跳转至内容
Merck
CN
  • Towards absolute quantification of allergenic proteins in food--lysozyme in wine as a model system for metrologically traceable mass spectrometric methods and certified reference materials.

Towards absolute quantification of allergenic proteins in food--lysozyme in wine as a model system for metrologically traceable mass spectrometric methods and certified reference materials.

Journal of AOAC International (2014-03-22)
Adam Cryar, Caroline Pritchard, William Burkitt, Michael Walker, Gavin O'Connor, Duncan Thorburn Burns, Milena Quaglia
摘要

Current routine food allergen quantification methods, which are based on immunochemistry, offer high sensitivity but can suffer from issues of specificity and significant variability of results. MS approaches have been developed, but currently lack metrological traceability. A feasibility study on the application of metrologically traceable MS-based reference procedures was undertaken. A proof of concept involving proteolytic digestion and isotope dilution MS for quantification of protein allergens in a food matrix was undertaken using lysozyme in wine as a model system. A concentration of lysozyme in wine of 0.95 +/- 0.03 microg/g was calculated based on the concentrations of two peptides, confirming that this type of analysis is viable at allergenically meaningful concentrations. The challenges associated with this promising method were explored; these included peptide stability, chemical modification, enzymatic digestion, and sample cleanup. The method is suitable for the production of allergen in food certified reference materials, which together with the achieved understanding of the effects of sample preparation and of the matrix on the final results, will assist in addressing the bias of the techniques routinely used and improve measurement confidence. Confirmation of the feasibility of MS methods for absolute quantification of an allergenic protein in a food matrix with results traceable to the International System of Units is a step towards meaningful comparison of results for allergen proteins among laboratories. This approach will also underpin risk assessment and risk management of allergens in the food industry, and regulatory compliance of the use of thresholds or action levels when adopted.

材料
Product Number
品牌
产品描述

Sigma-Aldrich
Lysozyme 来源于鸡蛋白, powder or granules, ≥39,000 units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, lyophilized powder, BioReagent, suitable for cell culture, 1,000-2,000 BAEE units/mg solid
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, TPCK Treated, essentially salt-free, lyophilized powder, ≥10,000 BAEE units/mg protein
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, BioUltra, lyophilized powder, ≥98% (SDS-PAGE), ≥40,000 units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, Type IX-S, lyophilized powder, 13,000-20,000 BAEE units/mg protein
Sigma-Aldrich
溶菌酶 人, Lysobac, recombinant, expressed in rice, lyophilized powder, ≥100,000 units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, lyophilized powder, Type II-S, 1,000-2,000 units/mg dry solid
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, powder, ≥7,500 BAEE units/mg solid
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, powder (crystalline), 70000-140000 U/mg
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, Type I, ~10,000 BAEE units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, suitable for protein sequencing, lyophilized powder
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, 10 mg/mL
Sigma-Aldrich
Lysozyme 氯化物形式 来源于鸡蛋白, Grade VI, ≥35,000 units/mg protein (E1%/282)
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, essentially salt-free, lyophilized powder, ≥9,000 BAEE units/mg protein, BioReagent, suitable for cell culture
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, TPCK Treated, essentially salt-free, lyophilized powder, ≥10,000 BAEE units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, lyophilized powder, γ-irradiated, BioXtra, suitable for cell culture, 1,000-2,000 BAEE units/mg solid
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, Type XI, lyophilized powder, ≥6,000 BAEE units/mg protein
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, tablet, 1 mg tablet
Sigma-Aldrich
TrypZean® 牛, recombinant, expressed in corn, lyophilized powder, ≥3,350 units/mg solid (USP)
Sigma-Aldrich
胰蛋白酶 来源于猪胰腺, ~1500 U/mg
Sigma-Aldrich
乙酰化胰蛋白酶 来源于牛胰腺, Type V-S, ≥8,500 BAEE units/mg protein (biuret)
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, dialyzed, lyophilized, powder, ~100000 U/mg
Sigma-Aldrich
胰蛋白酶 来源于人类胰腺, salt-free, lyophilized powder, vial of ≥1,000 BAEE units
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, For use as a marker in SDS-PAGE
Sigma-Aldrich
胰蛋白酶 来源于牛胰腺, ≥2,500 USP units/mg solid, meets USP testing specifications
Sigma-Aldrich
Lysozyme 来源于鸡蛋白, aseptically filled
Sigma-Aldrich
溶菌酶 来源于人类中性粒细胞, ≥95% (SDS-PAGE), lyophilized powder, ≥100,000 units/mg protein (E1%/280)
Supelco
Lysozyme 来源于鸡蛋白, VETRANAL®, analytical standard