|
|
||||||||
2ß25(A2)Pro
Ala], an Electrophoretically Silent Variant with Impaired Glycation
1 Department of Clinical Chemistry, University Hospital, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
2
Laboratoire de Spectrometrie de Masse Bio-Organique URA31, CNRS Ecole Europeenne de Chimie Polymeres Materiaux, 67087 Strasbourg, France.
3
Institut für Humangenetik, Westfälische Wilhelms-Universität, D-48149 Münster, Germany.
4
INSERM U473, 94276 Le Kremlin Bicêtre, France.
aAuthor for correspondence. Fax 49-761-270-3444; e-mail bisse{at}med1.ukl.uni-freiburg.de.
Background: Some of the genetic variants of hemoglobin (Hb) and their chemically modified species are known to affect the measurement of Hb A1c. The purpose of this study was to characterize Hb species in the blood sample of a 74-year-old German male with an exceptionally low Hb A1c value.
Methods: Hemolysates from the propositus and a healthy individual were analyzed by electrophoresis, cation-exchange HPLC, boronate affinity chromatography, and electrospray ionization-mass spectrometry (ESMS). Genomic DNA was amplified by PCR, and the sequencing was performed on an ABI 310 sequencer. Functional properties of Hb were determined by oxygen equilibrium studies and CO recombination kinetics after flash photodissociation. Glycohemoglobin species were synthesized by incubating hemolysates with glucose.
Results: A novel, electrophoretically silent ß chain, ß5(A2)Pro
Ala or Hb Görwihl, was detected by cation-exchange HPLC. It accounted for
44% of the total Hb and had functional properties similar to those of normal Hb A and a mild degree of heat instability. During incubation with glucose, glycation of the ß chains (assessed by ESMS) in the hemolysate of a healthy volunteer was twice as fast as in hemolysate from the propositus.
Conclusions: The substitution ß5(A2)Pro
Ala seems to affect neither the functional properties nor the heterotropic interactions of Hb, but slows glycation of the N-terminal valine by an unknown mechanism.
The following articles in journals at HighWire Press have cited this article:
![]() |
E S Kilpatrick Haemoglobin A1c in the diagnosis and monitoring of diabetes mellitus J. Clin. Pathol., September 1, 2008; 61(9): 977 - 982. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. B. Sacks Hemoglobin Variants and Hemoglobin A1c Analysis: Problem Solved? Clin. Chem., August 1, 2003; 49(8): 1245 - 1247. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |