title: Dipeptidyl peptidase-II from probiotic Pediococcus acidilactici: Purification and functional characterization.
abstract: Dipeptidylpeptidase-II (DPP-II, E.C. 3.4.14.2), an exopeptidase was purified 15.4 fold with specific activity and yield of 15.4U/mg/mL and 14.68% respectively by a simple two step procedure from a probiotic Pediococcus acidilactici. DPP-II is 38.7KDa homodimeric serine peptidase with involvement of His and subunit mass of 18.9KDa. The enzyme exhibited optimal activity at pH 7.0 and 37°C with activation energy of 24.97kJ/mol. The enzyme retained more than 90% activity upto 50°C thus adding industrial importance. DPP-II hydrolysed Lys-Ala-4mβNA with KMof 50μM and Vmaxof 30.8nmol/mL/min. In-silico characterization studies of DPP-II on the basis of peptide fragments obtained by MALDI-TOF revealed an evolutionary relationship between DPP-II of prokaryotes and phosphate binding proteins. Secondary and three-dimensional structure of enzyme was also deduced by in-silico approach. Functional studies of DPP-II by TLC and HPLC-analysis of collagen degraded products revealed that enzyme action released free amino acids and other metabolites. Microscopic and SDS-PAGE analysis of enzyme treated analysis of chicken's chest muscle (meat) hydrolysis revealed change and hydrolysis of myofibrils. This may affect the flavor and texture of meat thereby suggesting its role in meat tenderization. Being a protein of LAB (Lactic acid bacteria), it is also expected to be safe.
authors.affiliation: Department of Biochemistry, Kurukshetra University, Kurukshetra, India. Electronic address: dimpigandhi88@gmail.com.
authors.forename: Dimpi
authors.initials: D
authors.lastname: Gandhi
authors.affiliation: Department of Biochemistry, Kurukshetra University, Kurukshetra, India. Electronic address: preetichanalia18@gmail.com.
authors.forename: Preeti
authors.initials: P
authors.lastname: Chanalia
authors.affiliation: Department of Biochemistry, Kurukshetra University, Kurukshetra, India. Electronic address: virgopooja85@gmail.com.
authors.forename: Pooja
authors.initials: P
authors.lastname: Attri
authors.affiliation: Department of Biochemistry, Kurukshetra University, Kurukshetra, India. Electronic address: dhanda.suman999@gmail.com.
authors.forename: Suman
authors.initials: S
authors.lastname: Dhanda
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D020134:Catalytic Domain; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000737:chemistry; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry* / Q000302:isolation & purification; D004795:Enzyme Stability; D005511:Food Handling; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008460:Meat; D008958:Models, Molecular; D008970:Molecular Weight; D000070016:Pediococcus acidilactici / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D003094:Collagen; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C100151:dipeptidyl peptidase II
keywords: Dipeptidyl peptidase-II; Meat tenderization; Pediococcus acidilactici