Conservative Tryptophan Residue in the Vicinity of an Active Site of the M15 Family l,d-Peptidases: A Key Element in the Catalysis.

Bioinformatics analysis of the sequences of orthologous zinc-containing peptidases of the M15_C subfamily revealed the presence of a conserved tryptophan residue near the active site, which is not involved in the formation of the protein core. Site-directed mutagenesis of this Trp114/109 residue using two representatives of the family, l-alanoyl-d-glutamate peptidases of bacteriophages T5 (calcium-activated EndoT5) and RB49 (EndoRB49, without ion regulation) as examples, and further analysis of the H NMR spectra of the mutants showed that a decrease in the volume of the W → F → A residue leads to changes in the hydrophobic core and active center of the protein, and also decreases the affinity for regulatory Ca in the EndoT5 mutants. The inactive T5W114A mutant lacks the ability to bind the substrate.

Arterial and retinal vascular changes in hypertensive and prehypertensive adolescents.

Introduction: Increasing evidence suggests that arterial hypertension (AHT) may begin in childhood and result in the premature development of cardiovascular disease. In view of this, we believed it would be important to investigate the early vascular changes related to early hypertension at the micro- and macrovascular levels both under normal circumstances and after cold-induced sympathetic stimulation.

Methods: In a cohort of 121 adolescent subjects, we measured peripheral and central blood pressure (pBP and cBP, respectively), pulse pressure (PP), and the augmentation index (AIx), as well as retinal vascular diameters, at baseline and during a cold pressor test (CPT).

Dynamic retinal vessel response to flicker in obesity: A methodological approach.

Obesity and related metabolic disorders affect vascular endothelial function. The use of the Dynamic Vessel Analyzer (DVA) represents a modern methodological approach to analyze vascular function in the retinal microcirculation. Whether the dynamic reaction to flicker stimulation in retinal vessels is altered in obese subjects is investigated.

[A case of inadequate surgery tactics in the use of an unstandard orbital implant].

By analyzing a clinical case with inadequate surgery tactics in the use of an unstandard orbital implant, the authors discuss possible errors in surgical techniques and in the choice of an implant. Furthermore, by analyzing problems in the use of various implants, including those unstandard ones, they discuss possible causes of complications, consider the optimal time for resurgeries, and propose the ways of solving the problems associated with the occurrence of complications, including treatment policy.