Search results for "protein engineering"
showing 10 items of 54 documents
Engineered Trx2p industrial yeast strain protects glycolysis and fermentation proteins from oxidative carbonylation during biomass propagation
2012
Abstract Background In the yeast biomass production process, protein carbonylation has severe adverse effects since it diminishes biomass yield and profitability of industrial production plants. However, this significant detriment of yeast performance can be alleviated by increasing thioredoxins levels. Thioredoxins are important antioxidant defenses implicated in many functions in cells, and their primordial functions include scavenging of reactive oxygen species that produce dramatic and irreversible alterations such as protein carbonylation. Results In this work we have found several proteins specifically protected by yeast Thioredoxin 2 (Trx2p). Bidimensional electrophoresis and carbony…
Engineering of chicken avidin: a progressive series of reduced charge mutants.
1998
Avidin, a positively charged egg-white glycoprotein, is a widely used tool in biotechnological applications because of its ability to bind biotin strongly. The high pI of avidin (approximately 10.5), however, is a hindrance in certain applications due to non-specific (charge-related) binding. Here we report a construction of a series of avidin charge mutants with pIs ranging from 9.4 to 4.7. Rational design of the avidin mutants was based on known crystallographic data together with comparative sequence alignment of avidin, streptavidin and a set of avidin-related genes which occur in the chicken genome. All charge mutants retained the ability to bind biotin tightly according to optical bio…
Recombinant NeutraLite Avidin: a non-glycosylated, acidic mutant of chicken avidin that exhibits high affinity for biotin and low non-specific bindin…
2000
AbstractA recombinant non-glycosylated and acidic form of avidin was designed and expressed in soluble form in baculovirus-infected insect cells. The mutations were based on the same principles that guided the design of the chemically and enzymatically modified avidin derivative, known as NeutraLite Avidin. In this novel recombinant avidin derivative, five out of the eight arginine residues were replaced with neutral amino acids, and two of the lysine residues were replaced by glutamic acid. In addition, the carbohydrate-bearing asparagine-17 residue was altered to an isoleucine, according to the known sequences of avidin-related genes. The resultant mutant protein, termed recombinant Neutr…
Recombinant avidin and avidin-fusion proteins.
2000
Both chicken egg-white avidin and its bacterial relative streptavidin are well known for their extraordinary high affinity with biotin (Kd approximately 10(-15) M). They are widely used as tools in a number of affinity-based separations, in diagnostic assays and in a variety of other applications. These methods have collectively become known as (strept)avidin-biotin technology. Biotin can easily and effectively be attached to different molecules, termed binders and probes, without destroying their biological activity. The exceptional stability of the avidin-biotin complex and the wide range of commercially available reagents explain the popularity of this system. In order by genetic enginee…
Engineering Proteins at Interfaces: From Complementary Characterization to Material Surfaces with Designed Functions
2018
Abstract Once materials come into contact with a biological fluid containing proteins, proteins are generally—whether desired or not—attracted by the material's surface and adsorb onto it. The aim of this Review is to give an overview of the most commonly used characterization methods employed to gain a better understanding of the adsorption processes on either planar or curved surfaces. We continue to illustrate the benefit of combining different methods to different surface geometries of the material. The thus obtained insight ideally paves the way for engineering functional materials that interact with proteins in a predetermined manner.
Biomimetic composites with enhanced toughening using silk-inspired triblock proteins and aligned nanocellulose reinforcements
2019
Silk-like proteins produced in bacteria are used as adhesives for cellulose nanofibrils to make a new biological material.
Structure-based engineering of strictosidine synthase: auxiliary for alkaloid libraries.
2007
SummaryThe highly substrate-specific strictosidine synthase (EC 4.3.3.2) catalyzes the biological Pictet-Spengler condensation between tryptamine and secologanin, leading to the synthesis of about 2000 monoterpenoid indole alkaloids in higher plants. The crystal structure of Rauvolfia serpentina strictosidine synthase (STR1) in complex with strictosidine has been elucidated here, allowing the rational site-directed mutation of the active center of STR1 and resulting in modulation of its substrate acceptance. Here, we report on the rational redesign of STR1 by generation of a Val208Ala mutant, further describing the influence on substrate acceptance and the enzyme-catalyzed synthesis of 10-m…
Expression and purification of polyhistidine-tagged firefly luciferase in insect cells
2001
The coleopteran firefly, Photinus pyralis, luciferase was produced in lepidopteran Trichoplusia ni insect cells using a baculovirus expression vector. The recombinant protein was equipped with a polyhistidine affinity tag at the carboxyl terminus and purified by immobilized metal-ion affinity chromatography in combination with an expanded bed adsorption system. This approach enabled an efficient, one-step purification protocol of a genetically modified luciferase with properties similar to those of the authentic counterpart. According to light emission measurements, the final yield of highly purified protein was 23 mg l−1 of cell culture. In addition, no specific interaction of interfering …
High Resolution Solution NMR Structure of the Z Domain of Staphylococcal Protein A. Analysis of Secondary Structure for Free Z Domain and Bounded to …
1997
Staphylococcal protein A (SpA) is a cell-wall-bound pathogenicity factor from the bacterium Staphylcoccus aureus. It exhibits tight binding to many IgG, IgA and IgM molecules at site(s) different from antigen-combining site. Because of their small size and immunoglobulin (IgG)-binding activities, domains of protein A are important targets for protein engineering efforts and for the development of computational approaches for de novo protein folding.
Analysis of Structure-Activity Relationships of the Bowman-Birk Inhibitor of Serine Proteinases
1993
Proteinase inhibitors are a class of the various dietary inhibitors of mutagenesis and carcinogenesis (Hayatsu et al., 1988). Schelp and Pongpaew (1988) have recently hypothesized that protection against cancer may result from an increase of endogenous proteinase inhibitors such as α2-macroglobulin induced by diets that are low in calories and fat. The Bowman-Birk inhibitor (BBI) of serine proteinases, a double-headed polypeptide-inhibitor of trypsin and chymotrypsin, is one of the most potent cancer chemopreventive agents (Yavelow et al., 1983, 1985). Recently, this property has been substantiated in an in vivo investigation using mice (St. Clair et al., 1990) that were exposed to dimethyl…