(Uncorrected OCR)
Abstract
Porphobilinogen (PBG) synthase condenses two molecules of
aminolaevulinic acid (ALA) to form PBG in heme biosynthesis. The enzyme
activity is sensitive to inhibition by heavy metals such as lead. It can act as a biological indicator of chronic lead POis~r\g to identify the risk group,
especially in children, so that early treatment can be given to prevent possible
permanent damages. A reversed-phase ion-pair HPLC analytical method for
the assay of the PBG synthase activity based on detection of PBG production
has been validated. A Hypersil CN column (150 x 4.6 mm; 5 urn) was
employed together with a mixture of acetonitrile-40 mM phosphate buffer at pH
2.4 with 5 mM 1-heptanesulphonic acid (8:92, v/v). UV detection was
performed at 240 nm. PBG was eluted as a spectrally pure peak resolved from
its impurities in the methanol-inhibited enzyme reaction. The method was
sensitive with a limit of quantitation of 2 ~M. The within-run and between-run
precisions were 8.2% and 13.8% respectively. The recovery was 93.4 �7.1%
(n=6). The preliminary reference range of the PBG synthase activities in the
local pediatric population were from 21.5 to 26.3 ~mol/L RBC/min. Bland and Altman statistical analysis showed that the HPLC assay and the colorimetric assay could not be used interchangeably. The HPLC assay was an alternative way to assess the PBG synthase activities in the human erythrocyte samples.
IV / abstract / toc / Medical Sciences / Master / Master of Medical Sciences
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/30769 |
| Date | January 2004 |
| Creators | Suen, Kin-wah, 孫建華 |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B29624897 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works. |
| Relation | HKU Theses Online (HKUTO) |
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