Enzymatic Hydrolysis of Defatted Antheraea pernyi (Lepidoptera: Saturniidae) Pupa Protein by Combined Neutral Protease Yield Peptides With Antioxidant Activity

In this study, peptides were prepared from defatted Antheraea pernyi (Lepidoptera: Saturniidae) pupa protein via hydrolysis with combined neutral proteases. Single-factor tests and response surface methodology (RSM) were used to determine the optimal hydrolysis condition suitable for industrial application. Optimal hydrolysis of the defatted pupa protein was found to occur at an enzyme concentration of 4.85 g/liter, a substrate concentration of 41 g/liter, a hydrolysis temperature of 55°C, and a hydrolysis time of 10 h and 40 min. Under these conditions, the predicted and actual rates of hydrolysis were 45.82% and 45.75%, respectively. Peptides with a molecular weight of less than 2,000 Da accounted for 90.5% of the total peptides generated. Some of the peptides were antioxidant peptides as revealed by sequencing and functional analysis. The antioxidant activity of the mixed peptides was subsequently confirmed by an antioxidant activity assay. The results showed that peptides with high antioxidant activity could be obtained from the hydrolysis of A. pernyi pupa protein.

Enzymatic Bating Technology for Wet Blue

Most of the reported bating technologies for wet blue are based on the usage of acidic protease, which takes a long time and needs large enzyme dosage. A thorough understanding of the basic characteristics of typical acidic proteases and the interaction between enzyme proteins and wet blue fibers will help to improve bating technology for wet blue by selecting the suitable proteases. In this paper, the enzymatic characteristics, molecular weight (Mr) and isoelectric point (pI) of several proteases and their bating effectiveness were investigated. The results indicated that there are two main factors which may affect the wet blue bating effectiveness of acidic proteases. First, the common acidic proteases exhibited low activity towards chrome-tanned collagen fiber which lead to inefficient bating effect through normal dosage. Nonetheless, when the dosages of chrome-tanned collagen fiber activity reached up to 50 U/mL, these acidic proteases also can achieve a good bating effect, the caseinolytic activity has been reached up to 1000 U/mL-4000 U/mL. Second, because of the large molecular weight and the charge repulsion between enzyme proteins and wet blue fibers, the enzymatic hydrolysis process, the penetration and distribution of acidic protease proteins, into wet blue is very difficult. Additionally, neutral proteases have more prospects in wet blue bating process due to the higher chrome-tanned collagen fiber activity and less charge repulsion than acidic proteases.

HUMAN HEMATOPOIETIC STEM CELLS GENERATE EXOSOMES CONTAINING ACTIVE PROTEASOMES BUT NOT CASPASES

Activities of two classes of neutral proteases were studied: caspases and proteasomes, which are contained in extracellular vesicles generated by mesenchymal and hematopoietic human stem cells (MSCs and HSCs, respectively). The formation of apoptosomes induced by the cytochrome C and dATP did not occurred in these cells. The presence of TNFa in the culture medium of HSCs causes the appearance of caspase-3 intracellular activity. Herewith caspase activity was detected in exosomes also. This activity was completely inhibited by a non-substrate caspase inhibitor, emricasane, and it was not sensitive to proteasome inhibitors. It is assumed that the caspases’ activity from the cultural medium is the sum of membrane (outer side of exosome membrane), intracellular and extracellular activities. Apparently, this activity refers to apoptosomes as it was revealed by gel filtration of cultural medium with TNFa free from exosomes. Thus, TNFa induces the appearance of neutrophils in the culture of HSCs or the generation of other differentiated cells that are capable of apoptosis, in contrast to HSCs or MSCs. Proteasomal activity increased noticeably in exosomes from HSCs after the addition of TNFa. In contrast to exosomes from MSCs, all activity of proteasomes in HSCs-produced exosomes had a membrane localization.

EXTRACELLULAR PROTEASOMES

Little-known to a wide range of specialists details of the functioning of one of the main participants in cellular metabolism – a complex of neutral proteases with their regulators, which is called “proteasome” – are observed in this paper. The review analyzes the works of recent years devoted to the study of the participation of proteasomes in intercellular signaling and catabolism of regulatory and signaling proteins in the extracellular space.

Mast Cells in Inflammation and Disease: Recent Progress and Ongoing Concerns

Mast cells have existed long before the development of adaptive immunity, although they have been given different names. Thus, in the marine urochordate Styela plicata, they have been designated as test cells. However, based on their morphological characteristics (including prominent cytoplasmic granules) and mediator content (including heparin, histamine, and neutral proteases), test cells are thought to represent members of the lineage known in vertebrates as mast cells. So this lineage presumably had important functions that preceded the development of antibodies, including IgE. Yet mast cells are best known, in humans, as key sources of mediators responsible for acute allergic reactions, notably including anaphylaxis, a severe and potentially fatal IgE-dependent immediate hypersensitivity reaction to apparently harmless antigens, including many found in foods and medicines. In this review, we briefly describe the origins of tissue mast cells and outline evidence that these cells can have beneficial as well as detrimental functions, both innately and as participants in adaptive immune responses. We also discuss aspects of mast cell heterogeneity and comment on how the plasticity of this lineage may provide insight into its roles in health and disease. Finally, we consider some currently open questions that are yet unresolved.

Influence of the treatment used in inflammatory bowel disease on the level of protease activity

Introduction: There is growing evidence that intestinal proteases have a role in the pathogenesis of gastrointestinal inflammatory diseases. IBD, which includes Crohn's disease (CD) and ulcerative colitis (UC), has an additional source of proteases represented by infiltrated and activated inflammatory cells. The aim of our study was to determine proteolytic system activity in patients with CD and UC. We limited the number of proteases tested by determining proteases active in acidic, neutral and alkaline pH.Material and methods: The study included 40 patients with IBD – 20 CD patients and 20 UC patients. Among the 20 CD patients, 17 were treated with aminosalicylates, 14 with azathioprine, and 4 with corticosteroids, while 8 patients were undergoing biological treatment. Among the 20 UC patients, 19 were treated with aminosalicylates, 8 with azathioprine, and 3 with corticosteroids. The optimal pH in which the enzymes were active was determined in acidic, neutral, and alkaline buffer environments. We prepared buffers of defined pH from 2.2 to 12.8, separated by 0.2 intervals and then determined proteolytic activity against substrates (gelatine, haemoglobin, ovalbumin, albumin, cytochrome C, and casein). Results: A decrease was observed in the activity of acid proteases (pH 5), alkaline proteases (pH 7), and neutral proteases (pH 7.6 and 8.6) in the groups of CD patients in remission in comparison with the active phase. In the group of patients with CD treated biologically, acid protease activity (pH 5.0) was lower than in CD patients not receiving biological treatment.Activity of neutral (pH 7.0) and alkaline (pH 7.6 and 8.6) proteases in the plasma of patients with UC in remission were lower in comparison to the active phase.Activity of acid (pH 5.0) and alkaline (8.6) protease inhibitors was higher in CD patients in the active phase in comparison to remission. In UC patients with exacerbation of the disease, the activity of alkaline (pH 8.6) protease inhibitors was increased compared to remission.Conclusions: 1. Our research may suggest that the immunomodulatory treatment used in IBD, aimed at reducing the level of leukocytes, may contribute to a reduction in protease activity.2. The decrease in the level of proteases in patients with CD and UC in remission may be a marker suggesting the patients’ response to the treatment.

Engineering a recombination neutral protease I from Aspergillus oryzae to improve enzyme activity at acidic pH

Extracellular neutral proteases (NPs) in Aspergillus oryzae (A. oryzae) play a role in hydrolyzing soybean proteins into smaller peptides at pH about 7.5.