Disease relevance of PRSS7

• Expression, purification, and characterization of a biologically active bovine enterokinase catalytic subunit in Escherichia coli [1].

High impact information on PRSS7

• Cloning and functional expression of a cDNA encoding the catalytic subunit of bovine enterokinase [2].
• Enterokinase (enteropeptidase) is a heterodimeric serine protease that is responsible for the physiological activation of trypsinogen by highly specific cleavage of the trypsinogen activation peptide following the sequence (Asp)4-Lys [2].
• Incubation of the soybean phospholipid and brush-border membrane vesicles with papain released the exposed molecules of enterokinase [3].
• Enterokinase is predominantly present as membrane fragments which must be treated with Triton X-100 to release the enzyme [4].
• The properties of enterokinase in phospholipid vesicles were compared with those of alkaline phosphatase, which was also added to the reconstitution system, and with the enzyme activities present in vesicles prepared from brush-border membranes [3].

Biological context of PRSS7

• Enterokinase and alkaline phosphatase had their active sites exposed to substrate in the brush-border membrane vesicles [3].
• Of the zymogens of the serine proteases tested, including several of those involved in blood coagulation, only native and guanidinated trypsinogen are acitvated by enterokinase, whereas acetylated trypsinogen is not [5].
• Partial heat denaturation of bovine enterokinase causes a differential response toward the activation of trypsinogen and the hydrolysis of benzoyl-L-arginine ethyl ester (BZArgOEt), further suggesting that secondary sites are important in the binding of trypsinogen [5].
• Hormonal combination of insulin (17 nmol.l(-1)) plus cortisol (138 nmol.l(-1)) or insulin plus recombinant enterokinase linker bST (4.5 nmol.l(-1) increased lipogenesis (P<0.05) [6].

Anatomical context of PRSS7

• Bovine enterokinase was purified from duodenal mucosa [7].
• Enterokinase (EC 3.4.21.9) is a serine proteinase in the duodenum that exhibits specificity for the sequence (Asp)(4)-Lys [1].
• A 1:1 mixture of the control bile and pancreatic juice was mixed with bovine enterokinase (10 mg/ml), and the mixture was incubated at 37 degrees C for 12 h [8].
• Recently, a cDNA encoding the catalytic (light) chain of bovine enterokinase (EKL) was identified, characterized, and transiently expressed in mammalian COS cells [9].

Associations of PRSS7 with chemical compounds

• Enterokinase hydrolyzed lysine and arginine substrates and slowly reacted with the trypsin active site titrant 4-methylumbelliferyl-p-guanidinobenzoate [7].
• We altered the trypsinogen native propeptide sequence by replacing the lysine at position 6 with an aspartic acid, thus destroying the site in the propeptide cleaved by enterokinase and by trypsin [10].
• The recombinant intact EK catalytic subunit was purified to homogeneity with a specific activity of 720 AUs/mg protein through ammonium sulfate precipitation, DEAE chromatography, and gel filtration [1].
• After the his-tagged apo-NCS protein had been purified and cleaved with enterokinase, the binding properties of the recombinant protein as to ethidium bromide (EtBr) were studied by monitoring of total fluorescence intensity and fluorescence polarization with a BEACON 2000 system and GraphPad Prism software [11].

Regulatory relationships of PRSS7

• Bovine enterokinase was inhibited by Kunitz pancreatic trypsin inhibitor with a Kassoc of 2 X 10(8) M-1 and only weakly by other proteinase inhibitors [7].

Other interactions of PRSS7

• Upon proteolytic digestion of GIP with the staphylococcal V8 protease and with enterokinase, two fragments are formed in each case, corresponding to GIP1-3, GIP4-42, and GIP1-16, GIP17-42, respectively [12].
• Milk production, plasma bovine somatotropin (bST) and insulin-like growth factor I (IGF-I) were measured in dairy cows following a single subcutaneous injection of a slowly released preparation of either recombinant enterokinase linker bST (somidobove: 640 mg) or recombinant methionyl bST (sometribove: 500 mg) [13].

Analytical, diagnostic and therapeutic context of PRSS7

• The regenerated protein behaved as native trypsinogen as judged by gel exclusion chromatography, isoelectric focusing, and activation with bovine enterokinase or trypsin [14].
• A direct high-performance liquid chromatography assay of the enzymatic activity of enterokinase (enteropeptidase) [15].
• A novel form of gastric inhibitory polypeptide (GIP) isolated from bovine intestine using a radioreceptor assay. Fragmentation with staphylococcal protease results in GIP1-3 and GIP4-42, fragmentation with enterokinase in GIP1-16 and GIP17-42 [12].
• Immobilized nickel affinity chromatography yielded a partially purified recombinant CFT, which exhibited trypsin-specific activity after activation with bovine enterokinase [16].
• METHODS: Bovine enterokinase catalytic subunit cDNA was obtained by RT-PCR from duodenal mucosa of a bovine obtained at wholesale market, and then cloned into a pUCmT cloning vector and sequenced [17].

References