Bimolecular triplex formation between 5'-d-(AG)nT4(CT)n and 5'-d-(TC)n as functions of helix length and buffer

It was observed that a group of unusually stable DNA hairpins (Hn: 5'-d-(AG)nT4(CT)n, n = 2-4) were directed to homopyrimidine sequences (Pn: 5'-d-(TC)n) by py x pu x py-type triplex formation, resulting in high binding affinity and specificity. The spectroscopic results (UV and CD) showed that the short bimolecular triplex Hn:Pn could be formed in acidic conditions (pH 4.5-6.0) as helix length n > 2, and further extending to neutral pH as n = 4. This hairpin strategy for recognition of a pyrimidine strand has a substantial binding advantage over either the conventional linear analog or simple Watson-Crick complement. Triplex stability of Hn with Pn is not only pH-dependent, as expected for triplexes involving C+. GC triads, but also sensitive to the buffer. The triplex H4:P4 was formed in the phosphate buffers of pH 6.0-7.0 but already dissociated above pH 6.5 in the buffer of cacodylate, MOPSO or PIPES. By contrast, the nature of a buffer had no major influence on stability of a hairpin duplex. Here we provide a simple triplex system, and the data presented here may be useful in defining the experimental conditions necessary to stabilize triplex DNA.     

Effect of G-tract length on the topology and stability of intramolecular DNA quadruplexes

G-Rich sequences are known to form four-stranded structures that are based on stacks of G-quartets, and sequences with the potential to adopt these structures are common in eukaryotic genomes. However, there are few rules for predicting the relative stability of folded complexes that are adopted by sequences with different-length G-tracts or variable-length linkers between them. We have used thermal melting, circular dichroism, and gel electrophoresis to examine the topology and stability of intramolecular G-quadruplexes that are formed by sequences of the type d(GnT)4 and d(GnT2)4 (n = 3-7) in the presence of varying concentrations of sodium and potassium. In the presence of potassium or sodium, d(GnT)4 sequences form intramolecular parallel complexes with the following order of stability: n = 3 > n = 7 > n = 6 > n = 5 > n = 4. d(G3T)4 is anomalously stable. In contrast, the stability of d(GnT2)4 increases with the length of the G-tract (n = 7 > n = 6 > n = 5 > n = 4 > n = 3). The CD spectra for d(GnT)4 in the presence of potassium exhibit positive peaks around 260 nm, consistent with the formation of parallel topologies. These peaks are retained in sodium-containing buffers, but when n = 4, 5, or 6, CD maxima are observed around 290 nm, suggesting that these sequences [especially d(G5T)4] have some antiparallel characteristics. d(G3T2)4 adopts a parallel conformation in the presence of both sodium and potassium, while all the other d(GnT2)4 complexes exhibit predominantly antiparallel features. The properties of these complexes are also affected by the rate of annealing, and faster rates favor parallel complexes.     

Length-dependent formation of parallel-stranded DNA in alternating AT segments

Parallel-stranded DNA can be formed from alternating AT segments and is not restricted exclusively to homooligomeric AT sequences. DNA oligonucleotides 3'-d(AT)nxC4(AT)n-3' (where x indicates the location of the 5'-5' phosphodiester linkage) form parallel-stranded hairpin structures at micromolar strand concentration for n = 4 or 5 but not for n = 6, 7. The spectral properties of the parallel-stranded structures are similar to those of the hairpin structures containing homooligomeric AT stems. However, parallel-stranded structures formed in alternating AT segments are significantly less stable than either their corresponding antiparallel control or the homooligomeric parallel AT hairpins as evidenced by their lower helix-coil transition enthalpy, melting temperature, and stability constant. This results in a remarkable polymorphism which is most pronounced for 3'-d(AT)5xC4(AT)5-3'. This oligonucleotide can exist as a parallel-stranded hairpin, coil, or concatameric antiparallel structure(s), depending on temperature and strand concentration. These results suggest simple guidelines for the design of parallel-stranded DNA. In addition, we present a model for the assessment of the stability of parallel-stranded duplex structures formed from AT base pairs based on their sequence.     

Interaction of Polymer Aggregates Based on Stearoyl-poly-N-vinylpyrrolidone with Blood Components

Stearoyl-poly-N-vinylpyrrolidone (PVP-stear) of various molecular weights (M(n) = 1500-5500) self-assemble in aqueous medium. Particles prepared from PVP-stear were characterized in terms of shape and size distribution, and the mechanical stability of the particles was studied. The interaction of PVP-stear and its aggregates with blood components was investigated. Aggregates formed by the polymers with M(n) = 1500-3500 in the presence of human serum are stable. The direct lytic action of PVP-stear preparations was studied using sheep and human erythrocytes. The influence of PVP-stear aggregates on the activation of complement system both on classical and alternative pathways was examined. The aggregates prepared from PVP-stear of various molecular weights had no effect on the activation of the complement system.     

Theta and alpha-band EEG spatial synchronization under the conditions of visual set, formed to an angry face expression. A study of 5-11-year-old children

EEG coherence in theta and alpha bands during set-forming and set-shifting was studied in 5-6-year-old (n=18) and 10-11-year-old (n=25) children. Set was formed to visual stimuli (facial photos with emotionally negative expression). Younger children displayed smaller coherence values, especially in the right hemisphere, than older ones. We also revealed differences in theta and alpha band coherence in cases of a rigid and a plastic set. For example, EEG-coherence values were smaller when cognitive processes were relatively rigid (i.e., in a case of a slower set-shifting). A strong correlation between electrophysiological and behavioral data supports the hypothesis that cortico-hippocampal and fronto-thalamic brain integration systems participate in facial expression recognition and provide cognition flexibility.     

Interaction of basic oligo-L-amino acids with deoxyribonucleic acids. Oligo-L-arginines of various chain lengths and herring sperm DNA

The interaction of DNA and oligo-L-arginines having definite chain lengths of 1-17 residues was studied by precipitate formation and thermal denaturation of the complexes in order to obtain a better understanding of the roles of nuclear basic proteins. The results can be summarized as follows. 1. Those oligo-L-arginines, (Arg)n, in which n greater than or larger than 4 can bind with DNA irreversibly to form precipitates of the complexes. Among them, oligomers larger than (Arg)5 precipitate DNA completely in Arg/P input ratios below 1. The Arg/P ratios in the precipitates are between 0.6-0.8. 2. The thermal stability of the complexes depends on the method of complex formation, and complexes formed by the dialysis method are more stable than those formed by the mixing method. 3. The binding of (Arg)n to DNA was found to be reversible and in a equilibrium for n less than or equal to 6. In general, the longer the oligomer, the higher the stability of the complex at a definite Arg/P ratio. 4. For (Arg)7-10, three kinds of complexes with different stabilities are formed between DNA and oligopeptides. 5. For (Arg)14-17, only a restricted type of complexes can be formed between DNA and oligomers, as in the case with poly-L-arginine or protamines. 6. The interaction between basic nuclear proteins and DNA is discussed in the light of the basic region in protamine and histone molecules.     

Oral gene delivery: design of polymeric carrier systems shielding toward intestinal enzymatic attack

The gastrointestinal tract poses a variety of morphological and physiological barriers to the expression of target genes. The aim of this study was to evaluate the stability of cationic polymer/pDNA nanoparticles toward salts and enzymes of the intestinal fluid. Within this study, a chitosan-enzyme inhibitor conjugate has been generated and characterized. Based on this conjugate, nanoparticles with pDNA were generated to enhance transfection rate in oral gene delivery. The enzyme inhibitor aurintricarboxylic acid (ATA) was covalently bound to chitosan to improve the enzymatic stability of nanoparticles formed with this polymer and pDNA. Chitosan-ATA/pDNA nanoparticles showed a size of 98.5 +/- 26 nm and a zeta potential of -13.26 +/- 0.24 mV (n = 3-4). Stability studies with salt solution, lysozyme, DNase, and freshly collected porcine intestinal fluid showed that chitosan-ATA/pDNA nanoparticles are significantly (p < 0.05) more stable than unmodified chitosan/pDNA nanoparticles. Apart from improved stability, chitosan-ATA/pDNA nanoparticles showed a 2.6-fold higher transfection rate than chitosan/pDNA nanoparticles in the Caco-2 cell line, thus creating a promising carrier for orally administered therapeutic genes.     

Dependence of the verbal set on the cognitive activity context

It was shown in adult healthy subjects (n = 60) that the set depends on the context of cognitive activity. Under conditions of its complication, when a subject had to solve successively several tasks, the stability of the verbal set markedly increased. This was expressed in a longer effect of "blindness" characteristic for the set to pseudo-word reading and increase in the time of reaction to a probe stimulus.     

Quantitative analysis of human enteric adenoviruses in aquatic environments

AIMS: The aim of this study was to determine human adenoviruses (HuAdVs) in aquatic environments by real-time polymerase chain reaction (PCR). METHODS AND RESULTS: In order to describe the ratio of enteric serotypes to the total HuAdVs, the primer set specific for the enteric serotypes 40 and 41 was used in parallel with the universal primer set for all 51 serotypes of HuAdVs. The enteric serotypes of HuAdVs were detected at the concentration of 7.3-1500 PCR-detection units (PDU) per ml in raw sewage (n = 17), 0.00060-4.1 PDU ml(-1) in secondary-treated sewage before chlorination (n = 17), 0.0018-7.0 PDU ml(-1) in river water (n = 36), and 0.032-6.1 PDU ml(-1) in seawater (n = 18). The concentration of HuAdVs, determined by the universal primer set, was equivalent to that of enteric serotypes in almost all the samples tested. CONCLUSIONS: Enteric serotypes were predominant among all serotypes of HuAdVs in the aquatic environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The abundance of enteric serotypes of HuAdVs should be more emphasized than other serotypes in order to assess the risk of their infection via water.     

The effect of single versus multiple sets on strength

Research has previously been divided on whether performing resistance training with a single set per training session is as effective for increasing strength as training with multiple sets. The purpose of this study was to determine the effect of single sets versus multiple sets on strength. Forty subjects were randomly assigned into 1 of 3 groups: control (C; n = 8), single set (SS; n = 14), or multiple sets (MS; n = 18) to perform 8 maximal knee extensions at 60 degrees .s(-1) on a Biodex System 3 isokinetic dynamometer twice a week for 8 weeks. The SS group performed 1 set while the MS group performed 3 sets. All groups were pre-, mid- (4 weeks), and posttested at 60 degrees x s(-1). Strength was expressed as peak torque (PT). A 3 x 3 x 2 (time x group x sex) mixed factor repeated measures analysis of variance (ANOVA) revealed no interaction involving sex, but there was an interaction of group by time. The MS group exhibited a significant (p < 0.05) increase in PT (pre = 171.39 +/- 61.98 Nm; mid = 193.08 +/- 66.23 Nm) between the pretest and the midtest while the SS (pre = 163.45 +/- 56.37 Nm; mid = 172.60 +/- 61.78 Nm) and C groups (pre = 135.997 +/- 54.31 Nm; mid = 127.66 +/- 53.12 Nm) did not change. Strength did not change between the midtest and the posttest for any group. It was concluded that performing 3 sets of isokinetic knee extensions was more effective than performing a single set for increasing peak torque. These results seem to indicate that for increasing strength of the quadriceps, performing multiple sets is superior to performing a single set of resistance exercise.     

Sequence dependence of the stability of RNA hairpin molecules with six nucleotide loops

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequence of the types GCGXUAAUYCGC and GGUXUAAUYACC with Watson-Crick loop closure, where XY is the set of 10 possible mismatch base pairs. A nearest-neighbor analysis of the data indicates the free energy of loop formation at 37 degrees C varies from 3.1 to 5.1 kcal/mol. These results agree with the model previously developed [Vecenie, C. J., and Serra, M. J. (2004) Biochemistry 43, 11813] to predict the stability of RNA hairpin loops: DeltaG degrees (37L(n) = DeltaG degrees (37i(n) + DeltaG degrees (37MM) - 0.8 (if first mismatch is GA or UU) - 0.8 (if first mismatch is GG and loop is closed on the 5' side by a purine). Here, DeltaG degrees (37i(n) is the free energy for initiating a loop of n nucleotides, and DeltaG degrees (37MM) is the free energy for the interaction of the first mismatch with the closing base pair. Thermodynamic parameters are also reported for hairpin formation in 1 M NaCl by RNA sequence of the types GACGXUAAUYUGUC and GGUXUAAUYGCC with GU base pair closure, where XY is the set of 10 possible mismatch base pairs. A nearest-neighbor analysis of the data indicates the free energy of loop formation at 37 degrees C varies from 3.6 to 5.3 kcal/mol. These results allow the development of a model for predicting the stability of hairpin loops closed by GU base pairs. DeltaG degrees (37L(n) (kcal/mol) = DeltaG degrees (37i(n) - 0.8 (if the first mismatch is GA) - 0.8 (if the first mismatch is GG and the loop is closed on the 5' side by a purine). Note that for these hairpins, the stability of the loops does not depend on DeltaG degrees (37MM). For hairpin loops closed by GU base pairs, the DeltaG degrees (37i(n) values, when n = 4, 5, 6, 7, and 8, are 4.9, 5.0, 4.6, 5.0, and 4.8 kcal/mol, respectively. The model gives good agreement when tested against six naturally occurring hairpin sequences. Thermodynamic values for terminal mismatches adjacent to GC, GU, and UG base pairs are also reported.     

Solid-phase synthesis of europium-labeled human INSL3 as a novel probe for the study of ligand-receptor interactions

An efficient solid-phase synthesis protocol has been developed which, together with regioselective sequential formation of the three disulfide bonds, enabled the preparation of specifically monolanthanide (europium)-labeled human insulin-like peptide 3 (INSL3) for the study of its interaction with its G-protein-coupled receptor, RXFP2, via time-resolved fluorometry. A commercially available chelator, diethylene triamine pentaacetic acid (DTPA), was coupled to the N-terminus of the INSL3 A-chain on the solid phase, and then a coordination complex between europium ion and DTPA was formed using EuCl 3 to protect the chelator from production of an unidentified adduct during subsequent combination of the A- and B-chains. The labeled peptide was purified in high yield using high-performance liquid chromatography with nearly neutral pH buffers to prevent the liberation of Eu (3+) from the chelator. Using time-resolved fluorometry, saturation binding assays were undertaken to determine the binding affinity (p K d) of labeled INSL3 for RXFP2 in HEK-293T cells stably expressing RXFP2. The dissociation constant of DTPA-labeled INSL3 (9.05 +/- 0.03, n = 3) that was obtained from saturation binding experiments was comparable to that of (125)I-labeled INSL3 (9.59 +/- 0.09, n = 3). The receptor binding affinity (p K i) of human INSL3 was determined to be 9.27 +/- 0.06, n = 3, using Eu-DTPA-INSL3 as a labeled ligand, which again is similar to that obtained when (125)I-INSL3 was used as labeled ligand (9.34 +/- 0.02, n = 4). This novel lanthanide-coordinated, DTPA-labeled INSL3 has excellent sensitivity, stability, and high specific activity, properties that will be particularly beneficial in high-throughput screening of INSL3 analogues in structure-activity studies.     

Sequestration of biogenic amines by alginic and fulvic acids

The interaction of natural (alginic and fulvic acids) and synthetic (polyacrylic acid 2.0 kDa) polyelectrolytes with some protonated polyamines [diamines: ethylendiamine, 1,4-diaminobutane (or putrescine), 1,5-diaminopentane (or cadaverine); triamines: N-(3-aminopropyl)-1,4-diaminobutane (or spermidine), diethylenetriamine; tetramine: N,N'-bis(3-aminopropyl)-1,4-diaminobutane (or spermine); pentamine: tetraethylene-pentamine; hexamine: pentaethylenehexamine] was studied at T=25 degrees C by potentiometry and calorimetry. Measurements were performed without supporting electrolyte, in order to avoid interference, and results were reported at I=0 mol L(-)(1). For all the systems, the formation of (am)L(2)H(i) species was found (am=amine; L=polyelectrolyte; i=1...4, depending on the amine considered). The stability of polyanion-polyammonium cation complexes is always significant, and for high-charged polycations, we observe a stability comparable to that of strong metal complexes. For example, by considering the formation reaction (am)H(i)+2L=(am)L(2)H(i) we found log K(i)=6.0, 6.5 and 10.8 for i=1, 2 and 3, respectively, in the system alginate-spermidine. Low and positive formation DeltaH(degrees) values indicate that the main contribution to the stability is entropic in nature. The sequestering ability of polyelectrolytes toward amines was modelled by a sigmoid Boltzman type equation. Some empirical relationships between stability, charges and DeltaG(degrees) and TDeltaS(degrees) are reported. Mean values per salt bridge of formation thermodynamic parameters (DeltaX(degrees) (n)) are DeltaG(degrees) (n)=-5.8+/-0.4, DeltaH degrees (n)=0.7+/-0.5 and TDeltaS(degrees) (n)=6.5+/-0.5 kJmol(-)(1) for all the systems studied in this work.     

Formation and structural determinants of multi-stranded guanine-rich DNA complexes

We have investigated the complexes formed by oligonucleotides with the general sequence d(T15,Gn), where n = 4-15. Two distinct classes of structures are formed, namely, the four-stranded tetraplex and frayed wires. Frayed wires differ from four-stranded tetraplexes in both strand association stoichiometry and the ability of dimethyl sulfate to methylate the N7 position of guanine. Thus, it appears that these two guanine-rich multistranded assemblies are stabilised by different guanine-guanine interactions. The number of contiguous guanine residues determines which of the complexes is favoured. Based on the stoichiometry of the associated species and the accessibility of the N7 position of guanine to methylation we have found that oligonucleotides with smaller number of contiguous guanines; n = 5-8, form primarily four-stranded tetraplex. Oligonucleotides with larger numbers of contiguous guanines adapt primarily the frayed wire structure. The stability of the complexes formed by this series of oligonucleotides is determined by the number and arrangement of the guanines within the sequences. We propose that the formation of the two types of complex proceed by a parallel reaction pathways that may share common intermediates.     

Stable transformation of barley callus using biolistic® particle bombardment and the phosphinothricin acetyltransferase (bar) gene

We have previously studied chromosomal and morphological variation in protoplast cultures of diploid petunia (Petunia hybrida) plants. We found that 85% of the regenerants were tetraploid (2n=4x=28). These plants flowered and set seeds.In the present study, the cytological stability of plants regenerated from leaf mesophyll protoplast cultures derived from the progeny of the self-fertile tetraploid plants was assessed on the basis of mitotic analysis, morphological characters, and protein patterns. When we analyzed the root tip chromosomes of 117 regenerants derived from 39 protoclone calluses, all of the regenerants tested retained the parental chromosome number of 2n=4x=28. One hundred regenerants were further analyzed and displayed normal vegetative morphology and retained the floral characteristics of the seed-derived plants from which they were derived. No significant variations in any character were observed among regenerants. When leaf protein patterns from four regenerated tetraploid protoclones were analyzed by two-dimensional polyacrylamide gel electrophoresis and compared with those of seed-derived plants, the protein patterns exhibited great similarity.The data suggest that tetraploidization of petunia plant increases cytological stability during further in vitro cultures and may play an important role in the genetic stability of regenerant populations.Abbreviations BA benzylaminopurine - IAA indole-3-acetic acid - IEF isoelectric-focusing - PVP polyvinylpyrrolidone - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

FTIR and UV spectroscopy studies of triplex formation between pyrimidine methoxyethylphosphoramidates alpha-oligodeoxynucleotides and ds DNA targets

The ability of non-ionic methoxyethylphosphoramidate (PNHME) alpha-oligodeoxynucleotides (ODNs), alpha dT(15) and alpha dCT dodecamer, to form triplexes with their double-stranded DNA targets was evaluated. Thermal stability of the formed complexes was studied by UV thermal denaturation and the data showed that these PNHME alpha-ODNs formed much more stable triplexes than phosphodiester (PO) beta-ODNs did (Delta Tm = + 20 degrees C for alpha dCT PNHME). In addition, FTIR spectroscopy was used to determine the base pairing and the strand orientations of the triplexes formed by alpha dT(15) PNHME compared to phosphodiester ODNs with beta or alpha anomeric configuration. While beta dT(15) PO failed to form a triplex with a long beta dA(n) x beta dT(n) duplex, the Tm of the Hoogsteen part of the triplex formed by alpha dT(15) PNHME reached 40 degrees C. Moreover alpha dT(15) PNHME displaced the beta dT(15) strand of a shorter beta dA(15) x beta dT(15) duplex. The alpha dCT PNHME and alpha dT(15) PNHME third strands were found antiparallel in contrast to alpha dT(15) PO which is parallel to the purine strand of their duplex target. The uniform preferential Hoogsteen pairing of the nucleotides alpha dT and alpha dC combining both replacements might contribute to the improve stability of the triplexes.     

Stability of RNA hairpin loops closed by AU base pairs

Thermodynamic parameters are reported for hairpin formation in 1 M NaCl by RNA sequence of the type GCAXUAAUYUGC, where XY is the set of 10 possible mismatch base pairs. A nearest-neighbor analysis of the data indicates that the free energy of loop formation at 37 degrees C varies from 3.2 to 5.0 kcal/mol. These results combined with the model previously developed [Dale et al. (2000) RNA 6, 608] allow improvements in the model to predict the stability of RNA hairpin loops: DeltaG degrees (37L(n) = DeltaG degrees (37i(n)) + DeltaG degrees (37MM) - 0.8 (if first mismatch is GA or UU) - 0.8 (if first mismatch is GG and loop is closed on 5' side by a purine). Here, DeltaG degrees (37i(n) is the free energy for initiating a loop of n nucleotides, and DeltaG degrees (37MM) is the free energy for the interaction of the first mismatch with the closing base pair. Hairpins with GG first mismatches were found to vary in stability depending upon the orientation of the closing base pair (5' or 3' purine relative to the loop). The model gives good agreement when tested against four naturally occurring hairpin sequences.     

The stoichiometry and stability of the NADP complexes with manganese(II) ions as studied by electron paramagnetic resonance.

Magnetic resonance techniques have been applied to study the stability of the complexes formed between Mn(II) ions and NADP in aqueous solutions at a pH of 7.5 and 20 degrees C. The electron paramagnetic resonance (epr) data indicate that at low Mn(II) ion concentrations ([Mn(II)] less than 1 mM; [NADP] approximately 5 mM), a 1:1 complex is formed with an apparent stability constant K1 = 370 +/- 50 M-1 at an ionic strength of 0.22 in the presence of 0.20 M Cl-. At high Mn(II) ion concentrations, a Mn(II)2-NADP species, with an apparent stability constant K2 = 54 +/- 17 M-1, is present in significant amounts. When the epr data are corrected for the presence of the MnCl+ ion, the analysis of the new Scatchard plot yields stability constants for the two sites of K1 = 640 +/- 90 M-1 and K2 = 88 +/- 13 M-1, respectively. The presence of two metal ion binding sites on the NADP molecule has not been observed previously, and previous workers have always analyzed their data in terms of the 1:1 Mn(II)-NADP complex. An epr temperature study of K1 yields a value of delta H equal to 1.3 +/- 0.2 kcal/mol (1 cal = 4.187 J).     

K+ and Na+-induced self-assembly of telomeric oligonucleotide d(TTAGGG)n

The telomeric DNA oligomers, d(TTAGGG)(n), where n=1, 2, 4, could self-associate into the multi-stranded structures in appropriate condition, exhibited different CD spectra. The presense of Na(+) was more advantage to facilitate the formation of anti-parallel conformation, but the presense of K(+) enhanced their thermal stability. Spectroscopic analysis of 3, 3'-diethyloxadicarbocyanine (DODC) showed the formation of hairpin quadruplex structures for d(TTAGGG)(2) and d(TTAGGG)(4), but d(TTAGGG) could not. The four-stranded tetraplexes and branched nanowire formed in the presense of K(+) or Na(+) alone were observed by atomic force microscopy (AFM). The ability of d(TTAGGG)(n) to self-assemble into four-stranded tetraplexes and nanowires depends strongly on the number of repeating units and ionic environment. A model to explain how these structures formed is proposed.     

Neuromuscular training improves knee kinematics, in particular in valgus aligned adolescent team handball players of both sexes

The purpose of this study was to investigate the effects of added neuromuscular training (NMT), as compared to just regular training (RT), on lower extremity kinematics and single leg stability in adolescent team handball players of both sexes and to investigate whether these effects are more evident in valgus aligned athletes. Eighty adolescent team handball players (NMT: n = 49, RT: n = 31) were tested on knee kinematics in a drop jump and single leg stability in a 1-leg hop test. Based on the initial results in the drop jump test, both groups were subdivided into an above-average valgus aligned (AAVA; NMT: n = 27, RT: n = 22) and a below average valgus aligned (NMT: n = 22, RT: n = 9) group. All groups received 10 weeks of handball training either without (RT) or with in-season NMT. A significant interaction of training and valgus group was found for all absolute and for 2 out of 4 normalized knee distances in the drop jump test (p < 0.024) and for contact time after the first landing (p = 0.029). The AAVA-NMT group showed the largest relative progression (18-37%) for all these parameters. In the 1-leg hop test, a significant effect of NMT compared to RT was found for both legs (p < 0.042). Compared to RT alone, added in-season NMT has the greatest benefits on knee kinematics and single leg stability, in particular in AAVA adolescent team handball players of both sexes. The results of this study suggest that adolescent team handball players of both sexes should be given NMT, 20 minutes twice a week for 10 weeks to improve landing kinematics and single leg stability. "At risk" players with higher initial valgus angles will benefit most from this NMT.