminica functia cu Aa.

ROL

NH

COOHOH

hidroxi-prolina

AMINOACIDMONOMER mic;n ulare;macromolec Subst.

glu-CO-NH-lys-CO-NH-CysPEPTIDICA leg.1002aaacondensarenat. Subst.

aa) 100(10 EPOLIPEPTIDaa) 10( DEOLIGOPEPTI

PEPTIDE

aa) (9 enonapeptideoctapeptiddeheptapeptiehexapeptiddepentapepti

aa) (4 detetrapeptiaa) (3 tripeptideaa) (2 dipeptide

Oligo

esemiciclic pept. 4)ciclice pept. 3)ramificate pept. 2)liniare pept. 1)

libere

SHOH

2NHCOOH

gr. prezenta

aminoacizidesecventa;NHCOprezenta

H2N COOHCH

R1R2

+ H2N COOH

H2O

CH

aa 1 aa 2

R3H2N

R1

CO NHCH

R2

COOHCH

H2O

H2N COOH

dipeptida

CH

H2N

R1

CO NHCH

R2

CH CO NH

R3

COOHCH

tripeptida

H2O

(n-3) aminoacizi

H2N

R1

CO NHCH CH CO NH COOHCH

RiRn

n-2

polipeptidai = 2,3......n-2

aa

)(peptidaze ENZIMATICAACIDA

A3)HIDROLIZ

HOH tesolubilita 2)AMFOTERcaracter 1)

triptofancisteinilleucilvalilalaniltirozil

trpcisleuvalalatyr

:Exemplu

aa finalcompleta denumirea il""aa de Rest

4) Reactia BIURETULUI

O = CNH2

CuSO4

2 NaOH

HN

H

N

O

NH2- NH3 O = C

O = CNH

NH2

NH2

NH

O = CNH2

NH2

C

O

C N

H

Cu

H

N

N

H

O

C

O

C

biureturee

complex cuproalcalinic (culoare violet)

-2

2 Na+

CH

NH2

HOOC CH2CH2 CO NH

CH2

CH

SH

CO NH CH2 COOH

GLUTATION

( GAMMA-glutamil-cisteinil-glicina)

H

COOH

NH2 CH

CH2

CH COOHNH2

SH

CH COOH

NH2

HOOC CH2CH2

acid glutamic

+ +

cisteina H2O2

CH

NH2

HOOC CH2CH2 CO NH

CH2

CH

SH

CO NH CH2 COOH

glutation redus( GAMMA-glutamil-cisteinil-glicina)

glicina

-legtur peptidoid

CH

NH2

HOOC CH2CH2 CO NH

CH2

CH

SH

CO NH CH2 COOH2

- 2 H+ - 2e-

glutation redus

CH

NH2

HOOC CH2CH2 CO NH

CH2

CH CO NH CH2 COOH

CH

NH2

HOOC CH2CH2 CO NH

CH2

CH

S

CO NH CH2 COOH

S

glutation oxidat

G-SH G-S-S-G2-2 H

+2 Hglutationredus

glutationoxidat

- particip la reaciile redox celulare conform reaciei

- joac rol de coenzim( donor de H):

G-SH+A 2 AH2 + G-S-S-G

ox1 red2 red1 ox2

metabolice deseuri

exenobioticedetoxifier la participa

)(OH hidroxil R.

)(O hidrogen de Peroxidul

)(O Superoxid

)O(singlet Oxigen

(RLOt antioxidan ca actioneaza

dependente SHenzime activeaza

.

22

.2

21

2

CONJUGAZASGLUTATIONenzimaticacataliza

solubili)CONJUGATI(GLUTATIONOSHG cu conjugarea

EDETOXIFIER dea aII FAZA

Nonapeptide secretate de lobul posterior al HIPOFIZEI

Vasopresina

H2N - Cys -Tyr - Phe - Gln - Asn - Cys - Pro - Arg - Gly - CONH2

S S sau Lys

Ocitocina

H2N - Cys -Tyr - Ile - Gln - Asn - Cys - Pro - Leu - Gly - CONH2

S S

1 2 3 4 5 6 7 8 9

icantidiuret

vaselor) (contr.v hipertensiaVasopresin

lactatia

uterine musc. contractiaOcitocina

Lys

ArgLeu:8 pozitia

PheIle:3 pozitia

ACTIONEAZA

STIMULAREA

INLOCUIRE

INLOCUIRE

le functionaDeosebiri

estructural Deosebiri

ticiCaracteris

rarenalacorticosup

a)biolologicfunctia a(invariabil secv.aa 24

anterioarahipofiza

STEROIZI H. DE SECRETIA STIMULA:Functia

variabila secv.aa 15aa 39:compozitie

de secretat

cys19(B)cys20(A)

cys7(B)cys7(A)B si A intre SS 2punti

bazici aaaa 30B catena

cys11)(cys6 SS 1punte

bazici aa21aaA catena

(octamer) 48000

(tetramer) 24000

(dimer) 12000

(monomer) 6000

:MM

de secretat

Structura

IANTHIPOGLICEM H.:Functie

pancreas

MIANTHIPERGLICE

insulinei al antogonist

unica

aa 29Structura

de secretat

Functie

pancreas

ticiCaracteris

cuaternarastructura

tertiarastructura

undarasecstructura

primarastructura

obaleg.hidrofd)

hidrogenleg.dec)

leg.ionicab)

hidricaleg.disulf b)peptidica leg.a)

secundara str.

aa) de (secv. peptidica leg.:primara str.

LEGATURI

a

a '

C

NH

C

CO

a

a '

C

NH

C

CO

+

-

a

a '

C

NH

C

CO

a

a '

C

NH

C

CO

+

-

naturale proteineTRANSforma

NC raport in )siC(C transcis izomerie

coplanari

C

H

O

C

C

implica

PEPTIDICE LEG. TICELECARACTERIS

α'α

α'

α

3 posibiliti de dispunere spaial a planurilor formate prin legturi peptidice succesive ale unei catene peptidice

1) Planurile succesive alterneaz unul fa de altul conform a dou orientri spaiale privilegiate => structura "n foi plisate“ (structur de tip periodic);

2) Planurile succesive se rotesc regulat,totdeauna n acelai sens unul n raport cu cellalt => structura de "form helicoidal" (structur de tip periodic);

3) Planurile se pot roti la ntmplare unul fa de altul => structura "n ghem statistic" (structur de tip neperiodic).

R

O

N

H

H

H

C

1

2

34

N

CO

RH

N

C

H

Structura teriar a globinei din mioglobin

Structura cuaternar a colagenului, protein fibrilar cu rol de susinere.Lungile catene polipeptidice ale colagenului sunt dispuse sub form de triplu helix. Structura cuaternar a hemoglobinei, protein globular,ce comport 4 catene polipeptidice i 4 molecule de hem. Oxigenul se ataeaz la structura hemoglobinei prin fierul hemului.

H) atom (MMg 1,67x101dalton

daltoni miloanemiiMM24

Masa moleculara

Insulina (MM = 6.000); Ribonucleaza (MM = 13.700); Ureaza (MM = 480.000)

Masa moleculara

.insolbcompletproteine

;alcalinesolinsolbproteine

;acidesolinsolbproteine

;ielectrolitdesolin.solbproteine

;apain.solbproteine

Solubilitatea

guanidinasiurea

.org.solv

acizii

ionizantesiUVradiatii

caldura

Denaturarea

ionica leg.

H de leg.

SS leg.

idisparitie consecinta

primara str. afectata este nu

spatiale str. areadezorganiz

Definitie

Agenti de denaturare

Denaturarea reversibil a ribonucleazei

osmotica presiune

culoare de reactii

evascozitat

modificare

efunctional grupari noi de aparitia

hidratare de icapacitati pierderea

tiisolubilita diminuarea

biologice iactivitati pierderea

IDENATURARI NILEREPERCUSIU

Caracter coloidal

Caracter amfoter

n sol. diluate =>coloii hidrofili (1-100 m) n sol. concentrate => micele

H2NPROTEINAH3N COO+

- PROTEINA COO- + H+PROTEINAH3N

+COOH

pH=7pH=1pH=11

cation zwiterion anion

CONSECINTA: nu dializeaza prin membrane

Punct izoelectric (pHi)

6,10citocrom

9,6]Hb[pH

1]asinpep[pH

c

i

i

=>separarea, purificarea proteinelor

fanere)(piele, keratina

tendoane)nctiv,(tes.conju colagen

fibroina

einescleroprot

FIBROASE PROTEINE

globuline

albumineinesferoprote

GLOBULARE PROTEINE

natropomiozid)

troponinac)actinab)

miozinaa)

rilare7)Prot.fib

oteine6)Scleroprglutelinee,5)Prolamin

4)Globinehistonee,3)Protamin

e2)Globulin1)Albumine

inecromoprote

einenucleoprot

nelipoprotei

ineglicoprote

inefosfoprote

EINEHETEROPROT

)aa(:NEHOLOPROTEI n

proteine colorate; gruparea prost.

MgCuFe

Definitie

ornerespirat,respiratorrolicaneporfirina,porfirinic str.

Clasificarea cromoproteinelor

](Mg)[clorofilaineCloroplastr

Catalaze

PeroxidazehemininiceEnzime

)(hemCitocrom

)(hemCtocrom

)(hemCitocrom

Citocromi

eHemoglobin

..

nerespi Pigm.

(Fe)respir Pigm.

cc

bb

aa

porfirCr.

minaCeruloplas

naHemocupreiCu

naSiderofili

FeritinaFe

eineMetaloprot

ineFlavoprote

vit.A

arotenβc

arotenαc

oteineCarotenopr

(Cu)eHemocianin

(Fe)eHemiretrin.

pir.Pigm.neres

rPigm.respi

neporfirCr.

Hb = HEM(4%) + GLOBINA(96%)

HEM = protoporfirin + fier

4 nuclee pirolice + =CH- PORFINA

PORFIRINEClade)8(Hasubstituti

PORFINA

NAUROPORFIRI

COOH2

CH2

CHCOOH,2

CHcuesubstituti

PORFINA

HEMATINE

:Exceptie

HEMIPORFIRINE

IRINEMETALOPORF)Mn,Mg,Co,Fe(PORFIRINE

3Fe PORFIRINE

2Fe

IRINA)(PROTOPORFPROTOHEM

metale

CH

HN

H

H H

H

HC

CH

HN

N

N

HC

H

H

H

H

1 2

34

56

7

8

I

II

III

IV

Atomi de carbon si

Atomi de carbon si

'

'

Structura porfinei

HNHN

N

N

1 2

34

56

7

8

I

II

III

IV

CH3

CH2

CHCH3

CH CH2

CH3CH2

CH2

COOH

CH3

HOOC CH2 CH2

Structura PROTOPORFIRINEI

Globina = compon. proteic )(

patologicast.

speciavarsta

iazastruct.var

HEM4)aa146(

)aa141(2icepolipeptidcatene4globina

icapolipeptidcatena1globina

aHemoglobin

Mioglobina

HEM4)aa131(2

)aa141(2peptidicecatenepoli4globina

Hb.FETALA

F2

A2

A2

A2

γαHbF

βαHbA

falciformaanemia

secventadeanomalie

catenederepartitie

catena

valgluEx

catena

catena

APHb

APHbEx

)6()6(:

4.

4.:

Hb.P

obina)(oxihemogl HbO4OHb 4224

4]COHb[CO44]Hb[

1) Combinarea cu oxigenul = oxihemoglobina

2) Combinarea cu CO = carboxihemoglobina

3) Combinarea cu CO2 = carbhemoglobina

OHCONHoteinaPr2NHoteinaPr2CO

ROTEINECARBAMINOPCOsanguine Proteine 2

4) Oxidarea reversibila a Hb = METHEMOGLOBINA

a)ferocianurreducator()3BINA(FeMETHEMOGLO

)ricianuraOxidant(fe)2Hb(Fe