A mass spectrometry-based strategy for detecting and characterizing endogenous proteinase activities in complex biological samples.

Author(s): Robinson S, Niles RK, Witkowska HE, Rittenbach KJ, Nichols RJ, Sargent JA, Dixon SE, Prakobphol A, Hall SC, Fisher SJ, Hardt M

Publication: Proteomics, 2008, Vol. 8, Page 435-45

PubMed ID: 18186022 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the stability of the saliva subproteome after frozen storage at -30 degrees C for 2 and 6 months.

   Summary of Findings:

   Several peptides were labeled as a result of incubation with an 18-O isotope during frozen storage. Isotope incorporation increased with storage duration (2 versus 6 months), and was prevented when a protease inhibitor cocktail was included prior to freezing, suggesting that proteolysis continues during frozen biospecimen storage. The authors identified histatin 3 as the precursor protein for 3 of the labeled peptides, and kallikrein as an active protease.

   Biospecimens

   • Bodily Fluid - Saliva

   Preservative Types

   • Frozen

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Peptide	MALDI-TOF MS
   Protein	MALDI-TOF MS

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	2 months 6 months
   Analyte Extraction and Purification	Protease inhibitor	Cocktail No protease inhibitor added

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2. Study Purpose

   The purpose of this study was to assess the efficacy of tannins, natural products found in red wine, as protease inhibitors during ex vivo incubation of saliva specimens for 24 h.

   Summary of Findings:

   While tannic acid generated the greatest effect, all tannins investigated were inferior when compared to the protease inhibitor cocktail.

   Biospecimens

   • Bodily Fluid - Saliva

   Preservative Types

   • Frozen

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Peptide	MALDI-TOF MS

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Analyte Extraction and Purification	Protease inhibitor	Cocktail Catechin Epicatechin green Proycyanidin B2 Tannic acid
   Storage	Time at room temperature	24 h

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