Assay of hemoglobin A1c using lectin from Aleuria aurantia.

Masato Kabata,Yasushi Ueno,Erina Hase,Yuka Kobayashi,Kazuaki Yoshimune,Kouta Kimura

doi:10.1186/s13568-016-0288-7

Masato Kabata, Yasushi Ueno + Show 4 more

Open Access

https://doi.org/10.1186/s13568-016-0288-7

Copy DOI

Abstract

Hemoglobin A1c (HbA1c) has an N-terminal fructosyl valine on the β-chain, and this modification is caused by the non-enzymatic glycosylation of hemoglobin (Hb). The relative concentration ratio of HbA1c to total Hb is an important biomarker for the diagnosis of diabetes. HbA1c-binding lectins were screened from 29 sources of lectin, and the lectin from Aleuria aurantia (AAL) was revealed to have higher affinity to HbA1c than to Hb. The concentration of HbA1c was determined by lectin-based enzyme-linked immunosorbent assay (ELISA) using the AAL lectin. Higher reproducibility of the assay was observed at 4 °C than at 25 and 37 °C. This observation is consistent with the known temperature-dependent behavior of lectins. Preincubation of HbA1c with an anti-HbA1c antibody inhibited the binding, suggesting that AAL binds to the N-terminal fructosyl valine epitope of HbA1c. Higher inhibitory effect was observed for 10 mM d-fructose than for the same concentrations of l-fucose, d-fucose, or d-glucose.

Highlights

The number of people with diabetes is increasing globally, especially in developing countries, with over 346 million people diagnosed worldwide (Little and Rohlfing 2013)
Screening of hemoglobin A1c (HbA1c)‐binding lectins HbA1c-binding lectins were screened from 30 sources using lectin-based enzyme-linked immunosorbent assay (ELISA), as described in the “Materials and methods” section
lectin from Aleuria aurantia (AAL) was selected for further experiments as it was found to bind with HbA1c, but not with Hb

Summary

Introduction

The number of people with diabetes is increasing globally, especially in developing countries, with over 346 million people diagnosed worldwide (Little and Rohlfing 2013). The major hallmark of diabetes is high glucose levels in the blood. The concentration of glucose in the blood is not reliable for the diagnosis of diabetes because of fluctuations in these concentrations throughout the day. The relative concentration ratio of hemoglobin A1c (HbA1c) to hemoglobin (Hb) is a reliable biomarker for the diagnosis and prognosis of diabetes (Little and Rohlfing 2013). HbA1c is produced by a non-enzymatic reaction between glucose (McDonald et al 1978) and the N-terminal valine of the β-chain of hemoglobin in red blood cells. Since the half-life of red blood cells is approximately 2 months, the concentration of

Methods

Results

Conclusion