Page 108 - Color Atlas of Biochemistry

Enzymes 99

A. Lactate dehydrogenase: structure

Lactate
Pyruvate dehydrogenase Lactate
1.1.1.27

NADH + H NAD

N A N A

1. Tetramer 144 kDa

2. Active center
Substrate Mobile Coenzyme
Essential (lactate) loop (NAD )
amino Enzyme
acids protein
Arg-109
His-195
Arg-171

B. Isoenzymes
Lactate dehydrogenase M
RYLMGERLGVHPLSCHGWVLGEHGDSSVPVWSGMNVAGCSLKTLHPDL GTD..
1. Gene
RYLMAEKLG IHPSSCHGW I LGEHGDSSVAVWSGVNVAGVSLQELNPEMGTD..
Lactate dehydrogenase H

LDH1 (H ) Skeletal muscle
4
LDH2 (M H )
1 3
Liver
LDH3 (M H )
2 2
Brain
LDH4 (M H )
3 1
Cardiac muscle
LDH5 (M )
4
LDH5 LDH4 LDH3 LDH2 LDH1
2. Forms 3. Separation by gel electrophoresis

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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