alpha-chymotrypsin and benzoylarginine-ethyl-ester

The preparation of capillary microfluidic reactor with co-immobilized trypsin and chymotrypsin with the use of a low-cost commercially available enzymatic reagent (containing these proteases) as well as the evaluation of its usefulness in proteomic research were presented. The monolithic copolymer synthesized from glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) was used as a support. Firstly, the polymerization conditions were optimized and the monolithic bed was synthesized in the fused silica capillary modified with 3-(trimethoxysilyl)propyl methacrylate (γ-MAPS). The polymer containing epoxy groups was then modified with 1,6-diaminohexane, followed by the attachment of glutaraldehyde and immobilization of enzymes. The efficiency of the prepared monolithic Immobilized Enzyme Microreactor (μ-IMER) with regard to trypsin activity was evaluated using the low-molecular mass compound (Nα-benzoyl-l-arginine ethyl ester, BAEE). The activities of both enzymes were investigated using a macromolecular protein (human transferrin, Tf) as a substrate. In the case of BAEE, the reaction product was separated from the substrate using the capillary liquid chromatography and the efficiency of the reaction was determined by the peak area of the substrate. The hydrolysis products of transferrin were analyzed with MALDI-TOF which allows for the verification of the prepared enzymatic system applicability in the field of proteomic research.

Topics: Arginine; Bioreactors; Chromatography, Liquid; Chymotrypsin; Enzymes, Immobilized; Epoxy Compounds; Humans; Methacrylates; Organosilicon Compounds; Polymerization; Proteins; Proteomics; Silanes; Silicon Dioxide; Trypsin

The hydrophobic nature of most membrane proteins severely complicates their extraction, proteolysis and identification. Although detergents can be used to enhance the solubility of the membrane proteins, it is often difficult for a detergent not only to have a strong ability to extract membrane proteins, but also to be compatible with the subsequent proteolysis and mass spectrometric analysis. In this study, we made evaluation on a novel application of sodium laurate (SL) to the shotgun analysis of membrane proteomes. SL was found not only to lyse the membranes and solubilize membrane proteins as efficiently as SDS, but also to be well compatible with trypsin and chymotrypsin. Furthermore, SL could be efficiently removed by phase transfer method from samples after acidification, thus ensuring not to interfere with the subsequent CapLC-MS/MS analysis of the proteolytic peptides of proteins. When SL was applied to assist the digestion and identification of a standard protein mixture containing bacteriorhodoposin and the proteins in rat liver plasma membrane-enriched fractions, it was found that, compared with other two representative enzyme- and MS-compatible detergents RapiGest SF (RGS) and sodium deoxycholate (SDC), SL exhibited obvious superiority in the identification of membrane proteins particularly those with high hydrophobicity and/or multiple transmembrane domains.

Topics: Animals; Arginine; Cell Membrane; Chymotrypsin; Computational Biology; Deoxycholic Acid; Detergents; Lauric Acids; Liver; Mass Spectrometry; Peptide Hydrolases; Proteomics; Rats; Sodium Dodecyl Sulfate; Tandem Mass Spectrometry; Trypsin

Improved in-solution tryptic digestion of proteins in terms of speed and peptide coverage was achieved with the aid of a novel acid-labile anionic surfactant (ALS). Unlike SDS, ALS solubilizes proteins without inhibiting trypsin or other common endopeptidases activity. Trypsin activity was evaluated in the presence of various denaturants; little or no decrease in proteolytic activity was observed in 0.1-1% ALS solutions (w/v). Sample preparation prior to mass spectrometry and liquid chromatography analysis consists of sample acidification. ALS degrades rapidly at low-pH conditions, which eliminates surfactant-caused interference with analysis. Described methodology combines the advantages of protein solubilization, rapid digestion, high peptide coverages, and easy sample preparation for mass spectrometry and liquid chromatography analyses.

Topics: Alkanesulfonates; Angiotensin II; Arginine; Bacteriorhodopsins; Chromatography, High Pressure Liquid; Chymotrypsin; Dioxolanes; Endopeptidases; Hydrogen-Ion Concentration; Hydrophobic and Hydrophilic Interactions; Membrane Proteins; Molecular Structure; Muramidase; Myoglobin; Neurotensin; Ovalbumin; Proteins; Sodium Dodecyl Sulfate; Solubility; Spectrometry, Mass, Electrospray Ionization; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Surface-Active Agents; Trypsin; Ubiquitin; Urea

Trypsin-like and chymotrypsin-like esteroprotease isozymes of the mouse submandibular gland were separated by isoelectric focusing. In normal female mice the following pI-isozyme activities were found; pI-4.6, -5.6 (shoulder), -5.8, -7.1, and -9.9, hydrolytic activities for benzoylarginine ethylester (BAEE) (trypsin-like enzymes), and pI-4.7 and -10.3 hydrolytic activities for acetyltyrosine ethylester (ATEE) (chymotrypsin-like enzymes). In mice with testicular feminization (Tfm mice), only pI4.6 hydrolytic activity for BAEE was found; no ATEE hydrolytic activity was detected. In normal female mice, both 5 alpha-dihydrotestosterone (5 alpha-DHT) and tri-iodo-L-thyronine (T3) significantly increased all these isozymes except the pI-4.6 hydrolytic activity for BAEE. In Tfm mice, T3 also increased all these isozymes except the pI-4.6 hydrolytic activity for BAEE, but 5 alpha-DHT had no effect on any enzymes. These results suggest that the pI-4.6 hydrolytic activity for BAEE is non-inducible by the two hormones. Androgen does not seem to be involved in the inductions of these esteroproteases by T3.

Topics: Androgen-Insensitivity Syndrome; Androgens; Animals; Arginine; Chymotrypsin; Endopeptidases; Enzyme Induction; Female; Isoenzymes; Male; Mice; Submandibular Gland; Triiodothyronine; Trypsin; Tyrosine