CC-Lec Amino Acids Part 1

ESSENTIAL AMINO ACIDS

● Phenylalanine

● Valine

● Threonine

● Tryptophan

● Isoleucine

● Methionine

● Histidine

● Arginine

● Leucine

● Lysine

NONESSENTIAL AMINO ACIDS

● Alanine

● Asparagine

● Aspartic Acid

● Cysteine

● Glutamic Acid

● Glutamine

● Glycine

● Proline

● Serine

● Tyrosine

autosomal recessive trait

PHENYLKETONURIA (PKU)

PHENYLKETONURIA (PKU) is the Total absence or activity of?

PHENYLALANINE HYDROXYLASE

Catalyzes the conversion of phenylalanine to tyrosine

PHENYLALANINE HYDROXYLASE

COMPLICATIONS of PKU on Children?

Occurs as a result of the toxic effects of the brain of phenylpyruvate or one of its metabolic by-products

Retarded mental development

Retarded mental development on children happends on what duration?

2nd or 3rd week of life

deamination of phenylalanine

Phenylpyruvate

decarboxylation and oxidation of phenylpyruvate

Phenylacetic acid

glutamine conjugate of phenylacetate

Phenylacetylglutamine

What are the METHODS OF DETERMINATION for PKU?

Guthrie Bacterial Inhibition Assay

Microfluorometric assay

High-Performance Liquid Chromatography (HPLC)

Urine Test

Spores of Bacillus subtilis are incorporated into an agar plate that contains beta-2- thienylalanine (antagonist)

Guthrie Bacterial Inhibition Assay

Filter paper disk impregnated with blood from the infant is placed on the agar

Guthrie Bacterial Inhibition Assay

If blood phenylalanine is 3-4 mg/dL or more, phenylalanine counteracts the antagonist and bacterial growth occurs

Guthrie Bacterial Inhibition Assay

direct measurement of phenylalanine in dried blood filter disks

Microfluorometric assay

Based on the fluorescence of a complex formed of phenylalanine-ninhydrin-copper in the presence of a dipeptide (Lleucyl-L-alanine)

Microfluorometric assay

Excitation/emission wavelengths of 360 nm and 530 nm respectively

Microfluorometric assay

Positive blood tests in PKU will produce what?

Bacterial Halo

Positive control in PKU?

increasing phenylalanine concentrations give bacterial halos

Reference method for PKU?

High-Performance Liquid Chromatography (HPLC)

How much sample is needed for HPLC when it comes to Newborns?

Newborn: 1.2 – 3.4 mg/dL (70-200 umol/L)

A test for PKU used for monitoring/ reagent strip test?

Urine Test

Involves the reaction of ferric chloride with phenylpyruvic acid in urine to produce a green color

Reagent strip test

Characterized by excretion of tyrosine and tyrosine catabolites in urine

TYROSINEMIA

TYROSINEMIA has Deficiency in? Enumerate the Types.

– Fumarylacetoacetate (FAA) hydrolase (type I)

– tyrosine aminotransferase (type II)

– 4-hydroxy-phenylpyruvic acid oxidase (type III)

COMPLICATIONS of this disease:

Leads to liver damage (Cirrhosis and liver cancer)

TYROSINEMIA

Familial inheritance

ALKAPTONURIA

ALKAPTONURIA is a lack of what enzyme?

homogentisate oxidase

accumulates in connective tissue causing generalized pigmentation of these tissues (Ochronosis), an arthritis-like degeneration

ALKAPTONURIA

Characterized by darkening of urine

ALKAPTONURIA

Characterized by burnt sugar odor of the urine, breath, and skin

MAPLE SYRUP URINE DISEASE

Lack of branched-chain alpha-ketoacid decarboxylase which blocks the normal metabolism of: Leu, Ile and Val

MAPLE SYRUP URINE DISEASE