Bowman-Birk Inhibitors: Insights into Family of Multifunctional Proteins and Peptides with Potential Therapeutical Applications

Bowman-Birk inhibitors (BBIs) are found primarily in seeds of legumes and in cereal grains. These canonical inhibitors share a highly conserved nine-amino acids binding loop motif CTP1SXPPXC (where P1 is the inhibitory active site, while X stands for various amino acids). They are natural controllers of plants’ endogenous proteases, but they are also inhibitors of exogenous proteases present in microbials and insects. They are considered as plants’ protective agents, as their elevated levels are observed during injury, presence of pathogens, or abiotic stress, i.a. Similar properties are observed for peptides isolated from amphibians’ skin containing 11-amino acids disulfide-bridged loop CWTP1SXPPXPC. They are classified as Bowman-Birk like trypsin inhibitors (BBLTIs). These inhibitors are resistant to proteolysis and not toxic, and they are reported to be beneficial in the treatment of various pathological states. In this review, we summarize up-to-date research results regarding BBIs’ and BBLTIs’ inhibitory activity, immunomodulatory and anti-inflammatory activity, antimicrobial and insecticidal strength, as well as chemopreventive properties

LIPID ACCUMULATION OF CHLORELLA VULGARIS UNDER DIFFERENT PHOSPHATE CONCENTRATIONS

The cultivation and utilization of microalgae is now a intensively developing area of research. Some species of microalgae, under appropriate conditions, accumulate large amounts of lipids in the cells. This lipids have a suitable profile of fatty acids for biodiesel production. The culture of microalgae for lipids accumulation should be performed in certain physicochemical conditions. The aim of the study was to determine the effect of variable ortophophates concentrations in the culture medium for lipids accumulation of microalgae Chlorella vulgaris and to determine of parameters of the phosphoric shock in the medium. The study confirmed the possibility of the use of the phosphoric shock in the medium to maximize lipids accumulation by the microalgae Chlorella vulgaris. In the study, 45.23% of the oil was obtained from the biomass from the culture with phosphoric shock in the medium and 18% less of the oil was obtained from the biomass from the standard culture

IMPACT OF ATHERMIC PROPERTIES OF THE ELECTROMAGNETIC MICROWAVE RADIATION ON THE PROCESS OF ANAEROBIC DIGESTION OF DAIRY WASTEWATER

The aim of this study was to determine the effect of electromagnetic microwave radiation on the activity of microorganisms during the anaerobic digestion of dairy wastewater. The substrate used in the study was a model dairy wastewater prepared with the use of milk powder. The anaerobic sludge was taken from the anaerobic reactor operated at mesophilic conditions, then it was heated by microwave irradiation (Option 1) or heated in a conventional thermostatic cabinet (Option 2). The study, based on the temperature of the process, was divided into two stages. In the first stage, the temperature of the process was 38°C and in the second stage it was 58°C. The studies showed that the use of microwave electromagnetic field might influence on the biogas production. Furthermore, microwave treatment of anaerobic sludge enhanced the removal of organic compounds in the methane fermentation process

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed

Synthesis of Novel Arginine Building Blocks with Increased Lipophilicity Compatible with Solid-Phase Peptide Synthesis

Arginine, due to the guanidine moiety, increases peptides’ hydrophilicity and enables interactions with charged molecules, but at the same time, its presence in a peptide chain might reduce its permeability through biological membranes. This might be resolved by temporary coverage of the peptide charge by lipophilic, enzyme-sensitive alkoxycarbonyl groups. Unfortunately, such a modification of a guanidine moiety has not been reported to date and turned out to be challenging. Here, we present a new, optimized strategy to obtain arginine building blocks with increased lipophilicity that were successfully utilized in the solid-phase peptide synthesis of novel arginine vasopressin prodrugs

Like other canonical inhibitors, SFTI-1 interacts with a cognate enzyme (i.e. with trypsin) <i>via</i> its solvent-exposed binding loop between Cys³ and Cys¹¹.

<p>The central peptide bond between Lys⁵ (P₁) and Ser⁶ (P₁′) is known as a reactive site <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089465#pone.0089465-Luckett1" target="_blank">[17]</a>. The adjacent residues placed on the left side of this bond are marked with non-prime P (P₂, P₃, … P_n etc), whereas, on the right side, with prime P (P₂′, P₃′, … P_n etc) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089465#pone.0089465-Schechter1" target="_blank">[18]</a>. Corresponding enzyme substrate binding pockets are called non-prime (S₁, S₂, S₃, …, S_n) and prime (S₁′, S₂′, S₃′, …,S_n′) sites, respectively.</p

Assays in 50m Tris-HCl buffer without SDS (A) analogue V; (B) analogue IX.

<p>Both peptides stimulate ChT-L activity of latent yeast 20S proteasome; [E] = 0.9 nm; [Suc-LLVY-AMC] = 5.2 µm; incubation time 30 min. at 37°C. Data for analogue III are not presented.</p

Inhibition of chymotrypsin-like (ChT-L) and caspase-like (C–L) activities of SDS-activated human 20S ([E] = 2.7 nm) by BPTI and Z-LLL-CHO (A).

<p>Inhibition of trypsin-like (T-L) activity of latent human 20S ([E] = 2.7 nm) (<b>B</b>). Incubation time was about 30 min. at 37°C.</p

The rate of substrate Suc-LLVY-AMC hydrolysis (a release of AMC molecule) with control and inhibitor V- treated human 20S versus the substrate concentration (A), the enzyme concentration was kept constant at 2.7 nm; the double reciprocal Lineweaver-Burk plot (B).

<p>The rate of substrate Suc-LLVY-AMC hydrolysis (a release of AMC molecule) with control and inhibitor V- treated human 20S versus the substrate concentration (A), the enzyme concentration was kept constant at 2.7 nm; the double reciprocal Lineweaver-Burk plot (B).</p