glycine metabolism & its clinical significance

Glycine metabolism

Dr Rohini C Sane

Glycine metabolism

1) Non essential amino acids

2) Glucogenic amino acids

FUNCTIONS OF GLYCINE

AMMONIA GLUCOSE

BILE SALTS GLUTATHIONE

CREATINE HEME

DETOXIFICATION OXLATES

SERINE PROTEIN PURINE

GLYCINE

FUCTIONS OF Glycine : ABCDGGHOPPS

Synthesis of Glycine From different biomolecules

Glycine metabolism

1.Synthesis of Glycine from Serine

Synthesis of Glycine from -SerineReversible reaction

Synthesis of Glycine from Threonine

Synthesis of Glycine fromThreonine

Synthesis of Glycinefrom

Glyoxalate

Degradation of Glycine

Degradation of Glycine to Ammonia &CO2

Role of THF in Glycine Metabolism and Ammonia synthesis

Degradation of Glycine to Ammonia &CO2

Role of THF in Glycine Metabolism

Role of Glycine in synthesis of Cysteine

Role of Glycine biosynthesis of molecules

Glycine links many Metabolic pathways & biomolecules

Functions of Glycine: Collagen synthesis1. Collagen –rich in Glycine -30%

Functions of Glycine :Formation of purine ring2.Formation of purine ring : N7

Functions of Glycine -3.Synthesis of Glutathione

Functions of Glycine in Detoxification by conjugation reaction

4.Detoxification by conjugation reaction

• Bile acids cholic acid /cheno cholic acid

• Cholic acid + Glycine Glycocholic acid

• Chenodeoxy cholic acid+ Glycine Glyco- cheno deoxy cholic acid

• Benzoic acid +Glycine Hippuric acid (excreted by kidney )

Functions of Glycine in synthesis of Heme

5.synthesis of Heme

Succinyl CoA + Glycine δ Amino levulinate (ALA )

HEME

ALA SYNTHTASE

Synthesis of Heme from Glycine

Functions of Glycine: Biosynthesis of Creatine

Source of EnergyIn muscles

Excretion in urine

Creatine & creatinine : clinical significance

Creatine Creatinine

Serum 0.2 -0.6 mg/ dl 0.6 -1.0 mg/ dl

Urine 0 – 50 mg/day 1 -2 gm /day

Creatinine estimation–KFT ( CREATININE –ENDOGENOUS ,NOT ABSORBED NOR SECRETED SECRETION,DAILY EXCRETION )

Creatinine coefficient - mg / kg body weight / dayMan - 24-26 mg / kg body weight / dayWoman - 20- 22 mg / kg body weight / day

Creatnuria : muscular dystrophy /Diabetes Mellitus / Hyperthyroidism/ starvation

Arginine ,Glycine & Methionine (SAM)involved insynthesis of Creatine

Metabolic disorders of GlycineGlycinuria

• Serum Glycine concentration is normal/increased in excretion of Glycine in urine ( defective renal reabsorption of Glycine )

• Increased formation of urinary oxlate calculi (stones )

Primary hyperoxaluria

Increased formation of urinary oxlate calculi

↓

oxalosis ( deposition in various tissue )

Generally defective Glycine transaminase

+ impairment in Glyoxalate oxidation to Formate

Vitamin B12 deficiency :Increased formation of urinary oxlate calculi(stones ) corrected by Vitamin B12 supplementation

Glycinuria :Metabolic disorders of Glycine

Role of Glycine in oxalate formation

Primary Oxaluria type Ileads to renal /kidney stone formation & is responsible for mental retardation

Kidney stones ( Calcium oxalate )

Hepatocytes of liver are involved inOxalate synthesis & renal cells are Involved in oxalate excretion

Summary Of Metabolic pathways of Glycine