Proteins part 2

• 1. Biuret
  2. Kjeldahl Titration
  3. Folin-Ciocalteau (phenol)
  4. Folin-Lowry
  5. Berthelot
  6. Nessler
  7. Ninhydrin
  8. Refractometry
  9. Dye-Binding
  10. Ultraviolet Absorption


  Analytical Methods of Total Serum Proteins
• • Ambulatory: 6.5 to 8.3 g/dL
  • Recumbent: 6.0 to 7.8 g/dL


  Reference Ranges in Total Serum Protein
• most commonly used method in analysis of serum albumin

  Dye-binding methods
• not affected to some interferences

  Bromcresol green (BCG)
• not subject to most interferences

  Bromcresol purple (BCP)
• 1. Bromcresol green
  2. Bromcresol purple
  3. Methyl orange
  4. 2,4-hydroxy-azobenzene-benzoic acid (HABA)


  Dye Binding Methods
• reference method for analysis of serum albumin

  Immunodiffusion
• In dehydration, values are decreased in total serum protein
• Male: 3.5 to 5.0 g/dL

  Female: ~0.5 g/dL lower


  References Ranges in Serum Albumin
• determination has no clinical utility (infections)

  Salt Fractionation Method

  
  

  Analysis of Serum Globulins
• Globulin= TP-A


  Calculation Method
• Normal albumin : globulin ratio = 1.2-2.3:1
• Globulin is mostly synthesized by liver; B cells (plasma cells)
• • migrates ahead albumin and accounts for CSF proteins (4%)
  • usually not visible in serum protein electrophoresis (SPE)
  • Involve in the transport of thyroid hormones and vitamin A derivatives
  • sensitive marker of poor protein nutritional status (~8 hours half-life)


  Pre-albumin
• • accounts for 53-65% total protein
  • regulator of blood osmotic pressure
  • serves as transport protein for bilirubin, salicylic acid, FA, calcium, magnesium, cortisol

  Albumin
• absence of albumin, and abnormality of genetic origin resulting from autosomal recessive trait

  Analbuminemia
• presence of two albumin bands or an albumin band that is broader than usual

  Bisalbuminemia
• 2.5 to 5% of total protein open (0.1 to 0.3 g/dL)

  Alpha-1-globulin
• • major alpha-1-globulin
  • both an acute phase reactant and protease inhibitor
  • increased when inflammation occurs

  Alpha1-antitrypsin (AAT)
• • Initially synthesized by fetal yolk sac
  • Increased levels in both the amniotic fluid
  • HDFN
  • Trisomy 21 and 18


  Alpha1-fetoprotein (AFP)
• • has very high carbohydrate content
  • transport protein of progesterone and drugs (lidocaine)

  Alpha1-acid glycoprotein - Orosomucoid
• increased in inflammation

  Alpha1-antichymotrypsin (a1-ACT)
• increased in inflammation

  Inter-alpha-trypsin inhibitor (ITI)
• has high binding affinity with Vitamin D

  Gc-globulin
• 7-13% of total protein (0.6 to 1.0 g/dL)

  Alpha-2-globulin
• • one of the largest non-Ig proteins
  • Increased in nephrotic syndrome (10-fold), DM, liver disease, pregnancy, use of contraceptives

  Alpha-2-macroglobulin
• synthesized in the liver and to a small extent of RES

  Haptoglobin
• • copper binding protein
  • decreased in Wilson's disease

  Ceruloplasmin
• 8-14% serum total protein (0.7 to 1.1 g/dL)

  Beta-globulins
• • Primary beta globulin
  • binds and transports iron to ferritin
  • also carries iron to cells that synthesis iron-containing compounds
  • increased in IDA

  Transferrin (siderophilin)
• • removes circulating heme, ferriheme, porphyrins
  • increased in DM, Duchenne-type muscular dystrophy
  • decreased in hemolytic disorders

  Hemopexin
• 1. VLDL
  2. LDL

  Lipoproteins
• • Light chain component of the MHC/HLA
  • found n the surface of most nucleated cells on lymphocytes

  Beta-2-macroglobuin (B2M)
• Collective term for several proteins that participate in the immune reaction

  Complement Proteins
• • forms a fibrin clot when activated by thrombin
  • seen in plasma (not clotted) but NOT in serum (clotted)
  • acute phase reactant

  Fibrinogen
• • appears in blood of patients
  • highly sensitive phase proteins
  • recognized as an independent risk factor in CVD

  C-reactive protein (CRP)
• increased susceptibility of infections and monoclonal gammopathy

  Gamma globulins
• • migrates between beta and gamma peaks
  • protects mucous membranes

  IgA
• • migrates closer to the beta region
  • increased in CMV, rubella, herpes, syphilis, bacterial and fungal
  • Monoclonal increase in Waldenstrom's macroglobulinemia

  IgM
• • Increased in infections, liver disease, connective tissue disorders

  IgD