TY  - JOUR
A1  - Alker, Wiebke
A1  - Schwerdtle, Tanja
A1  - Schomburg, Lutz
A1  - Haase, Hajo
T1  - A Zinpyr-1-based Fluorimetric Microassay for Free Zinc in Human Serum
JF  - International journal of molecular sciences
N2  - Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual’s zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body’s zinc status, and its suitability as a future biomarker for an individual’s zinc status.
KW  - zinc
KW  - free zinc
KW  - serum
KW  - biomarker
KW  - fluorescent probe
KW  - Zinypr-1
Y1  - 2019
U6  - https://doi.org/10.3390/ijms20164006
SN  - 1661-6596
SN  - 1422-0067
VL  - 20
IS  - 16
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Gericke, Beate
A1  - Wolfram, Wiebke
A1  - Kaisers, Udo
A1  - Dudenhausen, Joachim W.
T1  - Peptide and protein profiles in serum and follicular fluid of women undergoing IVF
JF  - Human reproduction
N2  - BACKGROUND: Proteins and peptides in human follicular fluid originate from plasma or are produced by follicular structures. Compositional changes reflect oocyte maturation and can be used as diagnostic markers. The aim of the study was to determine protein and peptide profiles in paired serum and follicular fluid samples from women undergoing IVF. METHODS: Surface-enhanced laser desorption and ionization-time of flight-mass spectrometry (SELDI-TOF-MS) was used to obtain characteristic protein pattern. RESULTS: One hundred and eighty-six individual MS signals were obtained from a combination of enrichment on strong anion exchanger (110), weak cation exchanger (52) and normal phase surfaces (24). On the basis of molecular masses, isoelectric points and immunoreactivety, four signals were identified as haptoglobin (alpha(1)- and alpha(2)-chain), haptoglobin 1 and transthyretin (TTR). Immunological and MS characteristics of the TTR : retinol-binding protein (RBP) transport complex revealed no microheterogeneity differences between serum and follicular fluid. Discriminatory patterns arising from decision-tree-based classification and regression analysis distinguished between serum and follicular fluid with a sensitivity and specificity of 100%. CONCLUSIONS: Quantitative and qualitative differences indicate selective transport processes rather than mere filtration across the blood-follicle barrier. Identified proteins as well as characteristic peptide and/or protein signatures might emerge as potential candidates for diagnostic markers of follicle and/or oocyte maturation and thus oocyte quality.
KW  - human follicular fluid
KW  - peptide
KW  - protein
KW  - proteome
KW  - serum
Y1  - 2006
U6  - https://doi.org/10.1093/humrep/del257
SN  - 0268-1161
VL  - 21
IS  - 11
SP  - 2960
EP  - 2968
PB  - Univ. Press
CY  - Oxford
ER  -