Amino Acids (v.50, #7)

Atomic displacement parameters (ADPs, also known as B-factors), which depend on structural heterogeneity, provide a wide spectrum of information on protein structure and dynamics and find several applications, from protein conformational disorder prediction to protein thermostabilization, and from protein folding kinetics prediction to protein binding sites prediction. A crucial aspect is the standardization of the ADPs when comparisons between two or more protein crystal structures are made, since ADPs are differently affected by several factors, from crystallographic resolution to refinement protocols. A potential limitation to ADP analysis is the modern tendency to let ADPs to inflate up to extremely large values that have little physico-chemical meaning.
Keywords: Atomic displacement parameter; B-factor; Crystallography; Protein flexibility; Protein structure; Structural bioinformatics

Zebrafish heart failure models: opportunities and challenges by Xingjuan Shi; Ru Chen; Yu Zhang; Junghwa Yun; Koroboshka Brand-Arzamendi; Xiangdong Liu; Xiao-Yan Wen (787-798).
Heart failure is a complex pathophysiological syndrome of pumping functional failure that results from injury, infection or toxin-induced damage on the myocardium, as well as genetic influence. Gene mutations associated with cardiomyopathies can lead to various pathologies of heart failure. In recent years, zebrafish, Danio rerio, has emerged as an excellent model to study human cardiovascular diseases such as congenital heart defects, cardiomyopathy, and preclinical development of drugs targeting these diseases. In this review, we will first summarize zebrafish genetic models of heart failure arose from cardiomyopathy, which is caused by mutations in sarcomere, calcium or mitochondrial-associated genes. Moreover, we outline zebrafish heart failure models triggered by chemical compounds. Elucidation of these models will improve the understanding of the mechanism of pathogenesis and provide potential targets for novel therapies.
Keywords: Heart failure; Cardiomyopathy; Zebrafish; Sarcomere; Mitochondria; Chemical compound

Results, meta-analysis and a first evaluation of UNOxR, the urinary nitrate-to-nitrite molar ratio, as a measure of nitrite reabsorption in experimental and clinical settings by Dimitrios Tsikas; Erik Hanff; Alexander Bollenbach; Ruan Kruger; Vu Vi Pham; Kristine Chobanyan-Jürgens; Dirk Wedekind; Tanja Arndt; Anne Jörns; Jimmy F. P. Berbée; Hans M. G. Princen; Thomas Lücke; François Mariotti; Jean-François Huneau; Stefan Ückert; Jürgen C. Frölich; Sigurd Lenzen (799-821).
We recently found that renal carbonic anhydrase (CA) is involved in the reabsorption of inorganic nitrite (NO2 ), an abundant reservoir of nitric oxide (NO) in tissues and cells. Impaired NO synthesis in the endothelium and decreased NO bioavailability in the circulation are considered major contributors to the development and progression of renal and cardiovascular diseases in different conditions including diabetes. Isolated human and bovine erythrocytic CAII and CAIV can convert nitrite to nitrous acid (HONO) and its anhydride N2O3 which, in the presence of thiols (RSH), are further converted to S-nitrosothiols (RSNO) and NO. Thus, CA may be responsible both for the homeostasis of nitrite and for its bioactivation to RSNO/NO. We hypothesized that enhanced excretion of nitrite in the urine may contribute to NO-related dysfunctions in the renal and cardiovascular systems, and proposed the urinary nitrate-to-nitrite molar ratio, i.e., UNOxR, as a measure of renal CA-dependent excretion of nitrite. Based on results from clinical and experimental animal studies, here, we report on a first evaluation of UNOxR. We determined UNOxR values in preterm neonates, healthy children, and adults, in children suffering from type 1 diabetes mellitus (T1DM) or Duchenne muscular dystrophy (DMD), in elderly subjects suffering from chronic rheumatic diseases, type 2 diabetes mellitus (T2DM), coronary artery disease (CAD), or peripheral arterial occlusive disease (PAOD). We also determined UNOxR values in healthy young men who ingested isosorbide dinitrate (ISDN), pentaerythrityl tetranitrate (PETN), or inorganic nitrate. In addition, we tested the utility of UNOxR in two animal models, i.e., the LEW.1AR1-iddm rat, an animal model of human T1DM, and the APOE*3-Leiden.CETP mice, a model of human dyslipidemia. Mean UNOxR values were lower in adult patients with rheumatic diseases (187) and in T2DM patients of the DALI study (74) as compared to healthy elderly adults (660) and healthy young men (1500). The intra- and inter-variabilities of UNOxR were of the order of 50% in young and elderly healthy subjects. UNOxR values were lower in black compared to white boys (314 vs. 483, P = 0.007), which is in line with reported lower NO bioavailability in black ethnicity. Mean UNOxR values were lower in DMD (424) compared to healthy (730) children, but they were higher in T1DM children (1192). ISDN (3 × 30 mg) decreased stronger UNOxR compared to PETN (3 × 80 mg) after 1 day (P = 0.046) and after 5 days (P = 0.0016) of oral administration of therapeutically equivalent doses. In healthy young men who ingested NaNO3 (0.1 mmol/kg/d), UNOxR was higher than in those who ingested the same dose of NaCl (1709 vs. 369). In LEW.1AR1-iddm rats, mean UNOxR values were lower than in healthy rats (198 vs. 308) and comparable to those in APOE*3-Leiden.CETP mice (151).
Keywords: Diabetes; Drugs; Health; Mass spectrometry; Nitric oxide reservoir; Renal carbonic anhydrase; Rheumatic disease

Method for electrochemical determination of l-tyrosine with screen-printed electrodes (SPE) modified with multi-walled CNT or CNT/TiO2 as sensing elements was used for the electroanalysis of l-tyrosine (Tyr). It was demonstrated that SPE/CNT and SPE/CNT/TiO2 exhibited high electrocatalytic activity and good analytical performance towards oxidation of l-tyrosine. The linear range of Tyr in human serum was 0.025 ÷ 1 mM with the correlation coefficient R 2 = 0.97. Direct electrochemistry (without any mediator) of co-factor-free bovine serum albumin (BSA) and human serum albumin (HSA) was investigated by use of modified electrodes. Protein–ligand interactions based on the electrocatalytic oxidation of l-tyrosine during HSA interaction with hemin were analyzed by the change of peak height and oxidation peak area, corresponding to tyrosine oxidation accessibility.
Keywords: l-Tyrosine; Electrocatalytic oxidation; TiO2 ; Protein electrochemistry; Multi-walled carbon nanotubes; Modified electrodes

The effects of acute leucine or leucine–glutamine co-ingestion on recovery from eccentrically biased exercise by Mark Waldron; Cameron Ralph; Owen Jeffries; Jamie Tallent; Nicola Theis; Stephen David Patterson (831-839).
This study investigated the effects of leucine or leucine + glutamine supplementation on recovery from eccentric exercise. In a double-blind independent groups design, 23 men were randomly assigned to a leucine (0.087 g/kg; n = 8), leucine + glutamine (0.087 g/kg + glutamine 0.3 g/kg; n = 8) or placebo (0.3 g/kg maltodextrin; n = 7) group. Participants performed 5 sets of drop jumps, with each set comprising 20 repetitions. Isometric knee-extensor strength, counter-movement jump (CMJ) height, delayed-onset muscle soreness (DOMS) and creatine kinase (CK) were measured at baseline, 1, 24, 48 h and 72 h post-exercise. There was a time × group interaction for isometric strength, CMJ and CK (P < 0.05), with differences between the leucine + glutamine and placebo group at 48 h and 72 h for strength (P = 0.013; d = 1.43 and P < 0.001; d = 2.06), CMJ (P = 0.008; d = 0.87 and P = 0.019; d = 1.17) and CK at 24 h (P = 0.012; d = 0.54) and 48 h (P = 0.010; d = 1.37). The leucine group produced higher strength at 72 h compared to placebo (P = 0.007; d = 1.65) and lower CK at 24 h (P = 0.039; d = 0.63) and 48 h (P = 0.022; d = 1.03). Oral leucine or leucine + glutamine increased the rate of recovery compared to placebo after eccentric exercise. These findings highlight potential benefits of co-ingesting these amino acids to ameliorate recovery.
Keywords: Amino acids; Muscle damage; Recovery; Supplementation; Exercise

Cytoplasmic male sterility (CMS) is widely used in plant breeding and represents a perfect model to understand cyto-nuclear interactions and pollen development research. Protein phosphorylation is ubiquitous and is involved in the regulation of diverse cellular processes. To reveal the possible mechanism of CMS and pollen development in kenaf, we performed an iTRAQ-based comparative phosphoproteome analysis in the anthers of a CMS line and wild-type plant (Wt). Whole transcriptome unigenes of kenaf as the reference genome, we identified a total of 3045 phosphorylated sites on 1640 peptides corresponding to 974 unique proteins. 292 of the peptides which corresponding to 247 unique proteins were differentially phosphorylated (fold change ≥ 1.20 with P value< 0.05) between these two materials. 113 and 134 proteins were characterized as up-regulated or down-regulated phosphorylated, respectively. An evaluation of the phosphoproteome and proteomic results indicated that the most significantly phosphorylated proteins were not associated with abundant changes at the protein level. Bioinformatics analysis demonstrated that many of these proteins were involved in various biological processes which may play key roles in pollen development, including carbohydrate metabolism, energy metabolism, transport, gene expression regulation, signal transduction, and cell cycle control. Our results provide insight into the CMS mechanism and pollen development in kenaf from a protein phosphorylation perspective.
Keywords: Kenaf; Pollen; Cytoplasmic male sterility (CMS); Phosphoproteome; iTRAQ

Taurine prevents ethanol-induced apoptosis mediated by mitochondrial or death receptor pathways in liver cells by Gaofeng Wu; Jiancheng Yang; Hao Lv; Wenying Jing; Jiaqi Zhou; Ying Feng; Shumei Lin; Qunhui Yang; Jianmin Hu (863-875).
One pathogenic mechanism of ethanol-induced liver injury is the excessive production of reactive oxygen species (ROS), which may result in alcoholic liver disease (ALD) characterized by cell death due to necrosis and apoptosis. Taurine was proved to protect against liver damage. However, whether taurine attenuates ethanol-induced hepatic apoptosis remains unknown. The present study aims to elucidate this effect and its underlying mechanism. Taurine was administered to ALD rats and an in vitro experiment in which taurine was added to primary rat hepatocytes cultured with ethanol was conducted. Mitochondrial function and anti-oxidative capacity of the liver were tested. TUNEL and AO-EB double staining were conducted to detect apoptosis of liver cells. Expressions of factors and proteins involved in mitochondrial and death receptor pathways were detected by RT-PCR and Western-blot. The results showed that taurine inhibited the decline of cell functions and apoptosis in hepatocytes cultured with ethanol. Furthermore, increased malondialdehyde (MDA) and reduced superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), cytochrome c oxidase (COX) and NADH dehydrogenase (ND) in ALD rats were mediated by taurine. RT-PCR and western-blot results revealed that taurine down-regulated expression of Bax, Fas, Fas ligand (FasL), caspase 3 and caspase 9 while up-regulating the expression of Bcl-2 in ethanol-cultured hepatocytes. In summary, taurine inhibit ethanol-induced hepatic apoptosis by regulating mitochondrial or death receptor pathways.
Keywords: Alcoholic liver disease; Apoptosis; Oxidative damage; Taurine; Rat

Genetic variations in LTA gene and PDCD1 gene and intrauterine infection of hepatitis B virus: a case–control study in China by Tingting Liu; Zhihua Wan; Songxu Peng; Yanni Wang; Hongyan Chen; Xiu Li; Yukai Du (877-883).
Intrauterine infection with hepatitis B virus (HBV) has been suggested to accounting for most cases of chronic HBV infection, which cannot be blocked by combined immunoprophylaxis. The fact that the genetic background might impact the susceptibility to intrauterine infection of HBV has been identified by recent researches. A case-control study included sixty-nine HBsAg-positive mother–newborn pairs with intrauterine infection as cases compared to 138 mother-newborn pairs without intrauterine infection as controls. We studied the correlations between HBV intrauterine transmission and 15 maternal SNPs in eight genes (LTA, LTBR, TNFSF14, PDCD1, APOBEC3B, CD274, CD40 and CD40LG). There was a substantially significantly decreased risk of intrauterine infection of HBV in mothers with the rs2227981 TT genotype in PDCD1 gene compared to those with the rs2227981 GG genotype (OR 0.11, 95% CI 0.01–0.95, P = 0.045). Under recessive model (OR 0.51, 95% CI 0.26-1, P = 0.050) and additive model (OR 0.50, 95% CI 0.28–0.88, P = 0.017), we also found a marginally significantly decreased risk of intrauterine infection of HBV. Furthermore, under additive model, maternal genotype for rs2239704 in LTA gene was marginally significantly related to an increased risk of intrauterine HBV infection (OR 1.62, 95% CI 1–6.66, P = 0.055). However, there were no statistically significant associations among the remaining 13 SNPs and the risk of intrauterine infection of HBV. The examination implied that hereditary variants of PDCD1 and LTA genes were associated with intrauterine infection of HBV.
Keywords: Hepatitis B virus; LTA ; PDCD1 ; Genetic variations; Intrauterine infection

Short-chain consensus alpha-neurotoxin: a synthetic 60-mer peptide with generic traits and enhanced immunogenic properties by Guillermo de la Rosa; Ligia L. Corrales-García; Ximena Rodriguez-Ruiz; Estuardo López-Vera; Gerardo Corzo (885-895).
The three-fingered toxin family and more precisely short-chain α-neurotoxins (also known as Type I α-neurotoxins) are crucial in defining the elapid envenomation process, but paradoxically, they are barely neutralized by current elapid snake antivenoms. This work has been focused on the primary structural identity among Type I neurotoxins in order to create a consensus short-chain α-neurotoxin with conserved characteristics. A multiple sequence alignment considering the twelve most toxic short-chain α-neurotoxins reported from the venoms of the elapid genera Acanthophis, Oxyuranus, Walterinnesia, Naja, Dendroaspis and Micrurus led us to propose a short-chain consensus α-neurotoxin, here named ScNtx. The synthetic ScNtx gene was de novo constructed and cloned into the expression vector pQE30 containing a 6His-Tag and an FXa proteolytic cleavage region. Escherichia coli Origami cells transfected with the pQE30/ScNtx vector expressed the recombinant consensus neurotoxin in a soluble form with a yield of 1.5 mg/L of culture medium. The 60-amino acid residue ScNtx contains canonical structural motifs similar to α-neurotoxins from African elapids and its LD50 of 3.8 µg/mice is similar to the most toxic short-chain α-neurotoxins reported from elapid venoms. Furthermore, ScNtx was also able to antagonize muscular, but not neuronal, nicotinic acetylcholine receptors (nAChR). Rabbits immunized with ScNtx were able to immune-recognize short-chain α-neurotoxins within whole elapid venoms. Type I neurotoxins are difficult to isolate and purify from natural sources; therefore, the heterologous expression of molecules such ScNtx, bearing crucial motifs and key amino acids, is a step forward to create common immunogens for developing cost-effective antivenoms with a wider spectrum of efficacy, quality and strong therapeutic value.
Keywords: Antisera; Elapid; Micrurus ; α-Neurotoxin; Synthetic gene; Recombinant; Three finger toxins

PET imaging of Hsp90 expression in pancreatic cancer using a new 64Cu-labeled dimeric Sansalvamide A decapeptide by Xiaohui Wang; Jun Zhang; Hubing Wu; Yumin Li; Peter S. Conti; Kai Chen (897-907).
Heat shock protein 90 (Hsp90) plays a vital role in the progress of malignant disease and elevated Hsp90 expression has been reported in pancreatic cancer. In this study, we radiolabeled a dimeric Sansalvamide A derivative (Di-San A1) with 64Cu, and evaluated the feasibility of using 64Cu-Di-San A1 for PET imaging of Hsp90 expression in a mouse model of pancreatic cancer. A macrocyclic chelator NOTA (1,4,7-triazacyclononane-1,4,7-trisacetic acid) was conjugated to Di-San A1. 64Cu-Di-San A1 was successfully prepared in a radiochemical yield > 97% with a radiochemical purity > 98%. 64Cu-Di-San A1 is stable in PBS and mouse serum with > 92% of parent probe intact after 4 h incubation. The cell binding and uptake revealed that 64Cu-Di-San A1 binds to Hsp90-positive PL45 pancreatic cancer cells, and the binding can be effectively blocked by an Hsp90 inhibitor (17AAG). For microPET study, 64Cu-Di-San A1 shows good in vivo performance in terms of tumor uptake in nude mice bearing PL45 tumors. The Hsp90-specific tumor activity accumulation of 64Cu-Di-San A1 was further demonstrated by significant reduction of PL45 tumor uptake with a pre-injected blocking dose of 17AAG. The ex vivo PET imaging and biodistribution results were consistent with the quantitative analysis of PET imaging, demonstrating good tumor-to-muscle ratio (5.35 ± 0.46) of 64Cu-Di-San A1 at 4 h post-injection in PL45 tumor mouse xenografts. 64Cu-Di-San A1 allows PET imaging of Hsp90 expression in PL45 tumors, which may provide a non-invasive method to quantitatively characterize Hsp90 expression in pancreatic cancer.
Keywords: PET imaging; Hsp90; Pancreatic cancer; 64Cu labeling; Dimeric Sansalvamide A decapeptide

l-Cysteine is a precursor of glutathione (GSH), a potent physiological antioxidant. Excess glucose-6-phosphate dehydrogenase (G6PD) deficiency in African Americans and low levels of l-cysteine diet in Hispanics can contributes to GSH deficiency and oxidative stress. Oxidative stress and monocyte adhesion was considered to be an initial event in the progression of vascular dysfunction and atherosclerosis. However, no previous study has investigated the contribution of GSH/G6PD deficiency to the expression of monocyte adhesion molecules. Using human U937 monocytes, this study examined the effect of GSH/G6PD deficiency and l-cysteine supplementation on monocyte adhesion molecules. G6PD/GSH deficiency induced by either siRNA or inhibitors (6AN/BSO, respectively) significantly (p < 0.005) increased the levels of cell adhesion molecules (ICAM-1, VCAM-1, SELL, ITGB1 and 2); NADPH oxidase (NOX), reactive oxygen species (ROS) and MCP-1 were upregulated, and decreases in levels of GSH, and nitric oxide were observed. The expression of ICAM-1 and VCAM-1 mRNA levels increased in high glucose, MCP-1 or TNF-α-treated G6PD-deficient compared to G6PD-normal cells. l-Cysteine treatment significantly (p < 0.005) increased G6PD activity and levels of GSH, and decreased NOX, ROS, and adhesion molecules. Thus, GSH/G6PD deficiency increases susceptibility to monocyte adhesion processes, whereas l-cysteine supplementation can restore cellular GSH/G6PD and attenuates NOX activity and expression of cell adhesion molecules.
Keywords: Monocytes; Glucose-6-phosphate dehydrogenase deficiency; Cell adhesion molecules; Oxidative stress; Glutathione; l-Cysteine

Microbial transglutaminase (TGase) has been successfully used to produce site-specific protein conjugates derivatized at the level of glutamine (Gln) or lysine (Lys) residues with diverse applications. Here, we study the drug human interferon β-1a (IFN) as a substrate of TGase. The derivatization reaction was performed using carbobenzoxy-l-glutaminyl-glycine to modify Lys residues and dansylcadaverine for Gln residues. The 166 amino acids polypeptide chain of IFN β-1a contains 11 Lys and 11 Gln residues potential sites of TGase derivatization. By means of mass spectrometry analyses, we demonstrate the highly selective derivatization of this protein by TGase at the level of Lys115 and as secondary site at the level of Lys33, while no reactive Gln residue was detected. Limited proteolysis experiments were performed on IFN to determine flexible regions of the protein under physiological conditions. Interestingly, primary and secondary sites of limited proteolysis and of TGase derivatization occur at the same regions of the polypeptide chain, indicating that the extraordinary selectivity of the TGase-mediated reaction is dictated by the conformational features of the protein substrate. We envisage that the TGase-mediated derivatization of IFN can be used to produce interesting derivatives of this important therapeutic protein.
Keywords: Human interferon β-1a; Protein conjugation; Transglutaminase; Limited proteolysis

This article deals with the synthesis in solid phase and characterization of a nucleoamino amide, based on a phenylalaninamide moiety which was N-conjugated to a thymine nucleobase. In analogy to the natural nucleobase–amino acid conjugates, endowed with a wide range of biological properties, the nucleoamino amide interacts with single-stranded nucleic acids as verified in DNA- and RNA-binding assays conducted by CD and UV spectroscopies. These technologies were used to show also that this conjugate binds serum proteins altering significantly their secondary structure, as evidenced by CD and UV using BSA as a model. The biomolecular recognition seems to rely on the ability of the novel compound to bind aromatic and heteroaromatic moieties in protein and nucleic acids, not hindered by its propensity to self-assemble in aqueous solution, behavior suggested by dynamic light scattering (DLS) and CD spectroscopy in concentration- and temperature-dependent experiments. Finally, the high stability in human serum concurs to define the picture of the nucleoamino amide: this enzymatically stable drug candidate could interfere with protein and single-stranded nucleic acid-driven biological processes, particularly those associated with mRNA poly(A) tail, and its self-assembling nature, in analogy to other l-Phe-based systems, discloses new scenarios in drug delivery technology.
Keywords: Nucleoamino amides; DNA and RNA binding; Spectroscopic properties

Short- and long-term effects of leucine and branched-chain amino acid supplementation of a protein- and energy-reduced diet on muscle protein metabolism in neonatal pigs by Rodrigo Manjarín; Daniel A. Columbus; Jessica Solis; Adriana D. Hernandez-García; Agus Suryawan; Hanh V. Nguyen; Molly M. McGuckin; Rafael T. Jimenez; Marta L. Fiorotto; Teresa A. Davis (943-959).
The objective of this study was to determine if enteral leucine or branched-chain amino acid (BCAA) supplementation increases muscle protein synthesis in neonates who consume less than their protein and energy requirements, and whether this increase is mediated via the upregulation of the mechanistic target of rapamycin complex 1 (mTORC1) pathway or the decrease in muscle protein degradation signaling. Neonatal pigs were fed milk replacement diets containing reduced energy and protein (R), R supplemented with BCAA (RBCAA), R supplemented with leucine (RL), or complete protein and energy (CON) at 4-h intervals for 9 (n = 24) or 21 days (n = 22). On days 9 and 21, post-prandial plasma amino acids and insulin were measured at intervals for 4 h; muscle protein synthesis rate and activation of mTOR-related proteins were determined at 120 min post-feeding in muscle. For all parameters measured, the effects of diet were not different between day 9 or day 21. Compared to CON and R, plasma leucine and BCAA were higher (P ≤ 0.01) in RL- and RBCAA-fed pigs, respectively. Body weight gain, protein synthesis, and activation of S6 kinase (S6K1), 4E-binding protein (4EBP1), and eukaryotic initiation factor 4 complex (eIF4E·eIF4G) were decreased in RBCAA, RL, and R relative to CON (P < 0.01). RBCAA and RL upregulated (P ≤ 0.01) S6K1, 4EBP1, and eIF4E·eIF4G compared to R. In conclusion, when protein and energy are restricted, both leucine and BCAA supplementation increase mTOR activation, but do not enhance skeletal muscle protein synthesis and muscle growth in neonatal pigs.
Keywords: Infant; Growth; Translation initiation; Protein synthesis; Nutrition; mTOR

Skeletal muscle amino acid transporter and BCAT2 expression prior to and following interval running or resistance exercise in mode-specific trained males by Paul A. Roberson; Cody T. Haun; C. Brooks Mobley; Matthew A. Romero; Petey W. Mumford; Jeffrey S. Martin; Michael D. Roberts (961-965).
Endurance (END)- and resistance (RES)-trained males performed interval running or resistance exercise during three consecutive days (bouts 1–3). Muscle biopsies were obtained at baseline, 2 h post-bout 1, and 72 h post-bout 3. Amino acid transporter SNAT2 mRNA was 75% greater in END (group p = 0.008), and increased ~ 70% 2 h post in both groups (time p = 0.023). Amino acid transporter PAT1 mRNA was 2.7-fold greater in RES (group p = 0.002). Baseline protein levels of the mitochondrial aminotransferase BCAT2 were 79% greater in END (p = 0.015).
Keywords: PAT1; SNAT2; BCAT2; Endurance exercise; Resistance exercise

Correction to: Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides by N. Dong; X. R. Li; X. Y. Xu; Y. F. Lv; Z. Y. Li; A. S. Shan; J. L. Wang (967-967).
Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs.