Bioprocess development to produce a hyperthermostable S-methyl-5'-thioadenosine phosphorylase in Escherichia coli.

Nucleoside phosphorylases are important biocatalysts for the chemo-enzymatic synthesis of nucleosides and their analogs which are, among others, used for the treatment of viral infections or cancer. S-methyl-5'-thioadenosine phosphorylases (MTAP) are a group of nucleoside phosphorylases and the thermostable MTAP of Aeropyrum pernix (ApMTAP) was described to accept a wide range of modified nucleosides as substrates. Therefore, it is an interesting biocatalyst for the synthesis of nucleoside analogs for industrial and therapeutic applications.

Optimization of Inclusion Body Formation and Purification in Multi-well Plates.

Heterologous expression has long been used for the efficient production of proteins and enzymes as it offers significant advantages over purification of proteins from their native organisms. When first established, great efforts have been made to heterologously express proteins with high yields in the soluble fraction, hence, avoiding protein aggregation. In recent decades, however, it has been shown that the formation of aggregates (inclusion bodies; IBs) can be beneficial.

A Comprehensive IT Infrastructure for an Enzymatic Product Development in a Digitalized Biotechnological Laboratory.

Typical product development in biotechnological laboratories is a distributed and versatile process. Today's biotechnological laboratory devices are usually equipped with multiple sensors and a variety of interfaces. The existing software for biotechnological research and development is often specialized on specific tasks and thus generates task-specific information.

Malnutrition Risk, Rurality, and Falls among Community-Dwelling Older Adults.

Objectives: We aimed to evaluate if malnutrition and rurality are associated with fall risk and future falls in community-dwelling older adults.

Design: Prospective Cohort.

Setting: Community, Vermont.

Corrigendum: Modular Enzymatic Cascade Synthesis of Nucleotides Using a (d)ATP Regeneration System.

[This corrects the article DOI: 10.3389/fbioe.2020.

Modular Enzymatic Cascade Synthesis of Nucleotides Using a (d)ATP Regeneration System.

Nucleoside-5'-triphosphates (NTPs) and their analogs are building blocks of DNA and are important compounds in both pharmaceutical and molecular biology applications. Currently, commercially available base or sugar modified NTPs are mainly synthesized chemically. Since the chemical production of NTPs is time-consuming and generally inefficient, alternative approaches are under development.

Entecavir plus tenofovir combination as rescue therapy in pre-treated chronic hepatitis B patients: an international multicenter cohort study.

Background & Aims: Long-term viral suppression is a major goal to prevent disease progression in patients with HBV. Aim of this study was to investigate the efficacy and safety of entecavir plus tenofovir combination in 57 CHB partial responders or multidrug resistant patients.

Methods: Investigator-initiated open-label cohort study.

[Animal experiment studies of development of anastomosis ulcers after reflux-inducing and reflux preventing stomach resection].

In an animal experiment the role of bile reflux in development of anastomotic ulcer after partial gastrectomy was investigated. On 45 pigs 2/3 partial gastrectomies and on 5 animals only laparotomies were carried out. The ulcer risk after reconstruction procedures with possible bile reflux was compared with reflux-free techniques.

Heterogeneity of insulin-like growth factor binding proteins in swine.

Proteins in porcine amniotic fluid and sera (both fetal and adult) were separated electrophoretically in sodium dodecyl sulfate-containing polyacrylamide gels and transferred to nitrocellulose sheets. Western blots were analysed for proteins that would bind (a) radioiodinated insulin-like growth factor-I (IGF-I) and (b) antibodies to a rat insulin-like growth factor binding protein. Multiple insulin-like growth factor binding proteins were identified in sera.

Calpain II involvement in mitosis.

Mitotic spindle disassembly requires major structural alterations in the associated cytoskeletal proteins and mitosis is known to be associated with Ca2+-sequestering phenomena and calcium transients. To examine the possible involvement of a ubiquitous Ca2+-activated protease, calpain II, in the mitotic process, synchronized PtK1 cells were monitored by immunofluorescence for the relocation of calpain II. The plasma membrane was the predominant location of calpain II in interphase.

Effect of post-mortem storage on Ca(++)-dependent proteases, their inhibitor and myofibril fragmentation.

Post-mortem changes in two calcium-dependent proteases, their inhibitor, myofibril fragmentation index (MFI) and collagen (amount and solubility) were studied. Whereas the activity of high Ca(++)-requiring calcium-dependent protease (CDP-II) remained nearly constant throughout post-mortem storage, there was a progressive decrease in the activities of low Ca(++)-requiring calcium-dependent protease (CDP-I) and their specific inhibitor, with the inhibitor being the most susceptible to post-mortem storage. Results indicated that the greatest changes in MFI occur within the first 24 h of post-mortem storage.

The reversible inhibition of myoblast proliferation by gamma-hexachlorocyclohexane.

The effects of treating non-fusing myoblast variants, fu-1 and M3A, with two levels (1 X 10(-4) M and 2 X 10(-4) M) of gamma-hexachlorocyclohexane, an inhibitor of phosphatidylinositol synthesis, on myoblast proliferation were evaluated by measuring myoblast proliferation (counting cells) and visual inspection via phase microscopy. In the presence of gamma-hexachlorocyclohexane, these cells were arrested, presumably in G1. The inability of these cells to replicate did not appear to be due to a toxic effect of gamma-hexachlorocyclohexane, because these cells were capable of resuming proliferation once they were transferred to media lacking gamma-hexachlorocyclohexane.

Identification of calpain II in porcine sperm.

The role that proteolytic enzymes may play in membrane-associated phenomena of sperm has been the subject of extensive investigation. In the present study, we have examined the possibility that a Ca2+-activated, neutral protease, calpain II, may be associated with sperm membranes. Using indirect immunofluorescence with primary antibodies, which are polyclonal and monoclonal antibodies directed against the 80 kDa subunit of calpain II, we have established the presence of this antigen in porcine sperm.

Possible role of calpain I and calpain II in differentiating muscle.

The variable distribution of the 80-kD subunit of two calcium-activated proteases, calpain I and calpain II, has been examined in L8 and L6 myoblasts, and their non-fusing variants, fu-1 and M3A using non-cross-reacting monoclonal antibodies to both subunits. Immunofluorescence results have shown that while the 80-kD subunit of calpain I is localized in the cytoplasm of all the myoblasts, the 80-kD subunit of calpain II appears to be predominantly associated with the plasma membranes of L8 and L6 myoblasts. The distribution of the 80-kD subunit of calpain II in non-fusing myoblasts, fu-1 and M3A, is generally cytoplasmic and diffuse.

Role of Ca2+ and Ca2+-activated protease in myoblast fusion.

In this report, we have examined the effects of a calcium chelator, EGTA, and a calcium ionophore, A23187, on fusion of a cloned muscle cell line, L6. Our results confirm that EGTA essentially blocks all myoblast fusion because the lateral alignment of presumptive myoblasts cannot occur in the absence of extracellular calcium. A23187, however, promotes the precocious fusion of myoblasts, apparently by facilitating Ca2+ transport into myoblasts.

Effects of electrical stimulation on post-mortem changes in the activities of two Ca dependent neutral proteinases and their inhibitor in beef muscle.

Post-mortem changes in the activities of two calcium-dependent neutral proteinases and their inhibitor were studied in electrically stimulated and control beef Longissimus dorsi muscles. During meat conditioning in control muscles the activity of the high-calcium-requiring proteinase (mmCa ANP) was not affected while a decrease in the activities of the low-calcium-requiring proteinase (μmCa ANP) was observed. After electrical stimulation, the mmCa ANP activity was only slightly decreased, but the μmCa ANP and the inhibitor activities were drastically affected.

Distribution of memantine in brain, liver, and blood of the rat.

The distribution of 1,3-dimethyl-5-aminoadamantane (DMAA, D-145, memantine, Memantine), a compound used in the treatment of CNS disorders, is investigated in liver, brain, and blood of the rat. The tissue concentration of memantine is analyzed by gaschromatography after i.p.

A calcium-activated protease possibly involved in myofibrillar protein turnover. Isolation of a low-calcium-requiring form of the protease.

Two forms of calcium-activated neutral protease were isolated and purified from porcine skeletal muscle. The two forms of the protease differ markedly in their requirement for calcium with the low-calcium-requiring form showing one-half maximal activation at 45 micro M calcium while the high-calcium-requiring form shows one-half maximal activation at 0.74 micro M calcium.

Immunohistochemical localization of actin: applications in surgical pathology.

The contractile protein actin was demonstrated in formalin-fixed and paraffin-embedded human tissue by the peroxidase-antiperoxidase method of Sternberger. Both types of muscular cells and some other cell types showed positive staining. In skeletal muscle, the staining was seen diffusely in the cytoplasm with accentuation of cross-striations (I-bands).

Morphological revertants of an avian sarcoma virus-transformed mammalian cell line exhibit tumorigenicity and contain pp60src.

The biological and biochemical properties of Rous sarcoma virus-transformed and revertant field vole cells were investigated. Revertant vole cells appear morphologically similar to normal, uninfected cells, yet, like transformed vole cells, they are fully capable of growing in agar suspension and producing tumors in athymic nude mice. These highly tumorigenic, yet morphologically normal appearing, vole cells express viral-specific antigens such as the gag gene product (Pr76) but lack the env gene protein (gp85).

Elevated levels of a calcium-activated muscle protease in rapidly atrophying muscles from vitamin E-deficient rabbits.

A Ca2+-activated proteolytic enzyme that partially degrades myofibrils was isolated from hind limb muscles of normal rabbits and rabbits undergoing rapid muscle atrophy as a result of vitamin E deficiency. Extractable Ca2+-activated protease activity was 3.6 times higher in muscle tissue from vitamin E-deficient rabbits than from muscle tissue of control rabbits.

alpha-Actinin deficiency in thrombasthenia: possible identity of alpha-actinin and glycoprotein III.

Blood platelets contain a variety of contractile protein species, including the glycoprotein alpha-actinin, which is found at the Z disc in skeletal muscle cells. In the present study, we have considered the possibility that alpha-actinin might be one of several previously described platelet surface glycoproteins. Purified anti-alpha-actinin antibody was found to react strongly with partially purified platelet glycoprotein III, weakly with platelet glycoprotein IIb, and not at all with platelet glycoproteins Ib and IV.