Amino Acids and Proteins Flashcards
Plasma proteins are the most commonly analyzed proteins and can be divided into 2 major groups:
Albumin
Globulins
It migrates before albumin in classic serum protein electrophoresis (SPE)
Prealbumin or transthyretin
It is a transport protein for the thyroid hormones, thyroxine, and triiodothyronine.
Prealbumin or transthyretin
Prealbumin has a half-life of approximately ___.
2 days
It is synthesized in the liver at the rate of 9 to 12 g/day and it is the most abundant protein in the plasma.
Albumin
Albumin is a _____ acute pjase reactant
Negative
Primary function of albumin is?
Its capacity to bind and transport various substances in the blood.
Represents trends in blood glucose over a period of 3 months or approximately 120 days.
Glycated Hemoglobin
The primary site for protein synthesis is?
Liver
Absence of albumin in known as
Analbuminemia
Presence of albumin that has unusual molecular characteristics is referred to as?
Demonsrrated by the presence of two albumin bands instead of a single one during electrophoresis
Bisalbuminemia
- a glycoprotein synthesized in the liver.
- its main function is in the inhobition of the protease, neutrophil elastase.
- positive acute-phase reactant
a1-antitrypsin
Mutations in the ______ gene can lead to a deficiency of a1-antitrypsin protein or an abnormal form of the protein that does not properly control neutrophil elastase
SERPINA1 gene
Quantitative methods used to confirm a1-antitrypsin deficiency are (2)
Radial immunodiffusion
Automated immunonephelometric assays
- is synthesized in utero by the developing embryo and fetus and then by the parenchymal cells of the liver.
- it protects the developing fetus from immunologic attack by the mother.
- reaches adult concentration at 8-12 months.
a1-Fetoprotein (AFP)
AFP screening is performed between ___ and _____ weeks of gestations when maternal AFP gradually increases; therefore,interpretation requires accurate dating of pregnancy.
15-20 weeks
The methods commonly used in AFP determination is (2)
Radioimmunoassay (RIA)
Enzyme-labeled Immunoassay (EIA)
AFP may also be used as a tumor marker and is fractionated by affinity electrophoresis into three isoforms (L1, L2, and L3) based on their reactivity with the lectin _______.
Lens culinaris agglutinin (LCA)
It is now being considered as a tumor marker for the North American population for screening chronic liver disease patients for hepatocellular carcinoma (HCC)
AFP-L3
- is a major plasma glycoprotein that is negatively charged even in acidic solutions lending to its name.
- produced by the liver and is a positive acute-phase reactant.
- serum _____ concentrations are also used in the diagnosis and evaluation of neonatal bacterial infections.
a1-Acid glycoprotein (AAG) or orosomucoid
The analytic methods used most commonly for the determination of AAG are (3)
Radial immunodiffusion
Immunoturbidity
Nephelometry
- is an a-globulin glycoprotein that is a member of the serine proteinase inhibitor (serpin) family.
- it inhibits the activity of the enzymes cathepsin G, pancreatic elastase, mast cell chymase, and chymotrypsin by cleaving them into a different shape (conformation).
- produced in the liver and is a positive acute-phase reactant that increases during inflammation.
a1-Antichymotrypsin
- are a family of serine protease inhibitor l, assembled from two precursor proteins: a light chan and one or two heavy chains.
- have been shown to play a particular role in inflammation and carinogenesis.
Inter-a-Trypsin inhibitor
- is also known as a group-specific component or vitamin D-binding protein.
- synthesized by the hepatocytes and is the mahor carrier protein for vitamin D and its metabolites.
- it also transports components such as fatty acids and endotoxins.
Gc-globulin
- The resulting decrease in ____ concentration makes it usable as a prognostic indicator of survival of patients with significant tissue injury after trauma and among patients with hepatic failure.
-it may be of importance for bone formation and in the immune system.
Gc-Globulin
What is the method of choice for Gc measurements?
Immunonephelometry
- it is an a2-glycprotein synthesized in the liver and is a tetramer consisting of two a and two b chains.
- its primary function is to bind free hemoglobin to prevent the loss of its constituent, iron, into the urine.
- it is a positive acute-phase reactant that increases in many inflammatory diseases, such as ulcerative colitis, acute rheumatic disease, acute myocardial infarction, and severe infection.
Haptoglobin
Quantitative determination for haptoglobin (2)
Radial immunodiffusion
Immunonephelometric methods
- is a copper-containing, a2-glycoprotein enzyme that is synthesized in the liver.
- it is a positive acute-phase reactant and is frequently elevated in inflammation, severe infection, and tissue damage and may be increased with some cancers.
Ceruloplasmin
Ceruloplasmin is primarily measured along with blood and urine copper test to aid in the diagnosis of?
Wilson’s disease
The analytic method of ceruloplasmin determination was based on its _______ activity. Most assays today use immunochemical methods including (2)
Copper oxidase activity
Radial immunodiffusion
Nephelometry
- is a tetramer of four identical subunits that is synthesized by the liver and is a major component of the a2-band in protein electrophoresis.
a2-Macroglobulin
Analytic methods used for measurement of a2-macroglobulin are (4)
Radial immunodiffusion
Immunonephelometry
Enzyme-linked immunosorbent assay (ELISA)
Latex agglutination immunoassay
- is a negative acute-phase glycoprotein synthesized by the liver.
- it is a major component of b-globulin fraction on protein electrophoresis and plays an important role in the transport of iron.
- it also carries iron to other sites, such as the bone marrow, that synthesize hemoglobin and other iron-containing compounds.
Transferrin or siderophilin
____ prevents iron from being inappropriately deposited in tissues during temporary increases in absorbed iron or free iron.
Transferrin
An increase of iron bound to transferrin is found in hereditary disorder of iron metabolism, known as ______ in which excess iron is deposited in the tissue, especially in the liver and the pancreas l.
hemochromatosis
It is inherited as an autosomal recessive trait due to mutation of both transferrin genes, with a resulting absence of transferrin.
Atransferrinemia
Analytic methods used for the quantitation of transferrin (2)
Immunodiffusion
Immunonephelometry
Total serum iron is low, but TIBC is increased, and transferrin saturation becomes very low.
Iron deficiency
Total serum iron is high and TIBC is low or normal, causing transferrin saturation to increase.
Iron overload
- the parenchymal cells of the liver synthesize ____, which migrates electropheretically in the b-globulin region and is an acute-phase reactant.
- its main function is to bind with free heme.
Hemopexin
Heme-hemopexin complex is carried to the liver and has a ration of?
1:1
Hemopexin determinations are performed by?
Radial immunodiffusion
Are complexes of proteins and lipids whose function is to transport cholesterol, triglycerides, and phospholipids in the bloodstream.
Lipoproteins