Study of the reaction of proteins with 3-hydroxy-4-(2-hydroxy-4-sulfo-1-naphthalenyl)azo (Cal-Red) by Rayleigh light scattering technique

Anal Biochem. 2003 Apr 1;315(1):22-8. doi: 10.1016/s0003-2697(02)00694-2.

Abstract

This is the first report on the determination of proteins with 3-hydroxy-4-(2-hydroxy-4-sulfo-1-naphthalenyl)azo (Cal-Red) by Rayleigh light scattering (RLS). At pH 4.07, the weak RLS of Cal-Red can be enhanced greatly by the addition of proteins. On this basis, the reaction of Cal-Red and proteins was studied. A new quantitative determination method for proteins has been developed. This method is very sensitive (0.45-36.9 microgml(-1) for bovine serum albumen (BSA)), rapid (<2min), simple (one step), and tolerant of most interfering substances. The maximum binding number of Cal-Red to BSA was 143 and the binding constant was 4.1x10(6)mol(-1)L. Four samples of total protein in human serum were determined and the maximum relative error is no more than 3%.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acids / chemistry
  • Azo Compounds / chemistry*
  • Binding Sites
  • Humans
  • Hydrogen-Ion Concentration
  • Light
  • Metals / chemistry
  • Models, Chemical
  • Naphthalenes / chemistry*
  • Photochemistry / methods*
  • Proteins / analysis*
  • Scattering, Radiation
  • Sensitivity and Specificity
  • Serum Albumin, Bovine / analysis
  • Sodium Chloride / chemistry
  • Surface-Active Agents / chemistry

Substances

  • 3-hydroxy-4-(2-hydroxy-4-sulfo-1-naphthalenyl)azo
  • Amino Acids
  • Azo Compounds
  • Metals
  • Naphthalenes
  • Proteins
  • Surface-Active Agents
  • Serum Albumin, Bovine
  • Sodium Chloride