Characterization of Methylene Diphenyl Diisocyanate Haptenated Human Serum Albumin and Hemoglobin

Details

• Personal Author:
  Chipinda I ; Hettick JM ; Mhike M ; Siegel, Paul D. ; Simoyi R
• Description:
  Methylene diphenyl diisocyanate (MDI) is widely used as an intermediate in the manufacture of polyurethane foam, elastomers, paints and a variety of other products. Protein adduct formation (i.e. haptenation) by MDI is considered a necessary step leading to immunological sensitization and asthma. MDI haptenated human serum albumin (MDI-HSA) is used to measure specific antibody in workers, but these haptens are poorly characterized. The objective of the present study was to evaluate Hemoglobin (Hb) and HSA following conjugation to different molar ratios of MDI: protein (1:1, 5:1, 10:1, 40:1). MDI-protein conjugates were digested by acid hydrolysis (pH 1) at 100 degrees C for 16 hours to hydrolyze/cleave the MDI from the protein to obtain free methylene dianiline (MDA). MDA was extracted, derivatized with fluorescamine and assayed by high performance liquid chromatography with fluorescence detection. Haptenated proteins were also digested with trypsin and specific amino acid conjugation sites determined by ultra-performance liquid chromatography-quadruple-tandem time-of-flight mass spectrometry (UPLC-qTOF MS/MS). The trinitrobenzene sulfonic acid assay was used to determine the extent of crosslinking in MDI-HSA. In both proteins, MDI conjugation was observed to be concentration dependent. Greater binding to HSA than Hb was observed by measurement of the MDI hydrolysis product. Mass spectrometry identified only eight binding sites for Hb compared to twenty for HSA (at 40:1 molar ratio of MDI: protein). Self-polymerization of MDI onto protein was observed on some amino acids at higher MDI concentrations. The TNBS assay was used to confirm cross linking in MDI-HSA with approximately 60% loss of amine reactivity at the highest binding ratio. It is concluded that MDI has a greater reactivity toward HSA than Hb with respect to the number of residues haptenated and amount of MDI bound per mole of protein. [Description provided by NIOSH]
• Subjects:
  Chemistry Hypersensitivity Isocyanates Occupational Health Safety
• Keywords:
  4,4'methylenebisphenyl Isocyanate Amino Acids Chemical Reactions Diisocyanates MDI Polyurethane Foams Sensitization
• Publisher:
  Work Wellness and Disability Prevention Institute (WWDPI)
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; Oregon ; OSHA Region 10 ; OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  73
• NIOSHTIC Number:
  nn:20054302
• Citation:
  Isocyanates & Health: Past, Present and Future, April 3-4, 2013, Potomac, Maryland. Vancouver, BC, Canada: Work Wellness and Disability Prevention Institute (WWDPI), 2013 Apr; :73
• Contact Point Address:
  Mr. Morgan Mhike, Regular Fellow, National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, Morgantown, WV 26505
• Email:
  vqn3@cdc.gov
• CAS Registry Number:
  4,4'-Diaminodiphenylmethane (CAS RN 101-77-9) ; Diphenylmethane diisocyanate (CAS RN 101-68-8)
• Federal Fiscal Year:
  2013
• Peer Reviewed:
  False
• Source Full Name:
  Isocyanates & Health: Past, Present and Future, April 3-4, 2013, Potomac, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c7c65b41e4e337120482e26a5686579ee5f3b0a72b6df644a07252fba8ba57db1765102f5c6561f07d8c96a3b747ab9a6fef4711464c42581edecf97d5b99672
• Download URL:
  https://stacks.cdc.gov/view/cdc/216894/cdc_216894_DS1.pdf
• File Type:
  [PDF - 703.98 KB ]