One-step immunoassay for tetrabromobisphenol a using a camelid single domain antibody-alkaline phosphatase fusion protein

Details

• Personal Author:
  Bever CRS ; Gee SJ ; Hammock BD ; Li J ; Majkova Z ; Wang J ; Xu T ; Yang J
• Description:
  Tetrabromobisphenol A (TBBPA) is a ubiquitous brominated flame retardant, showing widespread environmental and human exposures. A variable domain of the heavy chain antibody (VHH), naturally occurring in camelids, approaches the lower size limit of functional antigen-binding entities. The ease of genetic manipulation makes such VHHs a superior choice to use as an immunoreagent. In this study, a highly selective anti-TBBPA VHH T3-15 fused with alkaline phosphatase (AP) from E. coli was expressed, showing both an integrated TBBPA-binding capacity and enzymatic activity. A one-step immunoassay based on the fusion protein T3-15-AP was developed for TBBPA in 5% dimethyl sulfoxide (DMSO)/phosphate buffered saline (PBS, pH 7.4), with a half-maximum signal inhibition concentration (IC50) of 0.20 ng mL(-1). Compared to the parental VHH T3-15, T3-15-AP was able to bind to a wider variety of coating antigens and the assay sensitivity was slightly improved. Cross-reactivity of T3-15-AP with a set of important brominated analogues was negligible (<0.1%). Although T3-15-AP was susceptible to extreme heat (90 degrees C), much higher binding stability at ambient temperature was observed in the T3-15-AP-based assay for at least 70 days. A simple pretreatment method of diluting urine samples with DMSO was developed for a one-step assay. The recoveries of TBBPA from urine samples via this one-step assay ranged from 96.7% to 109.9% and correlated well with a high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS) method. It is expected that the dimerized fusion protein, VHH-AP, will show promising applications in human exposure and environmental monitoring. [Description provided by NIOSH]
• Subjects:
  Biomarkers Chemistry Chemistry, Analytic Fires Immune System Occupational Health Safety
• Keywords:
  Analytical-chemistry Analytical-processes Fire-retardants Immunoassays Immunology Polybrominated-biphenyls
• ISSN:
  0003-2700
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Journal Article
• Place as Subject:
  California ; Idaho ; OSHA Region 10 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  87
• Issue:
  9
• NIOSHTIC Number:
  nn:20047159
• Citation:
  Anal Chem 2015 May; 87(9):4741-4748
• CAS Registry Number:
  Phenol, 4,4′-(1-methylethylidene)bis-, tetrabromo deriv. (CAS RN 121839-52-9)
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  University of California - Davis
• Peer Reviewed:
  True
• Start Date:
  20010930
• Source Full Name:
  Analytical Chemistry
• End Date:
  20270929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:559a49d24b51f858ca7458dc4884fab47af77d6a0040ab4ca89ff2f99770316879267518437e2f75c18324c35c971fa09087bbb6e49b2827f8bd1c414fda990c
• Download URL:
  https://stacks.cdc.gov/view/cdc/202329/cdc_202329_DS1.pdf
• File Type:
  [PDF - 447.08 KB ]