Development of Two-Dimensional Liquid Chromatography Coupled with Tandem Mass Spectrometry for Identification of Extracted Proteins of Rice Leaves: Hydrophilic Interaction-Reversed-phase Approach / 分析化学

A two-dimensional liquid chromatography method was developed for the analysis of rice leaves proteomics based on the coupling of hydrophilic interaction liquid chromatography-reversed-phase liquid chromatography with online tandem mass spectrometry. The influence of pH value of chromatographic mobile phase on the orthogonality of the hydrophilic interaction-reversed-phase two-dimensional liquid chromatography was evaluated by the changes of standard peptide retention. The results indicated that the better orthogonality (R2=0.34113) was achieved from the system with hydrophilic interaction columns(pH 9.3) in the first and C18columns(pH 3.3) in the second LC dimension. Coupled with multiple fraction concatenation strategy,the orthogonality of two-dimensional liquid chromatography was further evaluated in the analysis of complex rice leaf proteins. The results showed that more than 50% of the total peptides were identified less than two times, and the peptides obtained from first-dimension were well distributed across the elution window,indicating that the method showed significant orthogonality in the identification of complex rice leaf proteins. Based on the proteome discoverer software,207345 peptides belonged to 2930 protein clusters were identified.

Identification of Peptide Profiling of Deer Antler by Reversed Phase Liquid Chromatography-Tandem Mass Spectrometry and Bioactivities in Simulated Gastrointestinal Digestion / 分析化学

Reversed phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS) was utilized to investigate peptide profiling and bioactivities of antler aqueous extract(AAE),digested antler aqueous extract (AED) and powder(PD). A total of 23,417 and 389 peptides,as well as 15,146 and 75 collagen peptides were identified from AAE, AED and PD, respectively. Angiotensin converting enzyme (ACE) inhibitory activity,dipeptidyl peptidase IV(DPP-IV) inhibitory activity,prolyl endopeptidase(PEP) inhibitory activity and antioxidant activity were used to evaluate the bioactivities of AAE,AED and PD,and it was found that the sequence of their bioactivities was AAE<AED<PD. All the results above proved that AED released more collagen peptides and PD possessed better biological activities. It suggests that the two edible ways of antler are complemented each other and have their own advantages.