1. By the use of the extended elution system for basic amino acid analysis, 3-methylhistidine has been detected in hydrolysates of actin isolated from mammalian, fish and bird skeletal muscle. 2. Evidence is presented to indicate that 3-methylhistidine forms part of the primary structure and that in rabbit actin this residue is restricted to one peptide fraction obtained from the tryptic digest. 3. Rabbit skeletal-muscle actin has a 3-methylhistidine:histidine ratio 1:7·6, indicating a minimum molecular weight of 47600. 4. Adult rabbit myosin contains approximately 2 3-methylhistidine residues/mol. These residues are localized in the heavy meromyosin part of the molecule, and are restricted to the major component obtained after succinylation.

No abstract

Mutant huntingtin (mHTT) protein carrying the elongated N-terminal polyglutamine (polyQ) tract misfolds and forms protein aggregates characteristic of Huntington’s disease (HD) pathology. A high-affinity ligand specific for mHTT aggregates could serve as a positron emission tomography (PET) imaging biomarker for HD therapeutic development and disease progression. To identify such compounds with binding affinity for polyQ aggregates, we embarked on systematic structural activity studies; lead optimization of aggregate-binding affinity, unbound fractions in brain, permeability, and low efflux culminated in the discovery of compound 1, which exhibited target engagement in autoradiography (ARG) studies in brain slices from HD mouse models and postmortem human HD samples. PET imaging studies with 11C-labeled 1 in both HD mice and WT nonhuman primates (NHPs) demonstrated that the right-hand-side labeled ligand [11C]-1R (CHDI-180R) is a suitable PET tracer for imaging of mHTT aggregates. [11C]-1R is now being advanced to human trials as a first-in-class HD PET radiotracer.

IntroductionSalinity and waterlogging are two major abiotic stresses severely limiting barley production. The lack of a reliable screening method makes it very hard to improve the tolerance through breeding programs.MethodsThis work used 188 DH lines from a cross between a Chinese landrace variety, TX9425 (waterlogging and salinity tolerant), and a Japanese malting barley, Naso Nijo (waterlogging and salinity sensitive), to identify QTLs associated with the tolerance.ResultsFour QTLs were found for waterlogging tolerance. The salinity tolerance was evaluated with both a hydroponic system and in potting mixture. In the trial with potting mixture, only one major QTL was identified to associate with salinity tolerance. This QTL explained nearly 50% of the phenotypic variation, which makes it possible for further fine mapping and cloning of the gene. This QTL was also identified in the hydroponic experiment for different salt-related traits. The position of this QTL was located at a similar position to one of the major QTLs for waterlogging tolerance, indicating the possibility of similar mechanisms controlling both waterlogging and salinity tolerance.ConclusionThe markers associated with the QTL provided a unique opportunity in breeding programs for selection of salinity and waterlogging tolerance.

Aerenchyma formation after 7 days of waterlogging in commercial potting mixture can be a reliable, fast, and widely utilized approach for the selection of waterlogging tolerant barley genotypes. One major QTL for aerenchyma formation after 7 days of waterlogging treatment was identified and the newly developed markers explained 44 % of the phenotypic variance. This QTL can now be effectively used in barley breeding programs. Waterlogging is one of the important limiting conditions for crop yield and productivity. The main feature of waterlogged soils is oxygen deprivation, due to slow gas diffusion in water. Decreased oxygen content in waterlogged soils leads to the oxygen deficiency in plant tissues, resulting in reduced energy availability for plants. Rapidly induced aerenchyma formation is critical to maintaining adequate oxygen supply and overall waterlogging tolerance in barley. In this study, we have proved that quantifying aerenchyma formation after 7 days of waterlogging in commercial potting mixture can be a reliable, fast, and widely utilised approach for the selection of waterlogging tolerant barley genotypes, which is supported by measurements of redox potential (an indicator of anaerobic conditions). This protocol was also used to identify quantitative trait loci (QTL) in a doubled haploid population of barley from the cross between Yerong (tolerant) and Franklin (sensitive) genotypes. The QTL for aerenchyma formation and root porosity were at the same location as the waterlogging tolerance QTL. Seven new markers were developed and added onto this region on chromosome 4H. One major QTL for aerenchyma formation after 7 days waterlogging treatment explained 44.0 % of the phenotypic variance. This successful QTL for aerenchyma formation can be effectively used in the marker assisted selection to improve waterlogging tolerance in barley.

Tissue transglutaminase 2 (TG2) is a multifunctional protein primarily known for its calcium-dependent enzymatic protein cross-linking activity via isopeptide bond formation between glutamine and lysine residues. TG2 overexpression and activity have been found to be associated with Huntington's disease (HD); specifically, TG2 is up-regulated in the brains of HD patients and in animal models of the disease. Interestingly, genetic deletion of TG2 in two different HD mouse models, R6/1 and R6/2, results in improved phenotypes including a reduction in neuronal death and prolonged survival. Starting with phenylacrylamide screening hit 7d, we describe the SAR of this series leading to potent and selective TG2 inhibitors. The suitability of the compounds as in vitro tools to elucidate the biology of TG2 was demonstrated through mode of inhibition studies, characterization of druglike properties, and inhibition profiles in a cell lysate assay.

ABSTRACT:We report a series of irreversible transglutaminase 2 inhibitors starting from a known lysine dipeptide bearing an acrylamide warhead. We established new SARs resulting in compounds demonstrating improved potency and better physical and calculated properties. Transglutaminase selectivity profiling and in vitro ADME properties of selected compounds are also reported.KEYWORDS: plasma stability, polar surface area, acrylamides, celiac disease, in vitro ADME T issue transglutaminase 2 (TG2) is a multifunctional enzyme primarily known for its calcium-dependent protein cross-linking activity. 1 Less well-studied functions include simple amidase, GTPase, ATPase, and protein disulfide isomerase activities. 2−4 TG2 has been characterized in at least three forms, including open, 5 closed, 6 and an open-inactive form. 7 Genetic deletion of TG2 in mice suggests a role for TG2 activity in mitochondrial energy function, 8 and its overactivity has been most closely associated with celiac disease and Huntington's disease (HD). In addition, there is growing support for roles in inflammation and cancer. 9−12 HD is an autosomal dominant, progressive, neurodegenerative disease that is characterized clinically by motor, cognitive, and behavioral deficits. 13 TG2 expression and transglutaminase activity have been shown to be increased in the brains of HD patients, 14 and in vitro and in vivo models have implicated TG2 in HD pathophysiology, 15−18 although more recent contradictory animal data have appeared. 19 The subject of irreversible inhibitors of TG2 has been recently reviewed. 20 Our studies have focused on irreversible inhibitors bearing an acrylamide warhead, 21,22 during which we became interested in dipeptides A and B 23 (Figure 1) as leads due to their attractive potency and specificity for TG2. In a prior report, 21 we established that an excellent correlation exists for several transglutaminase isoforms between the IC 50 values using a 30 min compound incubation and the irreversible inhibition constants, k inact /K i . With this correlation in hand, we relied on the IC 50 values to guide our medicinal chemistry effort. We began by benchmarking dipeptide A, resulting in the selectivity profile illustrated in Figure 1. We also resynthesized and tested several compounds from the Marrano paper, 23 the results of which are found in the Supporting Information. To summarize, the results confirmed that dipeptide A was one of the most potent TG2 inhibitors from this report. As shown in Figure 1, ADME profiling studies on this compound indicated good solubility, low permeability potentially accompanied by efflux, and rapid metabolism in mouse liver microsomes (mLM). Our goal was to identify a tool molecule from this series for in vivo proof of concept studies in HD, where brain is the target organ. Therefore, we focused on increasing potency, improving the absorption profile, and increasing microsomal stability. Lowering the polar surface area (PSA), the number of hydrogen bond donors, and the number of rotatable bon...

ABSTRACTyield, improve some market grade characteristics, and decrease incidence of tomato spotted wilt tospovirus Experiments were conducted from 1999 through 2002 in North(TSWV) (Baldwin and Williams, 2002;Hurt et al., 2003). Interactions of planting pattern and seeding rate with irrigation have been reported for several crops. Irrigation increased corn (Zea mays L.) yield when higher A ltering plant population and row pattern can afplant populations were established compared with lower fect crop yield, quality factors, and pest developplant populations when row pattern was held constant ment in peanut. Pod yield of bunch-type peanut was (Liang et al., 1992). In contrast, corn yield did not in-16% higher when peanut was seeded in rows spaced crease when plant population was increased in absence 46 cm apart compared with 91 cm (Norden and Lipsof irrigation (Liang et al., 1992). In soybean [Glycine comb, 1974). Duke and Alexander (1964) reported pod max (L.) Merr.], increasing plant populations and deyield that was 14% higher in narrow row plantings comcreasing row width increased yield (Lehman and Lampared with traditional wider row patterns using largebert, 1960). In cotton (Gossypium hirsutum L.), yield seeded Virginia bunch-type peanut. Spanish market increases were noted when seeding rate was increased type peanut planted in 46-cm rows yielded higher than and row spacing was decreased (Briggs et al., 1967; Heitpeanut planted in rows spaced 61, 76, 91, or 107 cm apart holt et al., 1992;Hoskinson et al., 1974). at similar in-row plant populations (Parham, 1942). Cox Determining interactions of seeding rate and planting and Reid (1965) reported that increasing plant populapattern with variables such as cultivar selection and tions by increasing in-row seeding rate or by decreasing irrigation will assist growers and their advisors in develrow width increased pod yield.oping efficient production and pest management sysAlthough the majority of peanut in the USA is seeded tems for peanut. Therefore, research was conducted to in single rows spaced 91 to 102 cm apart, research sugcompare peanut pod yield, market grade characteristics, gests that seeding peanut in standard twin row patterns and TSWV severity when peanut was seeded in various (rows spaced approximately 18 cm apart with centers planting patterns, seeding rates, and cultural practices. of these rows spaced 91 to 102 cm apart) can increase MATERIALS AND METHODS