Protein Flashcards
Proteins differ from carbs and lipids how? (3)
- Contain nitrogen
- Must be continually synthesized (most synthesized in liver, also in plasma cells/bone marrow)
- Not stored for emergency use
What 4 hormones control protein SYNTHESIS?
- Growth Hormone 2. Insulin 3. Testosterone 4. Thyroxine
What 2 hormones control protein CATABOLISM?
- Cortisol 2. Glucagon
Nitrogen Balance. Negative and Positive causes:
Neg: excessive tissue destruction (burns), wasting disease, continual high fever, starvation.
Pos: periods of growth, pregnancy, repair processes
Total Serum Protein: TSP
albumin and globulin
Globulins = a-1-globulin, a-2-globulin, B-globulin, and y-globulin proteins
How do yo separate proteins?
Electrophroresis: technique separates proteins based on charge.
Clinical Application of Electrophoresis. What samples will you use this for?
serum, urine, CSF
Total Serum Protein (TSP) Function
Transport small molecules, receptors, catalyze biochemical rxns, structural, nutritional source, oncotic pressure, defense against foreign antigen, hormones, aids in maintenance of homeostasis, maintenance of acid-base balance
Total Serum Protein (TSP) Factors that affect it
malnutrition, hepatic function with dec. syntesis, renal functinon w/ inc. urinary loss, metabolic disorders and enzyme defects, GI function with dec. absorption or inc. loss, disease causing cellular proliferation, inc. synthesis, dehydration
Lab Measurement TSP specimens
Fasting serum: specimen of choice
Total urine protein, CSF protein, Body fluid protein.
Recommended to take concurrent samples for comparison.
Math equation to calculate globulins
TSP - albumin = globulins
Screening for Disorders, you can use 2 tests
TSP and albumin are a componenet of routine screening pannels (chem profile, metabolic, hepatic function, renal function) Protein Electrophoresis (abnormal result warrants further follow up)
Acute Phase Reactants: Which are Positive (+APR) and Negative (-APR)?
Pos: Alpha-1antitrypsin (AAT), Hepatoglobin (HPT), Ceruloplasmin (CER), Fibrinogen (FBG), *C-reactive protein (CRP)
Neg: *Albumin (ALB), Pre-albumin (PALB), Transferrin (TRF)
Pre-albumin (PALB)
- Sensitive marker of nutritional status
- Transports thyroid hormone and retinol
- Routine clinical methods are not sensitive to visualize on SPE (Serum protein electrophoresis)
Decreased PALB (Prealbumin)
- Liver disease (dec synthesis)
- Malnutrition, anorexia, malabsorption
(-APR) Acute phase reactants
Albumin (ALB)
- Most predominant protein of TSP
- Functions to maintain oncotic pressure of plasma
- Predominant protein lost in renal disease
- Transports less soluble compounds
- Synthesized in liver
Decreased ALB (Albumin)
Liver disease, renal disease (NS), GI loss, (-APR)
Increased ALB (Albumin)
Dehydration
Alpha-1-antitrypsin (AAT)
Majority of alpha-1-globulins
Neutralizes trypsin-like enzymes
Phenotype MM
Decreased AAT (Alpha-1-antitrypsin)
Severe pulmonary disease, liver disease, juvenile hepatic cirrhosis
Increased AAT (Alpha-1-antitrypsin)
(+APR)
Aplha-2-macroglobulin (AMG)
HUGE protein: unable to pass glomerulus
Inhibits protease, inhibits thrombin
Increased AMG (Alpha-2-macroglobulin)
Nephrotic Syndrome (Up to 10x, maintains oncotic pressure in absence of albumin)
Haptoglobin (HPT)
-Binds free hemoglobin
Decreased Haptoglobin (HPT)
Hemolytic anemia
Increased Haptoglobin (HPT)
(+APR)
Ceruloplasmin (CER)
Contains >90% copper
Decreased Ceruloplasmin (CER)
Associated w/ Wilson’s disease (dec serum copper, inc urine copper)
Liver Disease
Increased Ceruloplasmin (CER)
(+APR)
Transferrin (TRF)
Major component of beta-globulins
Transports iron in plasma
Decreased Transferrin (TRF)
Liver disease, renal disease, (-APR)
Increased Transferrin (TRF)
Iron Deficiency Anemia (IDA)
Beta-lipoprotein (LDL)
"Bad cholesterol" Transports lipids (esp. cholesterol) through plasma
Increased Beta-lipoprotein (LDL)
Nephrotic syndrome, Increased risk of CHD
Complement C3 Component
- Components of beta globulins
- Participates in immune response contributing to cell lysis
Decreased Complement C3 Component
Recurrent infections
C-Reactive Protein (CRP)
Most sensitive of the APRs: levels rise within 24-48 hrs.
Serial measurements helpful
Increased C-Reactive Protein (CRP)
Inflammatory response
Cardiac risk assessment (need ‘high sensitivity’ method)
Imunoglobulins (Ig)
- Gamma globulins
- Antibodies: heavy chain, light chain
- Produced by plasma cells (B-cells) in bone marrow
Decreased Immunoglobulins (Ig)
“hypogammaglobulinemia”:
Congenital, genetic (Selective IgA, Bruton’s)
Acquired (NS, AIDS)
Increased Immunoglobulins (Ig)
“hypergammaglobulinemia”:
- Polyclonal increase: response to infecion
- Monoclonal increase: unrestrained proliferation (multiple myeloma, waldenstrom’s macroglobulinemia)
Increased Urine Protein
- Increased glomerular permeability (NS, renal disease)
- Multiple Myeloma (paraprotein)
- Intravascular hemolysis (hemoglobin)
- Tubular failure (drugs, toxins)
CSF Protein
Proteins in CSF from plasma, Normal pattern similar to SPE but in lower conc., Concurrent serum
CSF Protein Clinically measured why?
Assess integrity of blood brain barrier
Aid in diagnosis of disease
Increased CSF Protein
Meningitis, Multiple Sclerosis
