AMINO ACIDS AND AMINOACIDOPATHIES Flashcards
Amino acids are linked together by
peptide bonds/amide linkage.
Formation is through dehydration synthesis/condensation.
Amino acids
Interaction between COOH of one molecule reacts with the NH2 of the other molecule, releasing H2O forming amide.
Amino acids
make amino acids differ from one another.
R- chains
dietary source (not produced by the body)
Essential amino acids-
produced by the body.
Non-essential amino acids-
11 non-essential AA
C A4 G3 PST
Alanine
Arginine
Asparagine
Aspartic Acid
Cysteine
Glutamic Acid
Glutamine
Glycine
Proline
Serine
Tyrosine
Essential AA
HILL MP T2V
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
21st AA named in 2002
Encoded in UGA (stop codon)
Selenocysteine (Sec)
Selenium analogue of cysteine and found in enzymes formate dehydrogenases, glycine reductases and some hydrogenases.
Low level is found in HIV infected.
Selenocysteine (Sec)
22nd AA (2002) not present in human.
Pyrrolysine (Pyl)
Found in bacteria and archaea specifically the enzymes for methane-producing metabolism.
Encoded by the UAG (stop codon)
Pyrrolysine (Pyl)
Inherited errors of metabolism due genetic mutation.
Aminoacidopathies
Excessive amino acids result to toxicity to
brain, blood and tissues.
used for early diagnosis and management. Confirmatory are mass spectrometry and molecular technique.
Newborn screening tests (NBS)
What are the Aminoacidopathies
Phenylketonuria
Tyrosinemia
Alkaptonuria
Maple Syrup Urine Disease
Isovaleric Acidemia
Homocystinuria
Citrullinemia
Argininosuccinic Aciduria
Cystinuria
Mutations in the PAH gene that result to defect in phenylalanine hydroxylase (PAH) enzyme reduction.
Phenylketonuria (PKU)
PAH catalyzes the conversion of phenylalanine to ____.
tyrosine
PAH gene defect
Phenylalanine Hydrolase
excreted in the urine giving characteristic “musty” or “mousy” odor.
Phenylketonuria (PKU)
Phenylketonuria (PKU) Screening test
Guthrie test
Inhibitor of Guthrie test
B-2-thienylalanine
Types of Tyrosinemia gene mutation and defect in
Type 1
Type 2
Type 3
FAH - Fumarylacetoacetate hydrolase
TAT - Tyrosine aminotransferase
HPD - 4-hydroxyphenylpyruvate dioxygenase
Alkaptonuria gene mutation lead to the deficiency of ?
Homogentisate oxidase
In the urine it produces brownish-black color when exposed in the air.
Alkaptonuria
Alkaptonuria
screening test
Ferric Chloride Test (turns balck when positive)
MSUD gene mutation lead to absence or low
BCKDHA
BCKDHB
DBT
MSUD enzyme
Branched-chain-a-ketoacid decarboxylase
BCKD enzymes are responsible for ___, _____, and _____ metabolism. These are branched chain amino acids.
leucine, isoleucine, and valine
In the urine it gives characteristic “maple syrup” or “burnt sugar” odor.
Maple syrup urine disease (MSUD)
Maple syrup urine disease (MSUD)
screening test
Modified Guthrie test (4-azaleucine used as inhibitor)
IVD gene mutation result to deficiency in isovaleryl-CoA dehydrogenase (IVD) which metabolize of leucine.
Isovaleric acidemia (IVA)
Sweaty feet odor of urine is distinctive characteristic.
Isovaleric acidemia (IVA)
Isovaleric acidemia (IVA) gene mutation
Isovaleryl-CoA dehydrogenase
CBS gene mutation (most common) result to deficiency in cystathionine β synthase responsible for methionine metabolism.
Homocystinuria
Elevated concentration of methionine and homocysteine (precursor) in blood and urine.
Homocystinuria
Homocystinuria
Screening test:
Modified Guthrie Test (L-methionine sulfoximine used as inhibitor)
Homocystinuria gene mutation
Cystathionine B synthase
Urea Cycle disorders
Citrullinemia
Citrullinemia Types
Type I
Type II
ASS1 gene mutation (argininosuccinic acid synthetase deficiency)
SLC25A13 gene mutation (Citrin deficiency)
Argininosuccinic Aciduria
gene mutation
Argininosuccinic acid lyase
Elevated level of ammonia in the blood.
Argininosuccinic Aciduria
SLC3A1 and SLC7A9 genes mutation codes for the production of protein the kidney responsible for reabsorption of cystine.
Cystinuria
