biochemistry lecture enzyme

8/10/2019 Biochemistry Lecture Enzyme

1/126

Enzyme

TS. Trng Quc Phong


2/126

1. Khi nim v enzyme

Enzyme l g ?

Enzyme l nhngprotein c khnng xc tc c hiucho cc

phnngha hc

- L cc chtxc tc sinh hc

- ctora trong cc hthngsng- Xc tc cho cc phnngxyra trong chthngsngv xyra

ngoi tbo (in vitro)

- Hottnh xc tc mnh

- iukinxc tc n ha

- Phnngenzyme c khnng iukhinc

- Ngoi enzyme c bn cht l protein, c nhng enzyme c bn

chtl ARN, gil zibozyme


3/126

1. Khi nim v enzyme

ngdngenzyme:

- Khng tch khinguyn liu

- Tch enzyme khinguyn liudngchphm

Enzyme csdngtrong nhiulnhvckhc nhau

+ Nghin cucutrc phn t:

Proteaseprotein

Endonuclease cutrc axit nucleic

+nhlngcc chttrong nng nghip,cng nghipvy hc

Urease nhlngure trong nctiu

Amylase nhlngtinh bt

Glucosooxidase nhlngglucose


4/126

1. Khi nim v enzyme

ngdngenzyme (tip):

Trong nng nghip

Sdngenzyme trong chbinthcncho ngvt

Trong cng nghip- Cng nghipdt

- Cng nghipda

- Cng nghipchbinthcphmlm tngnhanh qu

trnh chbin,tnghngvv gi trdinh dng

Trong y hc

- Lm thucchabnh,snxut1 sthuc,...


5/126

1. Khi nim v enzyme

Hottnh xc tc caARN

Ribonuclease P (ARN + protein):

- pre-tRNAtRNA

-chphnRNA c hottnh xc tc (nuclease)

- RNA c cha: trung tm hot ng, tnh c hiu c cht, to

thnh phc trung gian vi c cht, ng hc xc tc tun theo

phng trnh MichaelisMenten,...

Qu trnh tctkhng cnprotein:

- pre-rRNArRNA

- Tm thynhiusinh vt: ty th,nmmen, nmmc,lclp,...

Hottnh: xc tc cho phnngctniARN thng qua schuyn

v este phosphate, chuyn v phosphoryl, hoc thy phn nhm

phosphate


6/126

1. Khi nim v enzyme


7/126

1. Khi nim v enzyme


8/126


9/126

1. Khi nim v enzyme


10/126


11/126

2. Cu to ha hc ca enzyme

1.Bnchtprotein caenzyme:- Enzyme c ytnh chtgingnhprotein:

+ tnh ha tan

+ tnh knc+ tnh chtdung dchkeo

+ khnngbintnh v sktta

+ tnh lngtnh+ tnh chtthyphn,...


12/126


1.Bnchtprotein caenzyme (tip):- Enzyme mt thnh phn v enzyme hai thnh

phn:

+ Enzyme mtthnh phn: chchaprotein

+ Enzyme hai thnh phn(holoenzyme):

protein (apoenzyme) + nhm ngoi (coenzyme

hoc/vcofactor)


13/126


1.Bnchtprotein caenzyme (tip):

- Hthngnhiuenzyme:

+ gmcc enzyme xc tc cho mtdy chuynphn

ng

+ cc enzyme trong hthngc thtntiring rdngha tan, hockttvinhau

+ mt s h thng enzyme c th lin kt vi cc

mng, cquan tcatbo

E1 E2 E3A B C D


14/126


2. Trung tm hotngcaenzyme:- Trung tm hotngl g?

L mt phn nh ca phn t enzyme cha cc

nhm chc trc tip kt hp vi c cht, tham giatrctiptrong vichnh thnh, cttcc lin kt,...

tothnh snphmphnng.


15/126


2. Trung tm hotngcaenzyme:

-cimcaTTH:

+ Chchimmttlthtch tngib caphn

tenzyme

+ Gm nhiu nhm chc khc nhau ca cc axit

amin, phn t nc lin kt, ion kim loi, nhmchccacoenzyme


16/126



17/126



18/126


19/126



20/126

4. C ch tc dng ca enzyme

2-phosphoglycerate Enolic intermediate

Phosphoenolpyruvate


21/126



-cimcaTTH:

+ Nhm chccatm xc tcv mintipxc

+ S tng ng v cu hnh khng gian giaTTH v c cht c hnh thnh trong qu

trnh enzyme tipxc viccht


22/126


2. Trung tm hot ng ca enzyme:Thuyt kha v cha kha (Emil Fischer)

Thuyt tip xc cm ng (Daniel Koshland)


23/126


2. Trung tm hot ng ca enzyme:


24/126


2. Trung tm hotngcaenzyme:- GiaTTHv ccht to thnh nhiu tng tc yu

ddng bctttrong qu trnh phnnggii

phng enzyme v snphm

- TTHcaenzyme c cu trc bc4 c thnm trn

mtphndinvhocgmcc phndinv

khc nhau


25/126



26/126


- Enzyme dlpth(alosteric):


27/126



- Mt s enzyme c TTH tn ti di dng cha c hot ha

(zymogens): pepsinogen, trypsinigen, chymotrypsinogen,...


28/126


29/126


Mtscimchung caqu trnh hotha Zymogen:- L qu trnh thy phn gii hn protein, ct t mt hoc

mtslin ktpeptide uN caphn tzymogen

- Lm thay icuhnh khng gian caphn ttheo hng

c licho hotngxc tc, tothnh phn tenzyme

- Hiusuthotha zymogen ph thucvo iukinhot

ha, nng zymogen, bn cht v nng enzyme, to,

pH,...

C


30/126


2 C h h


31/126


2. Coenzyme:

- Coenzyme l g?

L thnh phn khng phi protein ca phn t

enzyme c vai tr xc tc cho mtphnng ha

hc

2 C t h h


32/126


2. Coenzyme:- cimcacoenzyme:

Quytnhkiuphnm enzyme xc tc

Trctiptham gia trong phnng Lm tng bn ca apoenzyme i vi cc

yutgy bintnh

Thng l dn xut ca cc vitamin ha tantrong nc

2 C t h h


33/126


2. Coenzyme:

Coenzyme l dn xut ca Vitamin:

Coenzyme VitaminChemical group(s)

transferred

NAD+and NADP+ Niacin (B3) Electrons

Coenzyme A Pantothenic acid (B5)Acetyl group and other

acyl groups

Tetrahydrofolic acid Folic acid (B9)Methyl, formyl, methylene

and formimino groups

Menaquinone Vitamin KCarbonyl group and

electrons

Ascorbic acid Vitamin C Electrons

Coenzyme F420 Riboflavin (B2) Electrons

2 C t h h


34/126


Coenzyme Chemical group(s) transferred

Adenosine triphosphate Phosphate group

S-Adenosyl methionine Methyl group

3'-Phosphoadenosine-5'-phosphosulfate Sulfate groupCoenzyme Q Electrons

Tetrahydrobiopterin Oxygen atom and electrons

Cytidine triphosphate Diacylglycerols and lipid head groups

Nucleotide sugars Monosaccharides

Glutathione Electrons

Coenzyme M Methyl group

Coenzyme B Electrons

Methanofuran Formyl group

Coenzyme khng l dn xut ca Vitamin:

2 C t h h


35/126


2.2. Coenzyme:

- Cc dng coenzyme:

+ Coenzyme ca enzyme oxy ha kh: NAD, NADP,

FAD, Ubiquinon,

+ Coenzyme ca cc enzyme vn chuyn:

- Coenzyme A, axit lipoic,...

- Biotin, Thiamin pyrophosphate, pyridoxal

2 C t h h


36/126


2.3. Cofactor:

L thnh phn ha hc b sung c mt trong mt s enzyme

3 T h ht


37/126

3. Tnh cht ca enzyme

3.1. Cnglcxc tc:

- C cng lcxc tc mnhhnnhiuso vichtxc tc

thng thng

1 M Fe3+ xc tc phn ly c 10-6M H2

O2

/pht. Trong

khi, 1 phn t catalase xc tc phn ly c 5.106 M

H2O2/pht

1g pepsin c ththyphn c5 kg protein trng luctrong 2h, RT

3 T h ht


38/126


3.2. Tnh c hiu ca enzyme:Mi enzyme ch c kh nng xc tc cho s chuyn hamthay mtschtnhtnhtheo mtkiuphnngnht

nhtnh chiucaenzyme

c hiu kiu phn ng

Mienzyme chc thxc tc cho mttrong cc kiuphn

ngchuynha mtchtnhtnh

C ki h


39/126

Cc kiu phn ng

1. Oxi ha kh

2. Chuyn v

3. Thy phn4. Lyase

5. ng phn ha

6. Ni ghp

3 Tnh cht ca enzyme


40/126


2. Tnh c hiu ca enzyme:

c hiu c cht

Cchtl g:l chtc khnngkthpvo TTHca

enzyme v b chuyn ha di tc dng

caenzyme


41/126

3 Tnh cht ca enzyme


42/126


1. Tnh chiucaenzyme:

chiunhm tuyti:

-Ch tc dng ln cc cht c cng mt kiu cu trc

phn t,mtkiulin kt,v c nhngyu cuxc nh

ivinhm nguyn tgnlin ktchutc dng

- V d: mantase, chxc tc thyphn lin kt glucoside

(OH glucoside ca-glucose vi OH ca mt monose

khc)

3 Tnh cht ca enzyme


43/126


1. Tnh chiucaenzyme:

chiunhm tngi:

- Enzyme khng ihig nghim ngtivinhm

gnlin ktbphn gii

- V d: Lipase xc tc cho phnngthyphn lin kt

este trong lipid. Aminopeptidase xc tc cho phnng

thyphn lin ktpeptide


44/126

4 C ch tc dng ca enzyme


45/126


E + S ES E + P

1. Cc giai on:

- Enzyme kthpviccht thng qua cc lin ktyu

tothnh phcenzymecchtkhng bn

- Sbinicchtko cngv ph hycc lin kt

ngha trtrong phn tccht

- Tothnh snphmv giiphng enzyme tdo



46/126


1. Cc loilin ktgiaE v S: Tngtc tnhin:

- Tothnh gianhm tch incacchtvinhm tch

intri dutrong phn tenzyme

O H2N

+H3NGlyTyrC CNCH2CH2CH2 - E

O- H2N+



47/126


1. Cc loilin ktgiaE v S: Lin kthydro:

- ctothnh theo kiu:

AH ... B- Hydro kthpviA bnglin

ktcngha tr,ngthi

lin ktyuviB- Khi khongcch gia

A v B = 3



48/126




49/126


1. Cc loilin ktgiaE v S: Tngtc Van der Waals:

- Yu v t c hiu hn tng tc tnh in v lin kt

hydro- Tngtc ny thhinr khi nhiuphn tcaccht

c thngthitipcnvinhiuphn tenzyme

Cc tngtc khc:- Tng tc kncgiacc nhm khng phn ccca

phn tcchtv phn tenzyme ngvai tr quan

trngtrong qu trnh cunlicacc phn tln



50/126


Cchtc dngcaenzyme Carboxypeptidase:- Xc tc cho phnng thyphn lin ktpeptide uC

cacc polypeptide v protein

-Phnngxyra vitc lnnuaxit amin uC l axitamin thm

- Zn tham gia trong hotngxc tc caenzyme

- Cc axit amin c vai tr xc tc trong TTHcaenzyme:Arg-145 , Tyr-248 v Glu-270


51/126



52/126


Cchtc dngcaenzyme Carboxypeptidase:

Tothnh phcES:

Tngtc giacc nhm chccaTTHviglycyltyrosine:

- Nhm COO- tdo cacchtkthpvinhm tch in

dngcaArg-145 caenzyme thng qua lin kttnhin

- Nhm NH trong lin kt peptide ca c cht to thnh

lin kthydro vinhmOH caTyr-248

- Oxy trong nhm CO ca lin kt peptide ca c cht

tngtc viZn, cn Carbon trong nhmCOny tng

tc vinhm COO-caGlu-270 qua phn tnc


53/126



54/126


C ch tc dng ca enzyme Carboxypeptidase:

Cttlin ktpeptide giiphng snphm:

- Nguyn tZn phn cclin ktCOtngi lcintca

nguyn tC trong nhmCOtngtngtc can viH2O

-GcGlu-270 hotha H2O to thnh OH- tncng trc tip

vo C caCOtrong ccht

-ng thi, tng tc tnhingianhm COO-(uC) cac

chtvinhm NH3+caArg-145 caenzyme

Lin ktpeptide bko cngra v bt

- Nguyn t H c chuyn t gc Tyr-248 ca enzyme sang

nhmNHtrong lin ktpeptide caccht



55/126


Cchtc dngcaenzyme Chymotrypsin:



56/126



57/126



58/126



59/126



60/126




61/126




62/126




63/126


2-phosphoglycerate Enolic intermediate

Phosphoenolpyruvate


64/126


65/126


66/126

5. Cc yu t nh hng n vn tc phn ng enzyme


67/126

y g p g y



68/126

y g p g y

5.2. Nngccht:

v =

-Nu[S] > Km, v = V, tcphnngtcci,khngphthucvo [S]

-Nu[S] = Km, v = V/2, tcphnngbng1 natc

cci

V [S]

Km+ [S]


69/126



70/126

HngsKm

- Do Km= [S] khi v = V,tr s ca Kmcngcbiudin

bng n vo nngc cht: mol, gam, %

- Km

= 10-110-6

- iviphnln enzyme,c thcn c vo Km nhgi

ilcgia enzymevc cht

- iukinxcnh (to, pH,...), Kmca 1enzymeivi 1c chtl hngs

Xc inh Km c ngha quan trng trong nghin cu

enzyme



71/126


72/126



73/126

Lu khi xc nh ng hc phn ng enzyme:- S dng ch phm enzyme tinh khit

- Nng c cht khng nn qu ln



74/126

Km biu kin

Enzyme allosteric

Km biu kin


75/126


76/126



77/126

3. nhhngcacc chtkm hm:

- Hotcaenzyme c thbthay iditc dngcamts

chtc bnchtha hckhc nhau

- Cc chtlm gimhotenzyme gil cc chtkm hm

- Cc chtkm hm: ion, cc phn tv c,huc(protein)- C vai tr trong qu trnh iuha, kim tra cc qu trnh trao

ichttrong hthngsng

- C thlm bintnh hockhng gy bintnh protein

- Skm hm c thl thunnghchhockhng thunnghch

k+iE + I EI

k-i



78/126

Km hm cnhtranh:

E


79/126


80/126



81/126

Km hm khng cnhtranh:



82/126

4. nhhngcacc hotha:

- Cc chtny lm tnghotxc tc caenzyme

- Cc chthotha:

+ anion: Cl, Br, I-amylase

+ ion kim loi: Mn2+, Zn2+,...protease

+ cc chthucphctp

- Cc cht hot ha thng kt hp trc tip vi phn t

enzyme lm thay icuhnh khng gian caenzymetheo hngc licho hotngxc tc

- Ngoi ra, mtschtc th tc dnggin tipthng qua

loibcc yutkm hm


83/126


84/126



85/126

6. nhhngcapH:

-nhhngr rtnphnngenzyme:

+ nhhngnmcion ha ccht,enzyme

-nhhngnbncaenzyme

+ asenzyme bntrong phpH=5-9

+ bn tng ln khi c c cht, coenzyme, cofactor

(Ca2+)


86/126


87/126


88/126

6. Cch gi tn v phn loi enzyme


89/126

Phn loi quc t

S Lp Kiuphn ng xc tc

1 Oxidoreductases Oxy hakh

2 Transferases Chuyn v3 Hydrolases Thyphn4 Lyases Phn ct khng cn nc5 Isomerases ng phnha6 Ligases Ni ghp:C-C, C-S, C-O, C-N



90/126


91/126


92/126


93/126


94/126



95/126

1. Oxidoreductase

Dehydrogenase:

Alcoholdehydrogenase

CH3CH2OH + NAD+

CH3CHO + NADH + H+

c vai tr quan trngtrong qu trnh ln men ru

Glutamatedehydrogenase

L-glutamic + H2O + NAD+-ketoglutaric + NH3+

NADH + H+

chuynN v cttvo TV, gip VSV hpthNH3



96/126

1. Oxidoreductase

Reductase:

Xc tc cho qu trnh chuynintnoxy, lm cho oxy

c khnngkthpviproton

4 Ferocytochrom c + O2+ 4H+= 4 Fericytochrom c + 2H2O

Oxygenase

Xc tc cho cc phnngoxy ha, trong nguyn toxyc kt hp vo phn t c cht to thnh nhm OH,

COOH



97/126

1. Oxidoreductase

Peroxydase:

- Bao gmPeroxydase inhnh v Catalase

- C coenzyme l hem

- Xc tc cho phn ng oxy ha cc cht hu c khi c

H2O2

Peroxydase:

Cht cho + H2O2= cht cho b oxy ha + H2O

Catalase:

H2O2 + H2O2 = O2 + 2H2O


98/126



99/126

3. Hydrolase

- Xc tc cho phnngthyphn

- Khng cncoenzyme cho hotngxc tc

- C vai tr quan trngtrong qu trnh tiu ha

- V d:

+ Amylase: -amylase, -amylase, glucoamylase

+ Peptide hydrolase

+ Lipase


100/126


101/126


102/126


103/126

7. Cc ngun thu enzyme


104/126

3. Vi sinhvt

Vi khun (bacteria) Nm men (Yeast)
http://www.coll-outao.qc.ca/bio/Imagebiologie/imagemicrobiologie/Bacterie%20flagelle.jpg


105/126


106/126

8. Sinh tng hp enzyme


107/126


108/126



109/126


110/126


111/126


112/126


113/126



114/126


115/126


116/126


117/126

S hnh thnh phc khi u


118/126



119/126



120/126


121/126


122/126


123/126


124/126


125/126


126/126

biochemistry lecture enzyme

Documents