Enzymatic properties of UFE,a novel marine fibrinolytic enzyme

A novel potent protease, Urechis unicinctus fibrinolytic enzyme （UFE）, was firstly discovered. The enzymatic properties of UFE were further investigated.As a low molecular mass protein,UFE appeared to be very stable to heat and pH.When temperature was below 50 ℃ ,the remnant enzyme activity remained almost unchanged, but when temperature was raised to 60 ℃ ,the remnant enzyme activity began to decrease rapidly. UFE was quite stable in the range of pH value from 3 to 12,especially in slightly alkaline pH value.Mn^2＋ ,Cu^2＋ and Fe^2＋ ions were activators of UFE, while Fe^3＋ and Ag^＋ ions were inhibitors of UFE.Fe^2＋ ion along with Fe^3＋ ion might regulate UFE activity in vivo. The optimum pH and temperature of UFE were about 8 and 50 ℃ ,respectively. Other characteristics of this enzyme were also studied. Systematic research results are significant when UFE is applied for medical and industrial purposes.

Marine-inspired molecular mimicry generates a drug-free, but immunogenic hydrogel adhesive protecting surgical anastomosis

Herein,we report the synthesis of a biomimic hydrogel adhesive that addresses the poor healing of surgical anastomosis.Dopamine-conjugated xanthan gum(Da-g-Xan)is fabricated using deep insights into the molecular similarity between mussels'adhesive and dopamine as well as the structural similarity between barnacle cement proteins and xanthan gum.The hydrogel mimics marine animals’adherence to wet tissue surfaces.Upon applying this adhesive to colonic anastomosis in a rat model,protective effects were shown by significantly improving the bursting pressure.Mechanistically,the architecture of Da-g-Xan hydrogel is maintained by dynamic intermolecular hydrogen bonds that allow the quick release of Da-g-Xan.The free Da-g-Xan can regulate the inflammatory status and induce type 2 macrophage polarization(M2)by specifically interacting with mannose receptors(CD206)revealed by RNA-sequencing and molecular binding assays.Consequently,an appropriate microenvironment for tissue healing is created by the secretion of chemokines and growth factors from M2 macrophages,strengthening the fibroblast migration and proliferation,collagen synthesis and epithelial vascularization.Overall,this study demonstrates an unprecedented strategy for generating an adhesive by synergistic mimicry inspired by two marine animals,and the results show that the Da-g-Xan adhesive augments native tissue regenerative responses,thus enabling enhanced recovery following surgical anastomosis.