Τόμος Βιοχημείας 1 - Ένζυμα
DESCRIPTION
Εισαγωγή στα Ένζυμα.TRANSCRIPT
-
. . () .
, S, .
. . . .
29. .
22
-
. . (), , , . , . .
- (S). .
k1 k3( kcat) + S ES E + P
k2
. . .
23
-
. . .
3036.
. . . . , , .
24
-
. , - . - . . .
:
1. ( reduce = )
.
.
.
NADH H+
.
25
-
+ NAD+ + NADH H+
.
22.
22 22 2
2.
.
.
:1.1. CHOH,
1.2. -
1.3. CH-CH-
1.4. CH-NH2 1.5. -CH-NH-
1.6. NADH, NADPH
1.10.
1.11 H2O21.12.
1.14.
26
-
1.7.
1.8.
1.9.
1.15
1.16.
1.17 CH2-
. 1.1
, -CHOH,
: 1.1.1. NAD+ NADP+,
1.1.2.
11.3. O2
1.1.99.
2.
.
.
.
-CH3, -COOH,
CO-R, NH2 .
, , -
27
-
, .
(),
GTP.
:
.
,
:2.1. (-, -,
-)
2.2.
2.3.
2.4.
2.5.
2.6.
2.7. ()
2.8.
28
+ +
-
3.
. ,
.
CO-
.
R-CO-O-R.
.
(C-O-PO3H2).
(-O-PO2H--).
.
29
-
DN, RN
DNA, RNA .
3.1
(, , ,
)
,
:3.1 (, ,
, )
3.2 -
3.3
3.4.
3.5. C-N ( )
3.6.
3.7 . C-C
3.8. C-X, P-X
3.9. P-N
3.10. C-P
4.
.
CO2
(-COOH)
30
-
. (-CH2-CH2-COOH
-CH=CH2 + CO2 ).
.
,
:4.1. C-C 4.2. C-O 4.3. C-N
4.4. C-S 4.5. C-X 4.6. P-O
4.99
5.
.
, cis- trans- ,
.
cis- trans-
:5.1. ,
5.2. cis-trans
31
C = CH H
R1 R2
C = CH
HR1
R2C = C
H H
R1 R2
C = CC = CH H
R1 R2
C = CH
HR1
R2C = CC = C
H
HR1
R2
CR3
R1H R2 C
R3
R1R2 HC
R3
R1H R2C
R3
R1H R2 C
R3
R1R2 HC
R3
R1R2 H
-
5.3. (
C=C, S-S,)
5.4. ( ,
, ..)
5.5.
6.
.
, ATP,
, GTP, .
,
:
6.1. C-O 6.2. C-S
6.3. C-N 6.4. C-C
6.5. -
:
32
-
1.
. :
NAD+ : --NADP+ : ---
NAD+ :
S2 + NAD+ S + DH + H+
S2 .
NADP+
S2 + NAD+ S + DH + H+
. : FMN - FAD
S2 + FMN+ S + FMNH2 S2 + FAD+ S + FADH2
. . . . . ( C)
2.
33
-
. P ( ): : , , (), ()
. (CoA) : (COCH3). : . : (CH3). ( , c):
: (CH3), (-CH2OH), (-CHO)
. ( ) : (COOH). CO2
. ( 1 ): . ( B6) :
(2) (COOH).
3. , ,
12 .
.
,
34
-
.
.. -
.
Enzyme
Commission EC
. , 1.1.1.1
.
1 : .
.
1.1. :
1.1.1.
NAD NADP
.
1.1.1.1
.
35
-
1. pH
. , - , . , pH . pH . pH . , pH . pH pH .
31. pH
36
pH
pH
-
, . : pH , pH , .
, , , , , , . (pH 4-6) : . . . . . . ( pH 5-7) . , .
37
-
(pH 10) . , , , , . , . , . . .
2.
, . . , . 50C. . 90C 60 70C .
38
-
3265.
6- (G6PD) . . . . . , G6PD.
3. .
39
=C
t
=C
t =
C
t
-
. , , .
33.
. .
4. .
32.
40
(mM)0 50 100 150 200 250 300 350
120
100
80
60
40
20
0
%
(mM)0 50 100 150 200 250 300 350
120
100
80
60
40
20
0
%
-
. , . , . S.
3436. Michaelis-Menten
Michaelis-Menten. . Michaelis :
[S] V = Vmax Km = k2 + kcat / k1 [S] + Km
, Vmax, ,
41
-
- . Vmax . V=Vmax/2 m, m=[S]. , Km( Michaelis), V=Vmax/2. m . . m . Vmax m . Km Vmax ( pH, , , ). Vmax/Km. . Vmax , kcat/Km . , . []=[S] (Vmax) S.
42
-
kcat[ES] E + P
([E]=[ES])
Vmax = kcat [ES] Vmax = kcat [E] kcat = Vmax/ [E]
kcat ( min sec) . mole/L.sec kcat sec-1, sec sec . O kcat/Km Vmax/Km kcat/Km = (Vmax/Km)/[E].
. .
Lineweaver-Burk , 1/v 1/S. , Km Vmax.
3536. Lineweaver-Burk
43
-
Km
, . , Km Km.
. . Km ( ) . .
5. .
44
CH3CH2OH + NAD CH3CHO + NADH2CH3CH2OH + NAD CH3CHO + NADH2
-
. . . .
. .
. . , - , , . .
, ()
+ , : H , , .
45
-
. ,
. . , , . , Km Vmax.
36. . : , : , :
.
. ,
. Vmax Km .
46
YY
A A
E
E
E
YY
A A
E
E
E
YY
A A
E
E
E
-
37.
.
. Vmax () Km ( ).
. ,
- S + I ESI . Km Vmax.
38.
, . .
47
A
A
A
A
A
A
A
AY
Y
Y
Y
Y
Y
YY
Y
YY
YY
Y
YY
-
.
. . (feedback inhibition), .
, L- L-, , L- 2 .
1 2 3 4 5L- L-
.
. . .
Mg2+, Mn2+, Ca2+, Ni2+, Zn2+ . .
48
-
. . , , . .
. . , . . . . . . .
49
-
.
39 65, 66.
.
1- , , . (). . glu342 Lys ( ), Lys342 Glu . .
50
-
.
, (Mevinolin,
Mevastatin, Lovastatin) 3--3-
--CoA (HMG-CoA )
. ,
.
. , . .
6.
,
51
-
. , , Vmax = kcat . [E]
40.
41. .
52
0 t
[P]
0 t
[P]
[S]
v
[S]
v
-
. , . () . ( pH).
. . , . . .
.
53
-
Vmax.
, , . . .
. . . . . , .
54
S PE
S PE
= = [P] [S]t t = = [P] [S]
t t
-
, . NAD NADP. NADH2 NADPH2 340 nm . FAD. 450 nm FADH2.
42. NAD FAD.
55
P1 P2E2
S P1E1
P1 P2E2
P1 P2E2
S P1E1
(nm)
(nm)
-
o (mole) . , (=mol / ) . ( pH ), . . (International Unit, IU, Unit, U).
56
COOH
H C NH2CH3
COOH
C O
CH3
COOH
H C NH2CH2CH2COOH
COOH
C O
CH2CH2COOH
+ +GPTCOOH
H C NH2CH3
COOH
H C NH2CH3
COOH
C O
CH3
COOH
C O
CH3
COOH
H C NH2CH2CH2COOH
COOH
H C NH2CH2CH2COOH
COOH
H C NH2CH2CH2COOH
COOH
C O
CH2CH2COOH
COOH
C O
CH2CH2COOH
+ +GPT
+ - + + - +
COOH
C O
CH3
COOH
H C OH
CH3
+ NADH H + + NAD+
COOH
C O
CH3
COOH
C O
CH3
COOH
H C OH
CH3
COOH
H C OH
CH3
+ NADH H + + NAD+
+ NAD + + NAD+340
+ NAD + + NAD+340
340 nm
-
Katal. katal mole .
mg katal kg . . .
. mole katal mole .
. Km Vmax . . .
57
-
, .
.
. , , , . . .
. , SDS . 30 . , .
, .
58
-
.
, , , , .
. . (heart), 4. (muscle), 4. 3, 22, 3. 4 4 .
. . 1:
. 2-5: . 2: , 3: , 4: , 5: .
(lactate dehydrogenase, LDH) . LDH . .
59
-
43. (CPK), (LDH) - (DH) .
. , . . .
60
-
, . . , .
. ,
. pH 5,
44 .
, ,
(, ,
) .
.
.
, -
61
-
-
.
-
-
.
44.
, pH, , , , .
.
, . ( ). . .
62
-
, . . .. , , . pH, . .
63