1 Flashcards
Transfer of an amino group between aspartate
and α-keto acids
• Involved in the synthesis and degradation of AA.
• Widely distributed, highest activities in cardiac, liver
and skeletal muscle
Aspartate Aminotransferase (AST)
2 isoenxzyme:
______- most abundant / predominant in healthy human serum
________type: present in the mitochondrial membrane = inc. in serum= necrosis
Cytoplasmic
Mitochondrial
: enzymes with similar catalytic activity but defer in the physical and biochemical and immunologic properties
isoeznyme
Aspartate + a- ketoglutarate —- _____ ——oxaloacetate + glutamate
AST
AST
RISE
PEAK
RETURN TO NORMAL VALUES
6-8 hours
24 hours
5 days
AST also increase in
in hepatocellular and skeletal muscle dis
hepatocellular= chronic disorder of the liver with progressive damage
Uses malate dehydrogenase and monitors decrease in
absorbance at 340 nm
o Falsely ↑ in hemolyzed sample
Karmen method (AST)
RR of karmen method
5-30 U/L
aminotransferases need co enzyme;
_______ (vitamin B6)
Co-enzyme: this is a type of cofactor that serves as the second substrate for enzyme
when co enzyme is tightly bound it is called: ____ group
pyridoxal phosphate
prostetic
NAD 2 Forms
NAD- Oxidized - Decreased absorbance
NADH- Reduced - Increased absorbance
What Method
Aspartate + a-ketoglutarate
—> ______ —> glutamate + oxaloacetate
Oxaloacetate + NADH + H+—> _____ —>
malate + NAD*
KARMEN METHOD
AST
MD
WHAT IS THE PRODUCT IN KARMEN METHOD
OXALOACETATE/ NAD
Also known as serum glutamic-pyruvic transaminase
(SGPT)
• Transfer of an amino group between alanine and αketoglutarate
• Increased in hepatocellular disorder
Alanine Aminotransferase (ALT
more liver specific
ALT
is used/ sig in the eva of hepatic disorder
-inc in acyte inflammatory disorder of the liver
-used to monitor cause of the hepatitis treatement and effects of drug therapy
-use in screening for post tranfusion hepatitis
-screen for blood donors
ALT
Alanine + a-ketoglutarate
—> _____ —> pyruvate + glutamate
what is the product in this?
ALT
Glutamate
= sensitive test for occupational toxic exposure
ALT
The AST/ALT Ratio
• Differentiates the cause of hepatic disorder
Ratio > 1→
• Ratio < 1 →
DE RITIS RATIO
> 1 Non viral origin
< 1 Viral origin
Uses Lactate Dehydrogenase and monitors decrease in absorbance at 340 nm
ALT / DE RITIS RATIO
Alanine + a-ketoglutarate
—>____ —> pyruvate + glutamate
Pyruvate + NADH + H+
—> ___ —> Lactate + NAD always react with?
ALT
LD
reductase
MAJOR ORGAN AFFECTED IN AST AND ALT
HEART; LIVER
SUBSTRATE IN AST AND ALT
ASPARTIC ALPHA
KETOGLUTARIC ACID;
ALANINE ALPHA
KETOGLUTARIC ACID
END PRODUCTS OF AST and ALT
GLUTAMIC ACID +
OXALOACETIC ACID
GLUTAMIC ACID + PYRUVIC
ACID
COLOR DEVELOPER IN AST AND ALT
2,4 DNPH
2,4 DNPH
COLOR INTENSIFIER OF AST AND ALT
0.4 N NaOH
0.4 N NaOH
METHOD OF AST AND ALT
Reitman and Frankel
Reitman and Frankel
Catalyze the transfer of the γ-glutamyl residue from γglutamyl peptides to amino acids, H20, etc.
Gamma-Glutamyltransferase (GGT)
Used for diagnosis = canaliculi of the hepatic cells specifically the epithelial
cell lining
sensitive marker in ethanol= acute alcoholism
x: hepatobiliary disorder and chronic alcoholism
GGT
COMMON DONOR FOR GGT
GLUTATHIONE
Glutathione + amino acid
—> ___—> glutamyl-peptide
+ L-cysteinylglycine
GGT
The absorbance of p-Nitroaniline is measured
at 405-420 nm
SZAZ ASSAY
wavelength req can be a clue for the possible appearance of product
____ nn = color ed product
< (UV) or > (IR) = colorless product
400-700
400 (UV)
700 (IR)
Y-glutamyl-p-nitroanilide + glycylglycine
—> ___—>
y-Glutamyl-glycylglycine + p-Nitroaniline
GGTP
storage of high energy creatine phosphate
CK
purpose of creating phosphate
high energy reservoir of the body in the muscles
originates in the liver
CK
GMA (glycine, methionine, arginine)
creatine converted to?
creatine phosphate
STRUCTURE OF CK
chimeric dimeric
