Gene cloning, expression, molecular modeling and docking study of the protease SAPRH from Bacillus safensis strain RH12

Utilizing immobilized recombinant serine alkaline protease from Bacillus safensis lab418 in wound healing: Gene cloning, heterologous expression, optimization, and characterization

Microbial proteases have proven their efficiency in various industrial applications; however, their application in accelerating the wound healing process has been inconsistent in previous studies. In this study, heterologous expression was used to obtain an over-yielding of the serine alkaline protease. The serine protease-encoding gene aprE was isolated from Bacillus safensis lab 418 and expressed in E. coli BL21 (DE3) using the pET28a (+) expression vector. The gene sequence was assigned the accession number OP610065 in the NCBI GenBank. The open reading frame of the recombinant protease (aprEsaf) was 383 amino acids, with a molecular weight of 35 kDa. The yield of aprEsaf increased to 300 U/mL compared with the native serine protease (SAFWD), with a maximum yield of 77.43 U/mL after optimization conditions. aprEsaf was immobilized on modified amine-functionalized films (MAFs). By comparing the biochemical characteristics of immobilized and free recombinant enzymes, the former exhibited distinctive biochemical characteristics: improved thermostability, alkaline stability over a wider pH range, and efficient reusability. The immobilized serine protease was effectively utilized to expedite wound healing. In conclusion, our study demonstrates the suitability of the immobilized recombinant serine protease for wound healing, suggesting that it is a viable alternative therapeutic agent for wound management.

Heterologous Expression and Structural Elucidation of a Highly Thermostable Alkaline Serine Protease from Haloalkaliphilic Actinobacterium, Nocardiopsis sp. Mit-7

A highly thermostable alkaline serine protease gene (SPSPro, MN429015) obtained from haloalkaliphilic actinobacteria, Nocardiopsis sp. Mit-7 (NCIM-5746), was successfully cloned and overexpressed in Escherichia coli BL21 under the control of the T7 promoter in the pET Blue1 vector leading to a 20-kDa gene product. The molecular weight of the recombinant alkaline protease, as determined by SDS-PAGE and the Mass Spectrometer (MALDI-TOF), was 34 kDa. The structural and functional attributes of the recombinant thermostable alkaline serine protease were analyzed by Bioinformatic tools. 3D Monomeric Model and Molecular Docking established the role of the amino acid residues, aspartate, serine, and tryptophan, in the active site of thealkaline protease.The activity of the recombinant alkaline protease was optimal at 65 °C, 5 °C higher than its native protease. The recombinant protease was also active over a wide range of pH 7.0-13.0, with a maximal activity of 6050.47 U/mg at pH 9. Furthermore, the thermodynamic parameters of the immobilized recombinant alkaline protease suggested its reduced vulnerability against adverse conditions under which the enzyme has to undergo varied applications.

Gene expression and molecular characterization of recombinant subtilisin from Bacillus subtilis with antibacterial, antioxidant and anticancer properties

This study investigated the multifunctional attributes such as, antibacterial, antioxidant and anticancer potential of recombinant subtilisin. A codon-optimized subtilisin gene was synthesized from Bacillus subtilis and was successfully transformed into E. coli DH5α cells which was further induced for high level expression in E. coli BL21 (DE3). An affinity purified ~40 kDa recombinant subtilisin was obtained that revealed to be highly alkali-thermostable based on the thermodynamic parameters. The kinetic parameters were deduced that indicated higher affinity of N-Suc-F-A-A-F-pNA substrate towards subtilisin. Recombinant subtilisin demonstrated strong antibacterial activity against several pathogens and showed minimum inhibitory concentration of 0.06 μg/mL against B. licheniformis and also revealed high stability under the influence of several biochemical factors. It also displayed antioxidant potential in a dose dependent manner and exhibited cell cytotoxicity against A549 and MCF-7 cancerous cell lines with IC50 of 5 μM and 12 μM respectively. The identity of recombinant subtilisin was established by MALDI-TOF mass spectrum depicting desired mass peaks and N-terminal sequence as MRSK by MALDI-TOF-MS. The deduced N- terminal amino acid sequence by Edman degradation revealed high sequence similarity with subtilisins from Bacillus strains. The structural and functional analysis of recombinant antibacterial subtilisin was elucidated by Raman, circular dichroism and nuclear magnetic resonance spectroscopy and thermogravimetric analysis. The results contribute to the development of highly efficient subtilisin with enhanced catalytic properties making it a promising candidate for therapeutic applications in healthcare industries.

Cloning, Expression, and Structural Elucidation of a Biotechnologically Potential Alkaline Serine Protease From a Newly Isolated Haloalkaliphilic Bacillus lehensis JO-26

An alkaline protease gene of Bacillus lehensis JO-26 from saline desert, Little Rann of Kutch, was cloned and expressed in Escherichia coli BL21 (DE3). A 1,014-bp ORF encoded 337 amino acids. The recombinant protease (APrBL) with Asp 97, His 127, and Ser 280 forming catalytic triad belongs to the subtilase S8 protease family. The gene was optimally expressed in soluble fraction with 0.2 mM isopropyl β-D-thiogalactopyranoside (IPTG), 2% (w/v) NaCl at 28°C. APrBL, a monomer with a molecular mass of 34.6 kDa was active over pH 8–11 and 30°C−70°C, optimally at pH 10 and 50°C. The enzyme was highly thermostable and retained 73% of the residual activity at 80°C up to 3 h. It was significantly stimulated by sodium dodecyl sulfate (SDS), Ca²⁺, chloroform, toluene, n-butanol, and benzene while completely inhibited by phenylmethylsulfonyl fluoride (PMSF) and Hg²⁺. The serine nature of the protease was confirmed by its strong inhibition by PMSF. The APrBL gene was phylogenetically close to alkaline elastase YaB (P20724) and was distinct from the well-known commercial proteases subtilisin Carlsberg (CAB56500) and subtilisin BPN′ (P00782). The structural elucidation revealed 31.75% α-helices, 22.55% β-strands, and 45.70% coils. Although high glycine and fewer proline residues are a characteristic feature of the cold-adapted enzymes, the similar observation in thermally active APrBL suggests that this feature cannot be solely responsible for thermo/cold adaptation. The APrBL protease was highly effective as a detergent additive and in whey protein hydrolysis.

Identification of a novel protease from the thermophilic Anoxybacillus kamchatkensis M1V and its application as laundry detergent additive

A thermostable extracellular alkaline protease (called SAPA) was produced (4600 U/mL) by Anoxybacillus kamchatkensis M1V, purified to homogeneity, and biochemically characterized. SAPA is a monomer with a molecular mass of 28 kDa estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Native-PAGE, casein-zymography, and size exclusion using high performance liquid chromatography (HPLC). The sequence of its NH₂-terminal amino-acid residues showed high homology with those of Bacillus proteases. The SAPA irreversible inhibition by diiodopropyl fluorophosphates (DFP) and phenylmethanesulfonyl fluoride (PMSF) confirmed its belonging to the serine proteases family. Optimal activity of SAPA was at pH 11 and 70 °C. The sapA gene was cloned and expressed in the extracellular fraction of E. coli. The highest sequence identity value (95%) of SAPA was obtained with peptidase S8 from Bacillus subtilis WT 168, but with 16 amino-acids of difference. The biochemical characteristics of the purified recombinant extracellular enzyme (called rSAPA) were analogous to those of native SAPA. Interestingly, rSAPA exhibit a degree of hydrolysis that were 1.24 and 2.6 than SAPB from Bacillus pumilus CBS and subtilisin A from Bacillus licheniformis, respectively. Furthermore, rSAPA showed a high detergent compatibility and an outstanding stain removal capacity compared to commercial enzymes: savinase™ 16L, type EX and alcalase™ Ultra 2.5 L.