Purification and characterization of a novel membrane-bound arginine-specific serine proteinase from porcine intestinal mucosa

Preparation, characterisation and use for antioxidant oligosaccharides of a cellulase from abalone (Haliotis discus hannai) viscera

BACKGROUND

In China, abalone (Haliotis discus hannai) production is growing annually. During industrial processing, the viscera, which are abundant of cellulase, are usually discarded or processed into low-value feedstuff. Thus, it is of interest to obtain cellulase from abalone viscera and investigate its application for preparation of functional oligosaccharides.

RESULTS

A cellulase was purified from the hepatopancreas of abalone by ammonium sulfate precipitation and two-steps column chromatography. The molecular weight of the cellulase was 45 kDa on SDS-PAGE. Peptide mass fingerprinting analysis yielded 103 amino acid residues, which were identical to cellulases from other species of abalone. Substrate specificity analysis indicated that the cellulase is an endo-1,4-β-glucanase. Hydrolysis of seaweed Porphyra haitanensis polysaccharides by the enzyme produced oligosaccharides with degree of polymerisation of two to four, whose monosaccharide composition was 58% galactose, 4% glucose and 38% xylose. The oligosaccharides revealed 2,2'-diphenyl-1-picrylhydrazyl free radical as well as hydrogen peroxide scavenging activity.

CONCLUSION

It is feasible and meaningful to utilise cellulase from the viscera of abalone for preparation of functional oligosaccharides. © 2015 Society of Chemical Industry.

Serine proteases of small intestine mucosa--localization, functional properties, and physiological role

In this review we present data about small intestine serine proteases, which are a considerable part of the proteolytic apparatus in this major part of the gastrointestinal tract. Serine proteases of intestinal epitheliocytes, their structural-functional features, cellular localization, physiological substrates, and mechanisms of activity regulation are examined. Information about biochemical and functional properties of serine proteases is presented in a common context with morphological and physiological data, this being the basis for understanding the functional processes taking place in upper part of the intestine. Serine proteases play a key role in the physiology of the small intestine and provide the normal functioning of this organ as part of the digestive system in which hydrolysis and suction of food substances occur. They participate in renewal and remodeling of tissues, retractive activity of smooth musculature, hormonal regulation, and defense mechanisms of the intestine.

Serase-1B, a new splice variant of polyserase-1/TMPRSS9, activates urokinase-type plasminogen activator and the proteolytic activation is negatively regulated by glycosaminoglycans

Polyserase-1 (polyserine protease-1)/TMPRSS9 (transmembrane serine protease 9) is a type II transmembrane serine protease (TTSP) that possesses unique three tandem serine protease domains. However, the physiological function of each protease domain remains poorly understood. We discovered a new splice variant of polyserase-1, termed Serase-1B, which contains 34 extra amino acids consisting a SEA module (a domain found in sea urchin sperm protein, enterokinase and agrin) adjacent to the transmembrane domain and the first protease domain with a mucin-like box at the C-terminus. The tissue distribution of this enzyme by RT (reverse transcription)-PCR analysis revealed high expression in the liver, small intestine, pancreas, testis and peripheral blood CD14+ and CD8+ cells. To investigate the role of Serase-1B, a full-length form recombinant protein was produced. Interestingly, recombinant Serase-1B was partly secreted as a soluble inactive precursor and it was also activated by trypsin. This activated enzyme selectively cleaved synthetic peptides for trypsin and activated protein C, and it was inhibited by several natural serine protease inhibitors, such as aprotinin, alpha2-antiplasmin and plasminogen activator inhibitor 1. In addition, Serase-1B efficiently converted pro-uPA (urokinase-type plasminogen activator) into active uPA and this activation was strongly inhibited by these natural inhibitors. Furthermore, this activation was also negatively regulated by glycosaminoglycans. Our results indicate that Serase-1B is a novel member of TTSPs that might be involved in uPA/plasmin-mediated proteolysis and possibly implicated in biological events such as fibrinolysis and tumour progression.

Further Characterization of a Sarcoplasmic Serine Proteinase from the Skeletal Muscle of White Croaker (Argyrosomus argentatus)

A trypsin-type serine proteinase (WSP) was purified previously from the sarcoplasmic fraction of skeletal muscle of white croaker (Argyrosomus argentatus) by Yanagihara et al. ((1991) Nippon Suisan Gakaishi, 57, 133-142). However, further research on WSP was not carried out. In the present study, we determined the N-terminal amino acid sequence of this enzyme (27 amino acid residues), which revealed relatively high identity in the conserved region to other trypsin-type serine proteinases. Degradation action of WSP on neuropeptides is also reported in this manuscript. The results show that WSP only cleaves at the carboxyl side of Arg or Lys residue of the peptides, especially between dibasic amino acid residues such as Arg-Arg and Arg-Lys.

Purification and characterization of myofibril-bound serine protease from lizard fish (Saurida undosquamis) muscle

Myofibril-bound serine protease (MBSP) from lizard fish (SAURIDA UNDOSQUAMIS: Synodontidae) skeletal muscle was purified to homogeneity with higher purification (1260-fold) and higher recovery (7%) than our previous report in lizard fish (Saurida wanieso). The new purification method combines a heat-treatment for dissociation from washed myofibrils, acid-treatment at pH 5.0 before and after lyophilization, and alcohol-treatment, followed by two column chromatographies. The molecular mass of the enzyme was estimated to be 50 kDa under non-reducing conditions and 28 kDa under reducing conditions by SDS-PAGE. The N-terminal amino acid sequence of the MBSP was determined to be 22 residues (IVGGYEXEAYSKPYQVSINLGY) and the sequence showed high homology to carp and other fish trypsins (64-77%), but did not show high homology to carp MBSP (41%). The enzyme activity was inhibited by serine protease inhibitors such as Pefabloc SC, leupeptin, TLCK and native protein inhibitors (soybean trypsin inhibitor, alpha(1)-antitrypsin and aprotinin). The purified enzyme specifically hydrolyzed at the carboxyl side of the arginine residue of synthetic 4-methyl-coumaryl-7-amide substrate. When purified MBSP was stored at -35 degrees C in the presence of 50% ethylene glycol (V/V), the enzyme activity was entirely preserved over 6 months and stable against freezing and thawing. Activities for both casein and the synthetic substrate were most active at pH 9.0, and the enzyme was most active approximately 55 degrees C with casein and between 35 and 45 degrees C for synthetic substrate. When myofibrils were incubated with purified MBSP, myosin heavy chain was mostly degraded approximately 55 degrees C, but the degradation of actin was very slow.

Purification and characterization of heat-stable alkaline proteinase from bigeye snapper (Priacanthus macracanthus) muscle

Heat-stable alkaline proteinase was purified from bigeye snapper (Priacanthus macracanthus) ordinary muscle by heat-treatment and a series of chromatographies including Phenyl-Sepharose 6 Fast Flow, Source 15Q and Superose 12 HR 10/30. It was purified to 5180-fold with a yield of 0.8%. The molecular weight of purified proteinase was estimated to be 72 kDa by gel filtration. The proteinase appeared as two proteinase activity bands with molecular weights of 66 and 13.7 kDa on non-reducing SDS-substrate gel. Accordingly, it was found to consist of two different subunits. The optimum pH and temperature for casein hydrolysis were 8.5 and 60 degrees C, respectively. The proteolytic activity was strongly inhibited by soybean trypsin inhibitor and partially inhibited by ethylenediaminetetraacetic acid, while pepstatin A and E-64 showed no inhibition. Purified proteinase was able to hydrolyze Boc-Phe-Ser-Arg-MCA, but rarely hydrolyzed Z-Phe-Arg-MCA and Z-Arg-Arg-MCA. In addition, it mainly degraded myosin heavy chain, not actin. These results suggest that purified proteinase was serine proteinase, which is probably involved in gel weakening of bigeye snapper surimi.

Cloning and Characterization of a Transmembrane-Type Serine Protease from Rat Kidney, a New Sodium Channel Activator

We have cloned the gene of a new transmembrane-type serine protease from rat kidney, which activates sodium channels. The amino acid sequence deduced from a full-length cDNA revealed that transmembrane serine protease-1 (TMSP-1) is a member of the clan SA/family S1 of serine proteases, comprising a 30 amino acid prepropeptide, a mature form sequence of 274 amino acids starting with the Ile-Val-Gly-Gly-Gln motif, and a common catalytic triad of serine proteases. The hydrophobic amino acid sequence in the carboxy-terminus of this enzyme suggests that it is a glycosylphosphatidylinositol-anchored protein. As revealed by quantitative reverse transcription-polymerase chain reaction analysis, it is highly expressed in kidney, small intestine, and stomach, and moderately expressed in lung, thymus, spleen and skin. The recombinant protease had an optimal pH at 9.0, selectively cleaved synthetic peptide substrates of trypsin, and was inhibited by aprotinin, leupeptin and benzamidine. Immunohistochemical studies revealed that this protease is predominantly expressed in cells from collecting ducts of the renal medulla. We also demonstrate that a C-terminally truncated variant of TMSP-1 significantly activates the epithelial sodium channel, and that its mRNA levels are upregulated by aldosterone. These observations suggest that it is a new member of the trypsin-type transmembrane proteases, which regulate sodium balance by activating the epithelial sodium channel.

Anterograde axonal transport of Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme in rat sciatic nerves: cleavage occurs between basic residues

Axonal transport of Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme activity was studied in rat sciatic nerves from 12 to 120 h after double ligations. The anterograde axonal transport increased and peaked 72 h after ligation. The optimum pH for Boc-Arg-Val-Arg-Arg-MCA hydrolyzing enzyme activity was 6.5 to 6.9 and did not require Ca(2+) for the activity. Two molecular forms with enzyme activity were identified by size-exclusion chromatography and the molecular masses of the two enzymes were estimated to be 98 and 52 kDa. Two enzyme activities were strongly inhibited by Hg(2+), Cu(2+) and trypsin inhibitors such as TLCK, antipain and leupeptin. It cleaved the substrate, Boc-Arg-Val-Arg-Arg-MCA, between the dibasic sequence Arg-Arg, and needed a support of aminopeptidase B-like enzyme activity for the liberation of 7-amino-4-methylcoumarin. These results suggest that the enzyme is transported in rat sciatic nerves and involved in the post-translational processing of precursor proteins under the anterograde axonal transport. But there is absolutely no evidence for a role in precursor processing and such a putative role is purely speculative.

Identification of a myofibril-bound serine proteinase (MBSP) in the skeletal muscle of lizard fish Saurida wanieso which specifically cleaves the arginine site

A myofibril-bound serine proteinase (MBSP) from the skeletal muscle of lizard fish (Saurida wanieso) was purified to homogeneity by a heating treatment followed by a series of column chromatographies on DEAE-Sephacel, Sephacryl S-200, Q-Sepharose, Hydroxyapatite and Benzamidine-Sepharose 6B, and characterized enzymatically. On SDS-poly-acrylamide gel electrophoresis (SDS-PAGE), the purified enzyme showed a band with molecular mass of approximately 29 kDa under reducing conditions, while 60 kDa under non-reducing conditions. The optimum temperature of the enzyme was 50 degrees C using t-butyloxycarbonyl-Phe-Ser-Arg-4-methylcoumaryl-7-amide (Boc-Phe-Ser-Arg-MCA) as a substrate. Substrate specificity analysis both using MCA-substrates and peptides showed that MBSP specifically cleaved at the carboxyl side of the arginine residue. Inhibitor susceptibility analysis revealed that MBSP was inhibited effectively by Pefabloc SC, soybean trypsin inhibitor (STI) and aprotinin, indicating the characteristic of a serine proteinase. When myofibril was incubated with the enzyme, it optically degraded myosin heavy chain at 55-60 degrees C, while alpha-actinin and actin were not at all hydrolyzed as detected by immunoblotting. The N-terminal amino acid sequence of MBSP was partially determined as IVGGAEXVPY- and was very homologous to other serine proteases.

Cleavage specificity of a myofibril-bound serine proteinase from carp (Cyprinus carpio) muscle

Previously, we reported the purification and characterization of a myofibril-bound serine proteinase (MBP) from carp muscle (Osatomi K, Sasai H, Cao M-J, Hara K, Ishihara T. Comp Biochem Physiol 1997;116B:159-66). In the present study, the N-terminal amino acid sequence of the enzyme was determined, which showed high identity with those of other trypsin-like serine proteases. The cleavage specificity of MBP for dibasic and monobasic residues was investigated using various fluorogenic substrates and peptides. Analyses of the cleaved peptide products showed that the enzyme hydrolyzed peptides both at monobasic and dibasic amino acid residues. Monobasic amino acid residues were hydrolyzed at the carboxyl side; dibasic residues were cleaved either at the carboxyl side of the pair or between the two basic residues and the enzyme showed a cleavage preference for the Arg-Arg pair. Unexpectedly, MBP hydrolyzed lysyl-bradykinin and methionyl-lysyl-bradykinin at the carboxyl side of Gly fairly specifically and efficiently displaying a unique cleavage. Because MBP also degraded protein substrates such as casein and myofibrillar proteins, the substrate specificity of MBP appeared not to be strictly specific.

Purification and characterization of myofibril-bound serine proteinase from carp Cyprinus carpio ordinary muscle

1. A novel myofibril-bound serine proteinase (MBP) has been purified from ordinary muscle of the carp Cyprinus carpio. 2. It was solubilized from the myofibril fraction with acid treatment (under the conditions of 0.6 M KCl, pH 4.0), then purified by column chromatographic steps on Ultrogel AcA 54, and Arginine-Sepharose 4B. 3. The purified enzyme revealed a single protein band on SDS-PAGE, and its molecular mass was estimated to be 30 kDa by SDS-PAGE and gel filtration. 4. The optimum pH and temperature of the enzyme were 8.0 and 55 degrees C, respectively, when Boc-Phe-Ser-Arg-MCA and casein were used as substrates. 5. The enzyme hydrolyzed Boc-Gln-Arg-Arg-MCA most rapidly, and also hydrolyzed the substrates for trypsin-type proteinase, but not for chymotrypsin. The enzyme was inhibited by serine proteinase inhibitors such as DFP, STI and leupeptin. These results suggested that the enzyme was a trypsin-type serine proteinase. 6. Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the purified enzyme was reduced by addition of NaCl, but the caseinolytic activity and Boc-Phe-Ser-Arg-MCA hydrolyzing activity of the partially purified enzyme were activated by NaCl.

Purification and characterization of hepsin from rat liver microsomes

Hepsin, a putative cell-surface serine proteinase, has been isolated from the microsomal membranes of rat liver and purified to homogeneity by hydroxyapatite, DEAE-Sepharose, and benzamidine-Sepharose chromatography. The course of purification was monitored using antibodies raised against a 20-mer peptide at the C-terminus of rat hepsin, and the identity of the purified protein was confirmed by partial amino-acid sequencing. A single-chain precursor of ca. 50 kDa found in the microsomes underwent spontaneous maturation in the course of purification so that the last, affinity chromatography, step recovered only the mature form which dissociated to subunits of 31 and 19 kDa under reducing SDS-PAGE. Proteinase digestion experiments with microsomal vesicles are consistent with the luminal orientation of the precursor C-terminus, which would result in its extracellular orientation upon transportation to the cell surface. [3H]diisopropylfluorophosphate covalently binds to the large subunit showing it to be the catalytic one. The N-terminal sequencing of this subunit demonstrates that the zymogen is converted to the active serine proteinase by cleavage at the Arg161-Ile162 site. Activity measurements with short synthetic peptides show that the enzyme cleaves after basic amino-acid residues, Arg being preferable to Lys. The inhibition pattern is typical of trypsin-like serine proteinases. The pH-dependence of activity within the range pH 6-9 has no maximum, the activity increasing continuously with pH. These results are consistent with the earlier predictions based on hepsin amino-acid sequence and elucidate the specificity and other earlier unknown enzymatic and molecular properties of the enzyme.