An artificial self-assembling peptide with carboxylesterase activity and substrate specificity restricted to short-chain acid p-nitrophenyl esters.

Natural enzymes possess remarkable catalytic activity and high substrate specificity. Many efforts have been dedicated to construct artificial enzymes with high catalytic activity. However, how to mimic the exquisite substrate specificity of a natural enzyme remains challenging because of the complexity of the enzyme structure. Here, we report artificial carboxylesterases that are specific for short chain fatty acids and were constructed via peptide self-assembly. These artificial systems have esterase-like activity rather than lipase-like activity towards p-nitrophenyl esters. The designer peptides self-assembled into nanofibers with strong ß-sheet character. The extending histidine units and the hydrophobic edge of the fibrillar structure collectively form the active center of the artificial esterase. These artificial esterases show substrate specificity for short-chain acids esters. Moreover, 1-isopropoxy-4-nitrobenzene could function as a competitive inhibitor of hydrolysis of p-nitrophenyl acetate for an artificial esterase.

Effect of Y-27632 on the cultured retinal neurocytes of rats.

AIM: To investigate the effect of Y-27632 on the survival and neurite outgrowth of the cultured retinal neurocytes. METHODS: After the postnatal day 2-3, Sprague-Dawley retinal neurocytes were cultured for 48 hours, the culture media was replaced with serum-free media (control group) and serum-free media contained 30µmol/L Y-27632 (Y-27632 group), and the cells were continually cultured another 48 hours. The cultured retinal neurocytes were identified with anti-neuron specific enolase (NSE) immunocytochemistry. The survival state of those cells was estimated by MTT assay, and the neurite outgrowth of those cells was evaluated by the computerized image-analysis system. RESULTS: Compared with the control group, the absorbance values of cells survival in Y-27632 group increased 12.90% and 33.33% respectively after 72 and 96 hours culture. Y-27632 had no significant effect on the diameter of cultured retinal neurocytes. Compared with the control group, Y-27632 induced a stable improvement of neurite outgrowth of retinal neurocytes after 72 and 96 hours culture (P=0.001). CONCLUSION: Y-27632 could promote the survival and neurite outgrowth of the early postnatal cultured retinal neurocytes.

Trabeculectomy in the management of glaucomatocyclitic crisis with visual field defect.

PURPOSE: To investigate the effect of trabeculectomy in the management of glaucomatocyclitic crisis with uncontrolled intraocular pressures (IOPs) and visual field defects. METHODS: Trabeculectomy was performed in 8 patients (2 males and 6 females) who had unilateral glaucomatocyclitic crisis with uncontrolled intraocular pressure (IOP) and visual field defects. After the surgeries the patients were followed up for 30.00 +/- 17.24 (mean +/- SD, the same below) months with best-corrected visual acuity (BCVA) and IOP measurements, keratic precipitates (KP), bleb and anterior chamber exams, and visual field tests. RESULTS: Preoperative IOP of these patients was 50.13 +/- 4.58 mmHg. By the end of follow-up, IOP in all patients was reduced to normal level (14.63 +/- 2.33 mmHg) without any anti-glaucoma medications. Three patients had type I blebs, and 5 patients had type II blebs. Six patients had no recurrent attacks during the entire follow-up period, while recurrent anterior uveitis was observed in the other 2 patients (2 and 3 times, respectively). No visual acuity loss or further visual field loss was found in any of these patients at the end of follow-up. CONCLUSIONS: Trabeculectomy is a safe and effective method for the management of glaucomatocyclitic crisis with uncontrolled IOPs and visual field defects.