Bernstein collocation technique for a class of Sturm-Liouville problems.

Sturm-Liouville problems have yielded the biggest achievement in the spectral theory of ordinary differential operators. Sturm-Liouville boundary value issues appear in many key applications in natural sciences. All the eigenvalues for the standard Sturm-Liouville problem are guaranteed to be real and simple, and the related eigenfunctions form a basis in a suitable Hilbert space. This article uses the weighted residual collocation technique to numerically compute the eigenpairs of both regular and singular Strum Liouville problems. Bernstein polynomials over [0,1] has been used to develop a weighted residual collocation approach to achieve an improved accuracy. The properties of Bernstein polynomials and the differentiation formula based on the Bernstein operational matrix are used to simplify the given singular boundary value problems into a matrix-based linear algebraic system. Keeping this fact in mind such a polynomial with space defined collocation scheme has been studied for Strum Liouville problems. The main reasons to use the collocation technique are its affordability, ease of use, well-conditioned matrices, and flexibility. The weighted residual collocation method is found to be more appealing because Bernstein polynomials vanish at the two interval ends, providing better versatility. A multitude of test problems are offered along with computation errors to demonstrate how the suggested method behaves. The numerical algorithm and its applicability to particular situations are described in detail, along with the convergence behavior and precision of the current technique.

Axisymmetric boundary layer slip flow with heat transfer over an exponentially stretching bullet-shaped object: A numerical assessment.

The slip flow and thermal transfer inside the boundary layer are extremely significant for various problems in aerodynamics, wing stall, skin friction drag on an entity, high-level velocity aircraft, etc. The current research investigated the effect of the slip factor and shape factor on the axisymmetric bullet-shaped object by taking the viscous dissipation parameter and location parameter. The analysis is conducted for both fixed and moving bullet-shaped objects due to thinner and thicker surfaces. The governing equations are transformed into a system of ordinary differential equations using suitable local axisymmetric similarity transformations and solved by applying the spectral quasi-linearization method. A new correlation analysis is made for velocity and temperature gradients. It is observed that the boundary layer structure has no defined shape due to a thicker bullet-shaped object instead it forms a steep angle with the axis which is contradictory to the formation of the boundary layer. A negative correlation is observed for the parameters M, Ec, Q*, and s but a positive correlation is observed for the parameters such as Pr, P, λ, and ε. The surface thickness and stretching ratio significantly affect the fluid flow and heat transfer processes. It is also noticed that the thinner bullet-shaped object performs as a better cooling conductor compared to a thicker one. The skin friction is reduced in the case of a thinner bullet-shaped object compared to a thicker one. The present analysis reveals that the heat transfer rate and the friction factor may be helpful in industrial sectors for controlling the cooling rate and quality of the final product. This research brings forward to increase in the rate of heat transfer inside the boundary layer region. The result may help to design the various types of moving objects in the automobile engineering sector when the objects pass through the fluid.

The Influence of Carrying Anterior Load on the Sagittal and Frontal Plane Kinematics of Lower Extremities during Stair Ascending.

BACKGROUND: Anterior load carriage is a one of the commonly performed activities in some industries. Stair climbing while carrying anterior load significantly alters different biomechanical mechanisms that can potentially affect the musculoskeletal function of the lower extremities. OBJECTIVE: The study aims to assess the effect of carrying an anterior load (20% of body weight) on lower extremity kinematics during the kinematical phases of stairs ascent (weight acceptance, pull up, forward continuance, and swing phase). MATERIAL AND METHODS: In this experimental study, data were collected through the use of a custom made wooden staircase and OPtiTrack motion capture system was composed of 12 infrared cameras and a per modeled reflective marker set. Sixteen female college students volunteered to conduct two tasks of ascending stairs with and without an anterior load of approximately 20% of their body weight. The collected frontal and sagittal plane lower extremity joint angles were calculated using MATLAB software (version R2015a). Statistical comparison between the two study tasks was made using IBM SPSS Statistics software (version 25.0; SPSS Inc., Chicago, IL, USA). RESULTS: Based on the results, there is significant difference (p-value < 0.05) between the two study tasks during ascending stair phases in all three sagittal plan lower extremity joint angles. CONCLUSION: Anterior load carried during stair ascent causes participants to depend more on the hip joint (higher flexion angles) compared to stair ascent without loads, which may increase the risk of falls and injuries, and the importance of muscle-strengthening activities and highlight the use of appropriate technique during load carriage.

Response of plantain (Plantago lanceolata L.) supplementation on nutritional, endo-parasitic, and endocrine status in lambs.

The aim of the present study was to assess the effects of plantain herb (Plantago lanceolata L.) supplementation on growth, plasma metabolites, liver enzymatic activity, hormonal status, gastrointestinal parasites, and carcass characteristics of lambs. A total of 24 lambs, aged 6 months weighing 8.0 ± 0.5 kg were randomly allocated to one of two dietary treatments: (1) CL diet-roadside grass and concentrate mixture; (2) PL diet-CL diet + 5% fresh plantain supplementation on a DM basis. The PL diet group exhibited 23% higher (P = 0.01) average daily gain and 15% improved (P = 0.03) feed conversion efficiency. Circulating cholesterol concentrations were suppressed by 9% (P = 0.03), and liver enzyme activity was improved by 5-25% (P < 0.05) in the lamb fed PL diet, compared with CL diet only. The inclusion of plantain in the diet was highly effective at suppressing the parasites, Paramphistomum spp. (P = 0.003) and coccidial parasites (P = 0.04), but not stomach worms. Moreover, plantain supplementation increased growth hormone and insulin concentrations in plasma level, whereas decreased carcass fat by 32.7%. Therefore, supplementation of the lambs' diet with plantain showed some beneficial effects on productivity and parasitic infection, while it led to a leaner carcass.

Genetic effects of FASN, PPARGC1A, ABCG2 and IGF1 revealing the association with milk fatty acids in a Chinese Holstein cattle population based on a post genome-wide association study.

BACKGROUND: A previous genome-wide association study deduced that one (ARS-BFGL-NGS-39328), two (Hapmap26001-BTC-038813 and Hapmap31284-BTC-039204), two (Hapmap26001-BTC-038813 and BTB-00246150), and one (Hapmap50366-BTA-46960) genome-wide significant single nucleotide polymorphisms (SNPs) associated with milk fatty acids were close to or within the fatty acid synthase (FASN), peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PPARGC1A), ATP-binding cassette, sub-family G, member 2 (ABCG2) and insulin-like growth factor 1 (IGF1) genes. To further confirm the linkage and reveal the genetic effects of these four candidate genes on milk fatty acid composition, genetic polymorphisms were identified and genotype-phenotype associations were performed in a Chinese Holstein cattle population. RESULTS: Nine SNPs were identified in FASN, among which SNP rs41919985 was predicted to result in an amino acid substitution from threonine (ACC) to alanine (GCC), five SNPs (rs136947640, rs134340637, rs41919992, rs41919984 and rs41919986) were synonymous mutations, and the remaining three (rs41919999, rs132865003 and rs133498277) were found in FASN introns. Only one SNP each was identified for PPARGC1A, ABCG2 and IGF1. Association studies revealed that FASN, PPARGC1A, ABCG2 and IGF1 were mainly associated with medium-chain saturated fatty acids and long-chain unsaturated fatty acids, especially FASN for C10:0, C12:0 and C14:0. Strong linkage disequilibrium was observed among ARS-BFGL-NGS-39328 and rs132865003 and rs134340637 in FASN (D´ > 0.9), and among Hapmap26001-BTC-038813 and Hapmap31284-BTC-039204 and rs109579682 in PPARGC1A (D´ > 0.9). Subsequently, haplotype-based analysis revealed significant associations of the haplotypes encompassing eight FASN SNPs (rs41919999, rs132865003, rs134340637, rs41919992, rs133498277, rs41919984, rs41919985 and rs41919986) with C10:0, C12:0, C14:0, C18:1n9c, saturated fatty acids (SFA) and unsaturated fatty acids (UFA) (P = 0.0204 to P < 0.0001). CONCLUSION: Our study confirmed the linkage between the significant SNPs in our previous genome-wide association study and variants in FASN and PPARGC1A. SNPs within FASN, PPARGC1A, ABCG2 and IGF1 showed significant genetic effects on milk fatty acid composition in dairy cattle, indicating their potential functions in milk fatty acids synthesis and metabolism. The findings presented here provide evidence for the selection of dairy cows with healthier milk fatty acid composition by marker-assisted breeding or genomic selection schemes, as well as furthering our understanding of technological processing aspects of cows' milk.

A post-GWAS confirming the SCD gene associated with milk medium- and long-chain unsaturated fatty acids in Chinese Holstein population.

The stearoyl-CoA desaturase (delta-9-desaturase) gene encodes a key enzyme in the cellular biosynthesis of monounsaturated fatty acids. In our initial genome-wide association study (GWAS) of Chinese Holstein cows, 19 SNPs fell in a 1.8-Mb region (20.3-22.1 Mb) on chromosome 26 underlying the SCD gene and were highly significantly associated with C14:1 or C14 index. The aims of this study were to verify whether the SCD gene has significant genetic effects on milk fatty acid composition in dairy cattle. By resequencing the entire coding region of the bovine SCD gene, a total of six variations were identified, including three coding variations (g.10153G>A, g.10213T>C and g.10329C>T) and three intronic variations (g.6926A>G, g.8646G>A and g.16158G>C). The SNP in exon 3, g.10329C>T, was predicted to result in an amino acid replacement from alanine (GCG) to valine (GTG) in the SCD protein. An association study for 16 milk fatty acids using 346 Chinese Holstein cows with accurate phenotypes and genotypes was performed using the mixed animal model with the proc mixed procedure in sas 9.2. All six detected SNPs were revealed to be associated with six medium- and long-chain unsaturated fatty acids (P = 0.0457 to P < 0.0001), specifically for C14:1 and C14 index (P = 0.0005 to P < 0.0001). Subsequently, strong linkage disequilibrium (D' = 0.88-1.00) was observed among all six SNPs in SCD and the five SNPs (rs41623887, rs109923480, rs42090224, rs42092174 and rs42091426) within the 1.8-Mb region identified in our previous GWAS, indicating that the significant association of the SCD gene with milk fatty acid content traits reduced the observed significant 1.8-Mb chromosome region in GWAS. Haplotype-based analysis revealed significant associations of the haplotypes encompassing the six SCD SNPs and one SNP (rs109923480) in a GWAS with C14:1, C14 index, C16:1 and C16 index (P = 0.0011 to P < 0.0001). In summary, our findings provide replicate evidence for our previous GWAS and demonstrate that variants in the SCD gene are significantly associated with milk fatty acid composition in dairy cattle, which provides clear evidence for an increased understanding of milk fatty acid synthesis and enhances opportunities to improve milk-fat composition in dairy cattle.

Effect of polymorphisms in the CSN3 (κ-casein) gene on milk production traits in Chinese Holstein Cattle.

This study was designed to evaluate significant associations between single nucleotide polymorphisms (SNPs) and milk composition and milk production traits in Chinese Holstein cows. Six SNPs were identified in the κ-casein gene using pooled DNA sequencing. The identified SNPs were genotyped by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) methods from 507 individuals. Out of six, we identified three non-synonymous SNPs (g.10888T>C, g.10924C>A and g.10944A>G) that changed in the protein product. SIFT (Sorting_Intolerant_From_Tolerant) prediction score (0.01) demonstrated that protein changed Isoleucine > Threonine (g.10888T>C) will affect the phenotypes. Significant associations between identified SNPs and three yield traits (milk, protein and fat) and two composition traits (fat and protein percentages) were found whereas it did not reach significance for fat percentage in haplotypes association. Importantly, the significant SNPs in our results showed a large proportion of the phenotypic variation of milk protein yield and concentration. Our results suggest that CSN3 is an important candidate gene that influences milk production traits, and identified polymorphisms and haplotypes could be used as a genetic marker in programs of marker-assisted selection for the genetic improvement of milk production traits in dairy cattle.

Effect of FASN gene on milk yield and milk composition in the Chinese Holstein dairy population.

Fatty acid synthase (FASN) is a multifunctional protein that catalyzes de novo synthesis of fatty acids in cells. It plays a key role in the lipid biosynthesis as well as in the general metabolism of all living animals. We herein investigated polymorphisms of FASN. As a result, six single nucleotide polymorphisms (SNPs) were found and then genotyped in 752 Chinese Holstein cows. It was found that g.17924A>G was non-synonymous, g.13965 C>T, g.16907 T>C and g.18663T>C were synonymous mutations and two other two SNPs, g.8948 C>T (ss491228481) and g.14439T>C (rs133498277), were in intronic sequences of the gene. All such identified SNPs were found to be associated with milk yield and composition traits (P = 0.0441 to <0.0001). Significant additive and allele substitution effects were observed for three yield traits at all six loci as well (P < 0.05 to <0.01). Complete linkage disequilibrium among the five SNPs, with the exception of g.8948 C>T, was observed.

Synchronous development of Eimeria tenella in chicken caeca and utility of laser microdissection for purification of single stage schizont RNA.

Eimeria tenella is recognized worldwide as a significant pathogen in the poultry industry. However, a lack of methods for isolating developing schizonts has hindered the use of transcriptome analyses to discover novel and developmentally regulated genes. In the present study, we characterized the long-term successive development of E. tenella in infected chicken caeca and assessed the utility of laser microdissection (LMD) for the isolation of schizont RNA. Developmental stages, including those of the first, second, and third-generation schizonts and gametocytes, were synchronous. Using LMD, only the mature second-generation schizonts were successfully excised from the lamina propria, and non-degraded RNA was purified from the schizonts. E. tenella-specific genes were amplified by reverse transcription polymerase chain reaction (RT-PCR). These results augment our understanding of the E. tenella life cycle, and reveal LMD as a potentially useful tool for gene expression analyses of the intracellular stages of E. tenella.

Genetic effects of stearoyl-coenzyme A desaturase (SCD) polymorphism on milk production traits in the Chinese dairy population.

Stearoyl-CoA desaturase (SCD) is a multifunctional complex enzyme important in the cellular biosynthesis of fatty acids. The present study was to investigate the association of the SCD gene with milk production traits in dairy cattle. Two single nucleotide polymorphisms (SNPs) (g.6926A>G and g.8646A>G) in introns 3 and 4, and three SNPs (g.10153A>G, g.10213T>C and g.10329C>T) in exon 5 were identified with pooled DNA sequencing and genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry assay in 752 Chinese Holstein cows. Polymorphism g.10329C>T was predicted to result in an amino acid replacement from alanine to valine in the SCD protein. With a mixed animal model, the significant associations of the five SNPs with 305-day milk, fat and protein yields and protein percentage were determined. We further demonstrated cows with heterozygous genotypes (A/G or C/T) had highest 305 day milk yield, fat yield, protein yield and lowest protein percentage. Heterozygous cows with genotype AG at the g.6926A>G locus showed the greatest milk yield (P < 0.0001), fat yield (P < 0.0001) and protein yield (P < 0.0001) among other heterozygous genotypes at any of the loci. Dominance effects of all identified SNPs on milk, fat and protein yields and protein percentage were significant. Moreover, significant allele substitution effects at g.6926A>G locus on milk yield and at g.10213T>C on protein yield were observed. Five-locus haplotypes and strong linkage disequilibrium (D' > 0.9) between the five SNPs were also observed. The results suggest that identified polymorphisms could be potential genetic markers to improve the production performance of Chinese Holstein.

Human thelaziasis in Bangladesh.

Very few cases of Human Thelaziasis are reported worldwide. This is the first case of its kind from Bangladesh. A 58 years old man was admitted to Ophthalmology department of Mymensingh Medical College Hospital, Mymensingh, with itching, redness, foreign body sensation, lacrimation & filamentary discharge from right eye (R/E). He had visual acuity <6/60, conjunctival congestion & advanced bi-headed pterygium of R/E. After exposure of R/E ball with universal eye's speculum, a thin white nematode was found into the right lower conjunctival fornix. It was taken out by a plain forceps, placed into a bottle containing Hartman's solution & immediately sent to Microbiology department of Mymensingh Medical College for proper identification. Subsequently with the joint collaboration & detailed examination by the Parasitology department of Bangladesh Agricultural University (BAU), Mymensingh, the nematode was identified as an adult Thelazia callipaeda worm.

Monitoring the health and production of household Jinding ducks on Hatia Island of Bangladesh.

Duck rearing is an important component of sustainable living in poor rural communities, especially as a source of subsistence. A study was conducted on 118 households (N = 1,373 Jinding ducks, Anas platyrhynchus) from December 2002 to February 2004 on Hatia Island in Bangladesh with the aim of identifying the factors that limit the health and production of Jinding ducks. Overall duck mortality was 29.3%, with disease (19.7%) being a more significant factor than predation (9.6%; p = 0.001). Duck mortality also varied significantly among study zones (p < 0.001). Common diseases were duck plague (21.1%) and duck cholera (32.1%). Helminth infection was prevalent, with endemic trematode (Prosthogonimus spp., Trichobilharzia spp., Echinostoma spp.) and nematode (Cyathostoma bronchialis, Amidostomum anseris, Heterakis gallinarum, Capillaria spp., and Echinuria spp.) infections and epidemic cestode infections due to Hymenolepsis setigera. The median egg production rate per duck per household was 93 for a 6-month laying period. The odds of diminished egg production (average ≤ 93 eggs per duck per household for a 6-month laying period) was 25.4 times higher in ducks that were kept in traditional duck houses (p < 0.001) and 14.2 times higher in ducks that experienced delays in the onset of sexual maturity (days 191 and 280; p < 0.001). Ducks that were provided snails for a shorter period of time over the laying period were 18.2 times more likely to produce fewer eggs than their longer fed peers (p = 0.002). In conclusion, duck mortalities due to diseases and predation and parasitic infections appear to be common constraints on household duck production on Hatia Island. Additionally, improving duck housing and providing longer nutritional supplementation with snails increased the production capabilities of household-raised Jinding ducks on Hatia Island.

A DNA sequence-based study of the Schistosoma indicum (Trematoda: Digenea) group: population phylogeny, taxonomy and historical biogeography.

Partial (DNA) sequences were collected for 2 mitochondrial loci (Srrna and Lrrna, the rrnS and rrnL rRNA genes respectively) for Schistosoma indicum group species from 4 Southeast Asian countries. The samples included 7 populations, 4 of which were previously unstudied. In 11 cases the combination of locus and population was new. The aim of the study was to provide a phylogeny based on new independent data and multiple populations (earlier studies had mostly used a common set of field samples or laboratory lines) and to examine interrelationships and phylogeography within this species group. Paraphyly of the S. indicum group was confirmed, as was the basal position of Schistosoma incognitum in the Schistosoma phylogeny. Southeast Asian Schistosoma spindale and S. incognitum populations were shown to fall into their respective con-specific cohesive groupings. Estimated divergence times for these taxa were shown to be related to Pleistocene changes in sea level and the radiation of definitive host groups. A revised phylogeographical model is proposed in the light of these findings.

Molecular characterization of a blood-induced serine carboxypeptidase from the ixodid tick Haemaphysalis longicornis.

Ticks feed exclusively on blood to obtain their nutrients, but the gene products that mediate digestion processes in ticks remain unknown. We report the molecular characterization and possible function of a serine carboxypeptidase (HlSCP1) identified in the midgut of the hard tick Haemaphysalis longicornis. HlSCP1 consists of 473 amino acids with a peptidase S10 family domain and shows structural similarity with serine carboxypeptidases reported from other arthropods, yeasts, plants and mammals. Endogenous HlSCP1 is strongly expressed in the midgut and is supposed to localize at lysosomal vacuoles and on the surface of epithelial cells. Endogenous HlSCP1, identified as a 53 kDa protein with pI value of 7.5, was detected in the membrane/organelle fraction isolated from the midgut, and its expression was upregulated during the course of blood-feeding. Enzymatic functional assays revealed that a recombinant HlSCP1 (rHlSCP1) expressed in yeast efficiently hydrolyzed the synthetic substrates specific for cathepsin A and thiol protease over a broad range of pH and temperature values. Furthermore, rHlSCP1 was shown to cleave hemoglobin, a major component of the blood-meal. Our results suggest that HlSCP1 may play a vital role in the digestion of the host's blood-meal.

Fluoride exposure inhibits protein expression and enzyme activity in the lung-stage larvae of Ascaris suum.

Sodium fluoride (NaF) is an anion that has been previously shown to block the moulting process of Ascaris suum larvae. This study describes moulting and development-specific protein expression profiles of A. suum lung-stage L3 (AsLL3) following NaF exposure. AsLL3s cultured in the presence or absence of NaF were prepared for protein analysis using two-dimensional (2D) electrophoresis. NaF exposure inhibited at least 22 proteins in AsLL3 compared with moulted larvae (i.e. AsLL4). A further comparison of AsLL4 with those of pre-cultured AsLL3 and NaF-exposed AsLL3 revealed 8 stage-specifically and 4 over-expressed proteins. Immunoblot analysis revealed an inhibition by NaF of 19 immunoreactive proteins. Enzyme assay and immunochemical data showed an inhibition of the moulting-specific inorganic pyrophosphatase activity by 41% and a decreased expression in NaF-treated larvae, indicating its significance in the moulting process. A protein spot associated with NaF inhibition was isolated and identified by peptide mass spectrometry and bioinformatics approaches to be a member of 3-hydroxyacyl-CoA dehydrogenase/short-chain dehydrogenase enzyme families. These results have implications for the identification of proteins specific to the moulting process as potential chemotherapeutic targets.

The V kappa III subgroup light chain proteins in AL amyloidosis & autoimmune diseases.

BACKGROUND & OBJECTIVES: Light chain associated amyloidosis (AL) is characterized by extracellular deposition of immunoglobulin light chain and its fragments. In vitro and in vivo studies have shown that some light chains are nonamyloidogenic and nonnephrotoxic, whereas others are potentially amyloidogenic. Some light chains are prone to be deposited as rheumatoid materials, and also as nodular amorphous aggregates (light chain deposition diseases). These findings suggest that specific sequence element(s) may control the various kinds of light chain associated diseases. In this study we tried to identify such sequence element(s). METHODS: Two Bence Jones proteins (BJPs), NIG93 and NIG2 of subgroup V kappa III, were characterized and compared with other members of the same subgroup whose sequences are available in the data base. RESULTS: Both NIG93 and NIG2 proteins had sequences characteristics of V kappa IIIa as distinguished from V kappa IIIb, subsubgroup proteins. They also contained several novel substitutions, such as Met-37, Leu-40, Val-58, and IIe-85 in NIG93, and Val-2, His-29, Arg-50, and Ile-72 in NIG2. The data accumulated at present indicate that all members of the V kappa IIIa subsubgroup are related to either AL amyloidosis or rheumatoid arthritis, whereas the V kappa IIIb proteins are related to autoimmune diseases. INTERPRETATION & CONCLUSION: These observations indicate that subgroup-specific residues might be critical for light chain pathogenesis, at least for the V kappa III proteins. Point mutations within these proteins may be another structural element controlling their conformation as well as their pathogenic aggregation.

NACP/alpha-synuclein and tau constitute two distinctive subsets of filaments in the same neuronal inclusions in brains from a family of parkinsonism and dementia with Lewy bodies: double-immunolabeling fluorescence and electron microscopic studies.

The co-localization of NACP/alpha-synuclein and tau epitopes was examined in the brain stem and hippocampal formation in two patients from a family of autosomal dominant parkinsonism and dementia with Lewy bodies (LBs) without two reported missense mutations in the NACP gene. Double-labeling immunofluorescence study revealed that some brain stem LBs, cortical LBs, pale bodies, Lewy-related neurites, and neurofibrillary tangles expressed both NACP epitopes and the PHF tau AT8 epitope. Double-immunolabeling electron microscopy demonstrated that the NACP antibody selectively labeled 9- to 13-nm-thick straight filaments (LB filaments), whereas AT8 recognized twisted tubules with 80-to 100-nm-interval constrictions in the same neuronal inclusions. We show that NACP and tau aggregate into different filamentous components even if both proteins are incorporated into the same inclusions.

Structural relationship of kappa-type light chains with AL amyloidosis: multiple deletions found in a VkappaIV protein.

Two amyloidogenic Bence Jones proteins (Am37 VkappaIV and NIG1 VkappaI) and one non-amyloidogenic protein (NIG26 VkappaIII) were characterized. The protein Am37 had four deletions when compared with the translated germ-line gene sequence: two Ser residues following position 27 (27e, 27f) in CDR1 and two amino acids Pro-44, and Tyr-49 in FR2 were deleted. A strictly conserved salt-bridge-forming amino acid, Asp-82, was replaced by the hydrophobic residue Leu. In a comparative study of amyloidogenic and non-amyloidogenic proteins, five amino acids (Ser-10, Ala-13, Ser-65, Gln-90, and Ile-106) were found to be unique to NIG1 and several other amyloidogenic proteins. Additional substitutions also occur within these proteins. These substitutions might be significant in altering protein folding as well as in contributing to their aggregation as amyloid fibrils.

Structural relationship of lambda-type light chains with AL amyloidosis.

Three human amyloidogenic Bence Jones proteins, NIG76 VlambdaII, NIG204 VlambdaI, and NIG250 VlambdaV, were characterized. In a comparative study, three amino acids, Ser-25a, Thr-68, and Val-95, were found to be common to amyloidogenic proteins of the VlambdaII subgroup. NIG204 had an insertion of Pro residue following position 30 (30a). Proteins having an insertion at this position are invariantly amyloidogenic. NIG250 had a characteristic VlambdaV VL domain, with Mcg+ and KERN+ CL domain isotypes. Following the protein DEL, this is the second example of this subgroup. No common residue is found in the other subgroup proteins but unique substitutions do occur. It would seem that any substitution that causes an alteration in the protein conformation may lead to its being more prone to association with the amyloid processes.