Peptides recovery

The greater amount of peptide/protein identification in the RP-RP experiment is likely related to higher peptide recovery from the first LC dimension. In addition, a... 

Speicher, K. D., Kolbas, O., Harper, S., and Speicher, D. W., Systematic analysis of peptide recoveries from in-gel digestions for protein identification in proteome studies.. Journal of Biomolecular Techniques 11(2), 74-86, 2000. 

Table I Peptide Recovery after Enzymatic Digestion of PVDF-Bound Protein in the Presence of Various Detergents...

Detergent Transferrin Peptide Recovery S (%) STI Peptide Recovery s (%) ... 

In summary, octylglucopyranoside can be substituted for RTX-100 with only a slight decrease in peptide recoveries. Decylglucopyranoside may be used in place of RTX-100 when acetonitrile is added to the digestion buffer, but is not useful for endoproteinase Glu-C. Heptyl and nonyl glucopyranosides are not suitable alternatives as there was no peptides recover with the former and micelle formation occurred with the latter. 

Table II. Summary of peptide recoveries using several internal amino acid sequencing strategies...

It has been noted by us and others (4) that a wide, diffuse band gives less optimal digestion and recovery. Therefore, when excising a band or a gel slice for digestion, cutting was done conservatively. Limiting the area of PVDF or gel involved in this technique improved peptide recovery. 

B. Peptide recovery from the PVDF method based on peak areas... 

In order to compare peptide recovery from proteolysis in solution, in gel and on PVDF membrane, we digested the same amount of BSA (2.5 ig each, 35 pmol). Figure 1 shows chromatograms of peptides from Lys-C digestion of reduced and denatured BSA without alkylation (A), or with the addition of either iodoacetamide (B), or 4-vinylpyridine (C). As was demonstrated before (Stone et al. 1989), it is clear that BSA was not efficiently digested, as indicated by the low intensity of the peptide peaks when it was not alkylated. On the other hand, alkylated BSA, either by iodoacetamide (B) or 4-vinylpyridine (C), were digested much better, as indicated by the higher intensity of the peaks and the number of peaks. 

MF processing for clarification and defatting of cheese whey, selective separation and concentration of micellar caseins from milk for various purposes, fractionation of caseins and their peptides, recovery of native whey proteins (WPs) from miUc, gentle sterilization of milk to produce extended shelf life liquid miUc and cheese milk, the fractionation of globular miUc fat and its components, the reduction of microorganisms in cheese brine, and the removal of colloidal particles in membrane-cleaning solutions... 

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