Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard
LP[a] is one of the most atherogenic lipoproteins consisting of an LDL-like core particle and a covalently linked glycoprotein of variable size. Due to its structural features, its heterogeneity and instability, there are great difficulties in standardizing quantitative immunochemical Lp[a] assays....
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doaj-7ba6beb75438478fa678c65ad680e0392021-04-27T11:49:22ZengElsevierJournal of Lipid Research0022-22751999-12-01401222552263Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standardGert M. Kostner0Anton Ibovnik1Herwig Holzer2Harald Grillhofer3To whom correspondence should be addressed.; Institute of Medical Biochemistry, University of Graz, Harrachgasse 21, 8010 Graz, AustriaInstitute of Medical Biochemistry, University of Graz, Harrachgasse 21, 8010 Graz, AustriaDepartment of Nephrology and Hemodialyses, Auenbruggerplatz 15, 8036 Graz, AustriaInstitute of Medical Biochemistry, University of Graz, Harrachgasse 21, 8010 Graz, AustriaLP[a] is one of the most atherogenic lipoproteins consisting of an LDL-like core particle and a covalently linked glycoprotein of variable size. Due to its structural features, its heterogeneity and instability, there are great difficulties in standardizing quantitative immunochemical Lp[a] assays. One particular problem is the preparation of a pure primary standard, which is sufficiently stable to be used for value assignment of secondary reference material. Here we describe a method to purify Lp[a] to virtual homogeneity. When mixed with glycerol at a ratio of 1:1, the preparation is stable in the deep frozen state for more than 12 months. This latter material gave dose–response curves in several immunochemical assays that were parallel to fresh or frozen sera, freshly prepared Lp[a], and other proposed reference materials. After determination of the protein content by amino acid analysis, it was possible to assign concentrations in molar and mass units to these preparations considering the theoretical molecular weights of the particular apo[a] isoform. Thus we propose to use this procedure for preparation of a “gold standard” for Lp[a] assays.—Kostner, G. M., A. Ibovnik, H. Holzer, and H. Grillhofer. Preparation of a stable fresh frozen primary lipoprotein[a] (LP[a]) standard.http://www.sciencedirect.com/science/article/pii/S0022227520321003DELFIALDLELISAglycerol |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Gert M. Kostner Anton Ibovnik Herwig Holzer Harald Grillhofer |
spellingShingle |
Gert M. Kostner Anton Ibovnik Herwig Holzer Harald Grillhofer Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard Journal of Lipid Research DELFIA LDL ELISA glycerol |
author_facet |
Gert M. Kostner Anton Ibovnik Herwig Holzer Harald Grillhofer |
author_sort |
Gert M. Kostner |
title |
Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard |
title_short |
Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard |
title_full |
Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard |
title_fullStr |
Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard |
title_full_unstemmed |
Preparation of a stable fresh frozen primary lipoprotein[a] (Lp[a]) standard |
title_sort |
preparation of a stable fresh frozen primary lipoprotein[a] (lp[a]) standard |
publisher |
Elsevier |
series |
Journal of Lipid Research |
issn |
0022-2275 |
publishDate |
1999-12-01 |
description |
LP[a] is one of the most atherogenic lipoproteins consisting of an LDL-like core particle and a covalently linked glycoprotein of variable size. Due to its structural features, its heterogeneity and instability, there are great difficulties in standardizing quantitative immunochemical Lp[a] assays. One particular problem is the preparation of a pure primary standard, which is sufficiently stable to be used for value assignment of secondary reference material. Here we describe a method to purify Lp[a] to virtual homogeneity. When mixed with glycerol at a ratio of 1:1, the preparation is stable in the deep frozen state for more than 12 months. This latter material gave dose–response curves in several immunochemical assays that were parallel to fresh or frozen sera, freshly prepared Lp[a], and other proposed reference materials. After determination of the protein content by amino acid analysis, it was possible to assign concentrations in molar and mass units to these preparations considering the theoretical molecular weights of the particular apo[a] isoform. Thus we propose to use this procedure for preparation of a “gold standard” for Lp[a] assays.—Kostner, G. M., A. Ibovnik, H. Holzer, and H. Grillhofer. Preparation of a stable fresh frozen primary lipoprotein[a] (LP[a]) standard. |
topic |
DELFIA LDL ELISA glycerol |
url |
http://www.sciencedirect.com/science/article/pii/S0022227520321003 |
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