Proteins Flashcards
Contain peptide chains on hydrolysis yield only amino acids. (Classification of Proteins)
Simple Proteins
Proteins are synthesized in the liver and secreted by hepatocytes into circulation except:
Immunoglobulins
*secreted by plasma cells
Comprise of a protein and a non-protein moeity/ prosthetic grp. (Classification of Proteins)
Conjugated proteins
Also known as transthyretin.
Half-life of 2 days.
Used as landmark to confirm if specimen is really CSF.
Prealbumin
*rich in tryptophan, contain 0.5% carbohydrate
Prealbumin
Increased in:
Decreased in:
Increased:
Alcoholism
Chronic Renal Failure
Steroid treatment
Decreased:
POOR NUTRITION
Why is it in Cirrhosis we find patients with normal Total Protein?
Increased Globin, decreased albumin
Makes total protein NORMAL.
A1-anti-trypsin deficiency is seen in:
Emphysema
Juvenile hepatic cirrhosis
Increased in:
Inflamation
Pregnancy
Contraceptive use
A glycoprotein that migrates between albumin and a-1 globulin band.
Alpha-feto protein
- AFP screening is done between 15-20 weeks of gestational age when the maternal level increases gradually.
Decreased levels of alpha-feto protein.
Down’s syndrome
*increased in: Hepatoma >1000ng/ml Spina bifida Nueral tube defects GIT atresia Ataxia telangiectasia Tyrosinosis HDN Anencephaly
Protein that contains high percentage of CHO and sialic acid ( 45% and 11-12% respectively)
Also known as OROSMUCOID.
a1-Acid Glycoprotein
*greatest affinity for PROGESTERONE; binds with quinidine
Protein / serine protease with CATHEPSIN G.
Migrates between the a1 and a2 zones
a1-Antichymotrypsin
- binds and inactivates PSA (prostate specific Antigen)
- seen in Alzheimer’s disease
Binds heme released by degradation of hemoglobin; has the strongest affinity with heme.
Helps in the diagnosis of EARLY HEMOLYSIS
Hemopexin
*migrates in the Beta region
Protein that exhibits affinity with vitamin D and Actin.
Group-specific component (Gc)-Globulin
*migrates between a1 and a2
Indicator of Wilson’s disease. (Decreased)
Ceruloplasmin
*features of Wilson’s disease:
Deposition of copper in the skin, brain and cornea (Kayser-Fleisher ring)
Largest major non-immunoglobulin protein in plasma.
a2-Macroglobulin /AMG
*increase 10x in nephrosis
Light chain component of the major human leukocyte antigen.
Found on ths surface of most nucleated cells.
Needed in the production of CD8 cells.
B2-Microglobulin
Increased in: Renal Failure Multiple Myeloma RA SLE HIV
Also known as SIDEROPHILIN.
Major component of the b2-globulin fraction.
Transferrin
- also a negative acute phase reactant LIKE ALBUMIN
- elevated levels appear as “paraprotein”
A member of pentraxin protein family.
Gamma-migrating protein.
C-reactive protein.
Highly specific for AMI.
Troponin I
Overload proteinuria includes conditions:
Hemoglobinuria
Myoglobinuria
Bence-Jones proteinuria
Most common and serious type of abnormal proteinuria.
Often called as albuminuria.
Glomerular proteinuria
Is an early indicator of glomerular dysfunction.
Microalbuminuria
An ultra-filtrate of plasma formed in the choroid plexus of the ventricles of the brain.
CSF
Is the presence in CSF of 2 or more IgG bands in the gamma region.
Seen in MULTIPLE SCLEROSIS.
CSF OlIgoclonal banding.
An inborn error of metabolism characterized by the absence of homogentisate oxidase in tyrosine pathway.
Alkaptonuria
*clinical feature: OCHRONOSIS/ Tissue pigmentation
Screening test for Homocystinuria.
Modified Guthrie Test
*L-methionine sulfoximine antagonist.
- also for MSUD –> 4-azaleucine antagonist
- reduced or absence of cystathionine B-synthetase
Characterized by the absence of a-ketoacid decarboxylase.
MSUD
*leucine isoleucine valine LIV increased!!!
Autosomal recessive disorder deficient of phenylalanine hydrolase, phenylalanine-4-mono-oxygenase.
Phenylketonuria
*deficiency of tetrahydrobiopterin /BH4 also cause elevated blood levels of phenylalanine
