Abstract:
:Antimicrobial peptides (AMPs) kill microbes by non-specific membrane permeabilization, making them ideal templates for designing novel peptide-based antibiotics that can combat multi-drug resistant pathogens. For maximum efficacy in vivo and in vitro, AMPs must be biocompatible, salt-tolerant and possess broad-spectrum antimicrobial activity. These attributes can be obtained by rational design of peptides guided by good understanding of peptide structure-function. Toward this end, this study investigates the influence of charge and hydrophobicity on the activity of tryptophan and arginine rich decamer peptides engineered from a salt resistant human β-defensin-28 variant. Mechanistic investigations of the decamers with detergents mimicking the composition of bacterial and mammalian membrane, reveal a correlation between improved antibacterial activity and the increase in tryptophan and positive residue content, while keeping hemolysis low. The potent antimicrobial activity and high cell membrane selective behavior of the two most active decamers, D5 and D6, are attributed to an optimum peptide charge to hydrophobic ratio bestowed by systematic arginine and tryptophan substitution. D5 and D6 show surface localization behavior with binding constants of 1.86 × 10(8) and 2.6 × 10(8) M(-1) , respectively, as determined by isothermal calorimetry measurements. NMR derived structures of D5 and D6 in SDS detergent micelles revealed proximity of Trp and Arg residues in an extended structural scaffold. Such potential cation-π interactions may be critical in cell permeabilization of the AMPs. The fundamental characterization of the engineered decamers provided in this study improves the understanding of structure-activity relationship of short arginine tryptophan rich AMPs, which will pave the way for future de novo design of potent AMPs for therapeutic and biomedical applications.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Saravanan R,Li X,Lim K,Mohanram H,Peng L,Mishra B,Basu A,Lee JM,Bhattacharjya S,Leong SSdoi
10.1002/bit.25003subject
Has Abstractpub_date
2014-01-01 00:00:00pages
37-49issue
1eissn
0006-3592issn
1097-0290journal_volume
111pub_type
杂志文章abstract::Highly efficient antibody immobilization is extremely crucial for the development of high-performance polymeric microdevices for enzyme-linked immunosorbent assay (ELISA). In this article, a site-selective tyrosinase (TR)-catalyzed protein A strategy for antibody immobilization was developed to enhance the sensitivity...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22136
更新日期:2009-02-15 00:00:00
abstract::One of the critical problems in scale-up of affinity chromatography is the mechanical strength of the support matrix against pressure. Because the costs of both the gel matrix and the ligand for the affinity chromatography are very high, the reusability of gel matrices is directly related to the total production cost....
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260391104
更新日期:1992-05-01 00:00:00
abstract::The simultaneous biodegradation of the nonionic surfactant Tween 20 (Tw20) and pentachlorophenol (PCP) by Sphingomonas chlorophenolica sp. Strain RA2 (RA2) was measured. As a sole substrate, Tw20 biodegradation was best described by the Contois kinetic model. During concurrent biodegradation of Tw20 and PCP, the biode...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20365
更新日期:2005-03-20 00:00:00
abstract::The application of enantioseparation methods alone can only yield up to 50% of the desired chiral product. Thus enantioseparation becomes more attractive when accompanied by the racemization of the counter-enantiomer. Here we present first results of dynamic kinetic resolution of L-asparagine (L-Asn) via preferential ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22498
更新日期:2009-12-15 00:00:00
abstract::A mechanistically detailed single-cell model E. coli B/r-A was adapted to simulate the effects of vector presence on cell metabolism. Competition for RNA polymerase between chromosome and plasmid DNA is explicitly included. Distribution of active ribosomes among chromosome- and plasmid-derived messenger RNA, another k...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260290305
更新日期:1987-02-01 00:00:00
abstract::Direct perfusion of 3D tissue engineered constructs is known to enhance osteogenesis, which can be partly attributed to enhanced nutrient and waste transport. In addition flow mediated shear stresses are known to upregulate osteogenic differentiation and mineralization. A quantification of the hydrodynamic environment...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22277
更新日期:2009-06-15 00:00:00
abstract::The thermo-responsive polymer poly(N-isopropylacrylamide) has received widespread attention for its in vitro application in the non-invasive, non-destructive release of adherent cells on two dimensional surfaces. In this study, 3D non-woven scaffolds fabricated from poly(propylene) (PP), poly(ethylene terephthalate) (...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24469
更新日期:2012-08-01 00:00:00
abstract::In large-scale mammalian cell culture, the key toxic by-products assessed and monitored are lactate and ammonia. Often no distinction between the two isoforms of lactate is made. Here, we present profiles of both D- and L-lactate. D-Lactate is the end molecule of the methylglyoxal pathway. D-Lactate unlike L-lactate i...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22757
更新日期:2010-09-01 00:00:00
abstract::Pancreatic islet transplantation is a promising alternative to whole-pancreas transplantation as a treatment of type 1 diabetes mellitus. This technique has been extensively developed during the past few years, with the main purpose of minimizing the complications arising from the standard protocols used in organ tran...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章,评审
doi:10.1002/bit.26821
更新日期:2018-12-01 00:00:00
abstract::Immunotherapy with ex vivo cultured T cells depends on a large supply of biologically active cells. Understanding the effects of culture parameters is essential for improving the proliferation and efficacy of the expanded cells. Low oxygen tension (5% pO(2)) was previously reported to improve T-cell expansion and alte...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20166
更新日期:2004-08-20 00:00:00
abstract::Pyruvate production by Torulopsis glabrata was used as a model to study the mechanism of product inhibition and the strategy for enhancing pyruvate production. It was found that the concentration of cell growth and pyruvate deceased with the increase of NaCl and sorbitol concentrations. To enhance the osmotic stress r...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21290
更新日期:2007-07-01 00:00:00
abstract::The production of ethanol from carob pod extract by free and immobilized Saccharomyces cerevisiae cells in batch and fed-batch culture was investigated. Fed-batch culture proved to be a better fermentation system for the production of ethanol than batch culture. In fed-batch culture, both free and immobilized S. cerev...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260430302
更新日期:1994-02-05 00:00:00
abstract::Although widely used in experimental and industrial situations, genetically engineered plasmids containing the lac promoter from Escherichia coli are subject to catabolite repression when grown in glucose-containing media. Several methods of overcoming this problem have been investigated by studying the expression of ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260380914
更新日期:1991-11-01 00:00:00
abstract::There has been much effort exerted to reduce one carbon (C1) gas emission to address climate change. As one promising way to more conveniently utilize C1 gas, several technologies have been developed to convert C1 gas into useful chemicals such as formic acid (FA). In this study, systems metabolic engineering was util...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26435
更新日期:2017-12-01 00:00:00
abstract::Ralstonia eutropha grows on and produces polyhydroxyalkanoates (PHAs) from fermentation acids. Acetic acid, one major organic acid from acidogenesis of organic wastes, has an inhibitory effect on the bacterium at slightly alkaline pH (6 g HAc/L at pH 8). The tolerance of R. eutropha to acetate, however, was increased ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.1080
更新日期:2001-06-20 00:00:00
abstract::We developed a method for the fast sorting and selection of mammalian cells expressing and secreting a protein at high levels. This procedure relies on cell capture using an automated microfluidic device handling antibody-coupled magnetic microparticles and on a timed release of the cells from the microparticles after...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26270
更新日期:2017-08-01 00:00:00
abstract::Adenoviruses are human pathogens increasingly used as gene therapy and vaccination vectors. However, their impact on cell metabolism is poorly characterized. We performed carbon labeling experiments with [1,2-13 C]glucose or [U-13 C]glutamine to evaluate metabolic alterations in the amniocyte-derived, E1-transformed 1...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26063
更新日期:2017-01-01 00:00:00
abstract::Biofouling is the undesirable adhesion and development of microorganisms and macroorganisms in a water environment. An electrochemical antifouling system based on management of primary adhesion of microorganisms was developed employing titanium electrode for antifouling of seawater cooling pipes and marine infrastruct...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21022
更新日期:2006-10-20 00:00:00
abstract::The mouse mammary tumor virus (MMTV) promoter is induced by the addition of a glucocorticoid hormone or analog such as dexamethasone. The hormone binds to its specific transcription factor, glucocorticoid receptor (GR), and the activated complex then binds to the glucocorticoid response elements (GREs) in the enhancer...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-01-20 00:00:00
abstract::The key objective for recombinant protein production in bacteria is the maximum exploitation of the cell factory's potential, whereby often strong expression vectors are used to increase product yield. If the metabolic load caused by recombinant expression exceeds the host's capacity, the system exhausts itself, resul...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10104
更新日期:2002-01-20 00:00:00
abstract::The hydrolysis of lactose by a beta-galactosidase from the thermophilic microorganism Thermus sp. strain T2, both in solution and immobilized on a commercial silica-alumina, has been studied. The enzyme has been previously produced by Escherichia coli JM101 harboring the plasmid pBGT1, which contains the codifying gen...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10466
更新日期:2003-01-20 00:00:00
abstract::Microplates with integrated optical oxygen sensors are a new tool to study metabolic rates and enzyme activities. Precise measurements are possible only if oxygen exchange between the sample and the environment is known. In this study we quantify gas exchange in plastic microplates. Dissolved oxygen was detected using...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20348
更新日期:2005-05-05 00:00:00
abstract::Enterokinase and recombinant enterokinase light chain (rEK(L)) have been used widely to cleave fusion proteins with the target sequence of (Asp)(4)-Lys. In this work, we show that their utility as a site-specific cleavage agent is compromised by sporadic cleavage at other sites, albeit at low levels. Further degradati...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10082
更新日期:2001-12-20 00:00:00
abstract::The effect of trehalose (0.5 M) on the thermal stability of cutinase in the alkaline pH range was studied. The thermal unfolding induced by increasing temperature was analyzed in the absence and in the presence of trehalose according to a two-state model (which assumes that only the folded and unfolded states of cutin...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20001220)70:6<699::aid-bit13>3.0
更新日期:2000-12-20 00:00:00
abstract::An experimental device was constructed to allow nearly simultaneous measurements to be made on temperature and gas composition at different depths in a solid-substrate fermentation bed. The time-dependent values of temperature, mol % O(2) and mol % CO(2) were measured at five positions in beds 6.35 cm (2.5 in.) deep. ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260250405
更新日期:1983-04-01 00:00:00
abstract::Nitrous oxide (N2 O), a potent greenhouse gas, is reduced to N2 gas by N2 O-reducing bacteria (N2 ORB), a process which represents an N2 O sink in natural and engineered ecosystems. The N2 O sink activity by N2 ORB depends on temperature and O2 exposure, yet the specifics are not yet understood. This study explores th...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.27654
更新日期:2020-12-11 00:00:00
abstract::A mixed culture of sulfate-reducing bacteria containing the species Desulfovibrio desulfuricans was used to study sulfate-reduction stoichiometry and kinetics using ethanol as the carbon source. Growth yield was lower, and kinetics were slower, for ethanol compared to lactate. Ethanol was converted into acetate and no...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:
更新日期:2000-12-05 00:00:00
abstract::In this study we describe a model that estimates the extracellular (nonfungal) and overall water contents of wheat grains during solid-state fermentation (SSF) with Aspergillus oryzae, using on-line measurements of oxygen, carbon dioxide, and water vapor in the gas phase. The model uses elemental balances to predict s...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/1097-0290(20000120)72:2<231::aid-bit11>3.0
更新日期:2001-01-20 00:00:00
abstract::A new ultrafiltration technique based on a multimembrane stack has been developed to fractionate solutes closer in size than conventionally possible. The technique is illustrated here by obtaining a pure protein product from a binary protein mixture. By employing membranes in series without any gaskets or spacers in-b...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20069
更新日期:2004-06-20 00:00:00
abstract::Streamline Direct CST I is a new type of ion exchanger with multi-modal functional groups, specially designed for an expanded bed adsorption (EBA) process, which can capture directly the proteins from the high ionic strength feedstocks with a high binding capacity. In this study, an experimental study is carried out f...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20952
更新日期:2006-08-20 00:00:00