Plasma protein profiling: unique and stable features of individuals.
Author(s): Nelsestuen GL, Zhang Y, Martinez MB, Key NS, Jilma B, Verneris M, Sinaiko A, Kasthuri RS
Publication: Proteomics, 2005, Vol. 5, Page 4012-24
PubMed ID: 16130168 PubMed Review Paper? No
Suggested by: ISBER
Purpose of Paper
The purpose of this paper was to determine the reproducibility of MALDI-TOF protein profiles over time within individuals.
Conclusion of Paper
With ZipTip extraction, reproducible protein profiles were obtained from healthy individuals both when multiple specimens were collected within a 5 hour period in one day or years apart. Homologous peak intensity ratios (peaks representing minor modifications to the same parent polypeptide) were unaffected by the volume of the sample spotted but heterologous peak intensity ratios changed significantly once a threshold sample size was exceeded. Up to 10 freeze-thaw cycles had very little effect on plasma protein profiles. Protein profile changes were noted in specimens from individuals with sepsis and graft versus host disease.
Studies
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Study Purpose
The purpose of this study was to determine the effects of multiple specimen collections from individuals over time, patient age, freeze-thaw cycling, disease, and sample volume on MALDI-TOF protein profiles from ZipTip extraction of serum and plasma. Plasma was stored at -70 degrees C while serum was stored at -80 degrees C until analysis.
Summary of Findings:
With ZipTip extraction, reproducible protein profiles were obtained from healthy individuals both when multiple specimens were collected within a 5 hour period in one day or years apart. This was true for both adolescents and adults and effects of age were only observed for transthyretin (TTr). Homologous peak intensity ratios (peaks representing minor modifications to the same parent polypeptide) were unaffected by the volume of the sample spotted, but heterologous peak intensity ratios changed significantly once a threshold sample size was exceeded. Up to 10 freeze-thaw cycles over a 4 month storage period had very little effect on plasma protein profiles, with the exception of a significant increase in one peak arising when apoCIII1 loses sialic acid residues. Protein profile changes were noted in specimens from individuals with sepsis and graft versus host disease.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
- Other diagnoses
Platform:
Analyte Technology Platform Peptide MALDI-TOF MS Protein MALDI-TOF MS Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Acquisition Anticoagulant Sodium citrate
Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Preaquisition Diagnosis/ patient condition Sepsis and graft versus host disease
Analyte Extraction and Purification Analyte isolation method ZipTip extraction
Biospecimen Aliquots and Components Aliquot size/volume 0.1 uL
0.5 uL
2.0 uL
Biospecimen Acquisition Time of biospecimen collection Time 0
4 h
5 h
3 y
2-4 y
6 y
Preaquisition Patient age Adolescent
Adult
Storage Freeze/thaw cycling 10 cycles