Characterization of a Hyaluronic Acid Utilization Locus and Identification of Two Hyaluronate Lyases in a Marine Bacterium Vibrio alginolyticus LWW-9

A comprehensive review on microbial hyaluronan-degrading enzymes: from virulence factors to biotechnological tools

Hyaluronan (HA), a natural high molecular weight polysaccharide, has extensive applications in cosmetology and medical treatment. Hyaluronan-degrading enzymes (Hyals) act as molecular scissors that cleave HA by breaking the glucosidic linkage. Hyals are present in diverse organisms, including vertebrates, invertebrates and microorganisms, and play momentous roles in biological processes. In recent years, microbial Hyals (mHyals) have gained considerable attention for their exceptional performance in the production and processing of HA. Moreover, the applications of mHyals have been greatly extended to various biomedical fields. To explore the potential applications of mHyals, a thorough comprehension is imperative. In this context, this review systematically summarizes the sources, structures, mechanisms and enzymatic properties of mHyals and discusses their biological functions in host invasion, disease development, and regulation of intestinal flora. Furthermore, versatile applications inspired by their biological functions in medicine development, molecular biology, and industrial biotechnology are comprehensively reviewed. Finally, prospects are presented to emphasize the importance of exploration, expression and characterization of mHyals and the necessity of excavating their potential in biotechnological fields.

Biochemical Characterization of Hyaluronate Lyase CpHly8 from an Intestinal Microorganism Clostridium perfringens G1121

Hyaluronic acid (HA) is an important component of extracellular matrices (ECM) and a linear polysaccharide involved in various physiological and pathological processes within the biological system. Several pathogens exploit HA degradation within the extracellular matrix to facilitate infection. While many intestinal microorganisms play significant roles in HA utilization in the human body, there remains a scarcity of related studies. This paper addressed this gap by screening intestinal microorganisms capable of degrading HA, resulting in the isolation of Clostridium perfringens G1121, which had been demonstrated the ability to degrade HA. Subsequent genome sequencing and analysis of C. perfringens G1121 revealed its utilization of the polysaccharide utilization loci of HA (PULHA), which was obtained by horizontal gene transfer. The PULHA contains a sequence encoding a hyaluronic acid-specific degradation enzyme designated CpHly8, belonging to polysaccharide lyase family 8. The specific activity of CpHly8 towards HA was 142.98 U/mg, with the optimum reaction temperature and pH observed at 50℃ and 6.0, respectively. The final product of HA degradation by CpHly8 was unsaturated hyaluronic acid disaccharide. Moreover, subcutaneous diffusion experiments with trypan blue in mice revealed that CpHly8 effectively promoted subcutaneous diffusion and sustained its effects long-term, suggesting its potential application as an adjunct in drug delivery. Overall, our study enriches our understanding of intestinal microbial degradation of HA, provides new evidence for horizontal gene transfer among intestinal microorganisms, and confirms that CpHly8 is a promising candidate for intestinal microbial hyaluronidase.

Identification and Characterization of a Highly Active Hyaluronan Lyase from Enterobacter asburiae

Hyaluronic acid (HA) is a well-known functional marine polysaccharide. The utilization and derivative development of HA are of great interest. Hyaluronan lyase has wide application prospects in the production of HA oligosaccharides and lower molecular weight HA. In this study, a strain of Enterobacter asburiae CGJ001 with high hyaluronan lyase activity was screened from industrial wastewater. This strain exhibited an impressive enzyme activity of 40,576 U/mL after being incubated for 14 h. Whole genome sequencing analysis revealed that E. asburiae CGJ001 contained a cluster of genes involved in HA degradation, transport, and metabolism. A newly identified enzyme responsible for glycosaminoglycan degradation was designated as HylEP0006. A strain of E. coli BL21(DE3)/pET-22b(+)-hylEP0006 was successfully constructed. HylEP0006 exhibited optimal degradation at 40 °C and pH 7.0, showing a high activity of 950,168.3 U/mg. HylEP0006 showed specific activity against HA. The minimum degradation fragment of HylEP0006 was hyaluronan tetrasaccharides, and HylEP0006 could efficiently degrade HA into unsaturated disaccharides (HA2), with HA2 as the final product. These characteristics indicate that HylEP0006 has a potential application prospect for the extraction and utilization of hyaluronic acid.

Evaluation of Therapeutic Efficiency of Stylicin against Vibrio parahaemolyticus Infection in Shrimp Penaeus vannamei through Comparative Proteomic Approach

The shrimp immune system defends and protects against infection by its naturally expressing antimicrobial peptides. Stylicin is a proline-rich anionic antimicrobial peptide (AMP) that exhibits potent antimicrobial activity. In this study, stylicin gene was isolated from Penaeus vannamei, cloned into vector pET-28a ( +), and overexpressed in Escherichia coli SHuffle T7 cells. The protein was purified and tested for its antibiofilm activity against shrimp pathogen Vibrio parahaemolyticus. It was resulted that the recombinant stylicin significantly reduced the biofilm formation of V. parahaemolyticus at a minimum inhibitory concentration (MIC) of 200 µg. Cell aggregation was observed by using scanning electron microscopy and confocal laser scanning microscopy, and it was resulted that stylicin administration significantly affects the cell structure and biofilm density of V. parahaemolyticus. In addition, real-time PCR confirmed the downregulation (p < 0.05) of genes responsible for growth and colonization. The efficacy of stylicin was tested by injecting it into shrimp challenged with V. parahaemolyticus and 7 days after infection, stylicin-treated animals recovered and survived better in both treatments (T2-100 µg stylicin, - 68.8%; T1-50 µg stylicin, 60%) than in control (7%) (p < 0.01). Comparative proteomic and mass spectrometry analysis of shrimp hemolymph resulted that the expressed proteins were involved in cell cycle, signal transduction, immune pathways, and stress-related proteins representing infection and recovery, and were significantly different in the stylicin-treated groups. The result of this study suggests that the stylicin can naturally boost immunity and can be used as a choice for treating V. parahaemolyticus infections in shrimp.

Cloning and Biochemical Characterization of a Hyaluronate Lyase from Bacillus sp. CQMU-D

Hyaluronidase (HAase) can enhance drug diffusion and dissipate edema by degrading hyaluronic acid (HA) in the extracellular matrix into unsaturated HA oligosaccharides in mammalian tissues. Microorganisms are recognized as valuable sources of HAase. In this study, a new hyaluronate lyase (HAaseD) from Bacillus sp. CQMU-D was expressed in Escherichia coli BL21, purified, and characterized. The results showed that HAaseD belonged to the polysaccharide lyase (PL) 8 family and had a molecular weight of 123 kDa. HAaseD could degrade chondroitin sulfate (CS) -A, CS-B, CS-C, and HA, with the highest activity toward HA. The optimum temperature and pH value of HAaseD were 40°C and 7.0, respectively. In addition, HAaseD retained stability in an alkaline environment and displayed higher activity with appropriate concentrations of metal ions. Moreover, HAaseD was an endolytic hyaluronate lyase that could degrade HA to produce unsaturated HA oligosaccharides. Together, our findings indicate that HAaseD from Bacillus sp. CQMU-D is a new hyaluronate lyase and with excellent potential for application in industrial production.

Enzymatic Production of Low-Molecular-Weight Hyaluronan and Its Oligosaccharides: A Review and Prospects

Hyaluronic acid (HA) is a nonsulfated linear glycosaminoglycan with a negative charge. Different from the high-molecular-weight HAs, the low-molecular-weight HAs (LMW-HAs, 4-120 kDa) and hyaluronan oligosaccharides (O-HAs, <4 kDa) exhibit certain unique biological properties, owing to which these have a wide range of applications in the field of medicine. However, the chemical synthesis of high-purity LMW-HAs and O-HAs requires complex procedures, which renders this process difficult to achieve. The degradation of HA is achieved under the catalysis of hyaluronidases. In recent years, various hyaluronidase genes have been identified, and their enzymatic properties have been analyzed. In this context, the present review summarizes the hyaluronidases from different sources, which have been characterized. The review focuses on the crystal structure and the catalytic mechanism underlying the biological properties of hyaluronidases. In addition, the molecular weight distributions and the preparation approaches of the enzymatic products LMW-HAs and O-HAs are described. The general orientation of the research on hyaluronidases was speculated based on the existing literature. Accordingly, the efficient large-scale production of LMW-HAs and O-HAs using the green enzymatic approach was anticipated.

YsHyl8A, an Alkalophilic Cold-Adapted Glycosaminoglycan Lyase Cloned from Pathogenic Yersinia sp. 298

A high enzyme-yield strain Yersinia sp. 298 was screened from marine bacteria harvested from the coastal water. The screening conditions were extensive, utilizing hyaluronic acid (HA)/chondroitin sulfate (CS) as the carbon source. A coding gene yshyl8A of the family 8 polysaccharide lyase (PL8) was cloned from the genome of Yersinia sp. 298 and subjected to recombinant expression. The specific activity of the recombinase YsHyl8A was 11.19 U/mg, with an optimal reaction temperature of 40 °C and 50% of its specific activity remaining after thermal incubation at 30 °C for 1 h. In addition, its optimal reaction pH was 7.5, and while it was most stable at pH 6.0 in Na2HPO4-citric acid buffer, it remained highly stable at pH 6.0–11.0. Further, its enzymatic activity was increased five-fold with 0.1 M NaCl. YsHyl8A, as an endo-lyase, can degrade both HA and CS, producing disaccharide end-products. These properties suggested that YsHyl8A possessed both significant alkalophilic and cold-adapted features while being dependent on NaCl, likely resulting from its marine source. Yersinia is a typical fish pathogen, with glycosaminoglycan lyase (GAG lyase) as a potential pathogenic factor, exhibiting strong hyaluronidase and chondroitinase activity. Further research on the pathogenic mechanism of GAG lyase may benefit the prevention and treatment of related diseases.

Hyaluronidases and hyaluronate lyases: From humans to bacteriophages

Hyaluronan is a non-sulfated negatively-charged linear polymer distributed in most parts of the human body, where it is located around cells in the extracellular matrix of connective tissues and plays an essential role in the organization of tissue architecture. Moreover, hyaluronan is involved in many biological processes and used in many clinical, cosmetic, pharmaceutic, and biotechnological applications worldwide. As interest in hyaluronan applications increases, so does interest in hyaluronidases and hyaluronate lyases, as these enzymes play a major part in hyaluronan degradation. Many hyaluronidases and hyaluronate lyases produced by eukaryotic cells, bacteria, and bacteriophages have so far been described and annotated, and their ability to cleave hyaluronan has been experimentally proven. These enzymes belong to several carbohydrate-active enzyme families, share very low sequence identity, and differ in their cleaving mechanisms and in their structural and functional properties. This review presents a summary of annotated and characterized hyaluronidases and hyaluronate lyases isolated from different sources belonging to distinct protein families, with a main focus on the binding and catalytic residues of the discussed enzymes in the context of their biochemical properties. In addition, the application potential of individual groups of hyaluronidases and hyaluronate lyases is evaluated.