scholarly journals Factors Influencing Proteolysis and Protein Utilization in the Intestine of Pigs: A Review

Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3551
Author(s):  
Alina Kurz ◽  
Jana Seifert

Pigs are among the most important farm animals for meat production worldwide. In order to meet the amino acid requirements of the animals, pigs rely on the regular intake of proteins and amino acids with their feed. Unfortunately, pigs excrete about two thirds of the used protein, and production of pork is currently associated with a high emission of nitrogen compounds resulting in negative impacts on the environment. Thus, improving protein efficiency in pigs is a central aim to decrease the usage of protein carriers in feed and to lower nitrogen emissions. This is necessary as the supply of plant protein sources is limited by the yield and the cultivable acreage for protein plants. Strategies to increase protein efficiency that go beyond the known feeding options have to be investigated considering the characteristics of the individual animals. This requires a deep understanding of the intestinal processes including enzymatic activities, capacities of amino acid transporters and the microbiome. This review provides an overview of these physiological factors and the respective analyses methods.

1955 ◽  
Vol 102 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Harry Eagle

The amino acid requirements of a human uterine carcinoma cell (HeLa strain) have been defined. The 12 compounds previously found to be essential for the growth of a mouse fibroblast proved similarly essential for this human epithelial cell. They included arginine, cyst(e)ine, histidine, and tyrosine, in addition to the eight amino acids required for nitrogen balance in man (isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine). Only the L-amino acids were active; the D-enantiomorphs had no demonstrable effect at physiologic concentrations. The minimum concentrations required for survival and limited growth varied from 0.003 µM per ml. for L-tryptophan, to 0.1 µM per ml. for L-lysine. The concentrations permitting optimum growth similarly varied from 0.01 µM per ml. for tryptophan, to 0.1 µM per ml. for leucine, isoleucine, threonine, lysine, and valine. The latter optimum concentrations of the individual amino acids were closely correlated with their serum levels. With at least six of the amino acids, high concentrations, in the range 1 to 10 µM per ml., caused a definite growth inhibition. In the absence of a single essential amino acid, degenerative changes occurred in the cells, culminating in their death and dissolution. In the early stages, however, these degenerative changes could be reversed by the restoration of the missing component.


2012 ◽  
Vol 2 (4) ◽  
pp. 107 ◽  
Author(s):  
Chidi U. Igwe ◽  
Okey A. Ojiako ◽  
Ken C. Anugweje ◽  
Linus A. Nwaogu ◽  
Cosmas O. Ujowundu

Background: Increasing incidence of malnutrition occasioned by high incidence of hunger, worsening food situation in the world, insufficient availability and high cost of animal protein sources, has necessitated extensive research into and use of alternative plant protein sources especially underexploited leguminous seeds.Methods: Flours from raw, boiled and fermented seeds of Prosopis africana and Ricinus communis were evaluated for crude protein and amino acid (AA) profiles, and their protein qualities determined. Results: Fermentation improved the protein contents of raw seeds of P. africana and R. communis by 18.70% and 3.95% respectively. In the raw and fermented P. africana seeds, glutamate at 132.60 ± 1.30 and 182.70 ± 3.02 mg/g crude protein (mg/gcp) was the most abundant amino acid (AA), while leucine (62.80 ± 0.60 and 79.50 ± 2.01 mg/gcp) was the most concentrated essential amino acid (EAA). Aspartate (151.90 ± 2.01 and 170.10 ± 2.00 mg/gcp) and arginine (72.80 ± 2.01 and 78.60 ± 2.00 mg/gcp) were the most concentrated and abundant non-essential amino acid (NEAA) and EAA in the raw and fermented samples of R. communis respectively. The total AA concentrations (mg/gcp) of raw and fermented P. africana were 733.00 and 962.60 respectively, while those of R. communis were 823.50 and 894.10 respectively. The total EAA contents (mg/gcp) for P. africana were 311.00 (raw) and 404.50 (fermented), and for R. communis; 401.10 (raw) and 430.30 (fermented). Threonine was the limiting EAA in raw and fermented P. africana, whereas lysine was the limiting EAA in R. communis raw sample. Fermentation significantly (p<0.05) increased the individual AA compositions of P. africana and R. communis by 94% and 53% respectively, while boiling reduced these parameters significantly (p<0.05) by 47% and 82% respectively.Conclusion: P. africana and R. communis seeds are potentially important plant sources of protein and essential amino acids, and so could be of great importance in combating malnutrition and food security problems generally.Key words: Amino acid score; condiments; crude protein; fermentation; legumes; nutrition


1996 ◽  
Vol 76 (06) ◽  
pp. 0993-0997
Author(s):  
Zhao-Yan Li ◽  
Xiao-Wei Wu ◽  
Tie-Fu Yu ◽  
Eric C-Y Lian

SummaryBy means of CM-Sephadex C-25, DEAE-Sephadex A-50, Sephadex G-200, and Sephadex G-75 chromatographies, a lupus anticoagulant like protein (LALP) from Agkistrodon halys brevicaudus was purified. On SDS-PAGE, the purified LALP had a molecular weight of 25,500 daltons under non-reducing condition and 15,000 daltons under reducing condition. The isoelectric point was pH 5.6. Its N terminal amino acid sequencing revealed a mixture of 2 sequences: DCP(P/S)(D/G)WSSYEGH(C/R)Q(Q/K). It was devoid of phospho-lipaseA, fibrino(geno)lytic, 5′-nucleotidase, L-amino acid oxidase, phosphomonoesterase, phosphodiesterase and thrombin-like activities, which were found in crude venom. In the presence of LALP, PT, aPTT, and dRVVT of human plasma were markedly prolonged and its effects were concentration-dependent but time-independent. The inhibitory effect of LALP on the plasma clotting time was enhanced by decreasing phospholipid concentration in TTI test. The individual clotting factor activity was not affected by LALP when higher dilutions of LALP-plasma mixture were used for assay. Russell’s viper venom time was shortened when high phospholipid confirmatory reagent was used. Therefore, the protein has lupus anticoagulant property.


Law and World ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 115-144

The Article concerns the legal issues, connected with the situation, when a person (or group of people) disobey requirements of the Law or other State regulations on the basis of religious or nonreligious belief. The Author analyses almost all related issues – whether imposing certain obligation on individuals, to which the individual has a conscientious objection based on his/her religious beliefs, always represents interference with his/her religion rights, and if it does, then what is subject of the interference – forum integrum or forum externum; whether neutral regulation, which does not refer to religion issues at all, could ever be regarded as interference into someone’s religious rights; whether opinion or belief, on which the individual’s objection and the corresponding conduct is based, must necesserily represent the clear “manifest” of the same religion or belief in order to gain legal protection; what is regarded as “manifest” of the religion or other belief in general and whether a close and direct link must exist between personal conduct and requirements of the religious or nonreligious belief; what are the criteria of the “legitimacy” of the belief; to what extent the following factors should be taken into consideration : whether the personal conduct of the individual represents the official requirements of corresponding religion or belief, what is the burden which was imposed on the believer’s religious or moral feelings by the State regulation, also, proportionality and degree of sincerity of the individual who thinks that his disobidience to the Law is required by his/her religious of philosofical belief. The effects (direct or non direct) of the nonfulfilment of the law requirement (legal responsibility, lost of the job, certain discomfort, etc..) are relevant factors as well. By the Author, all these circumstances and factors are essencial while estimating, whether it arises, actually, a real necessity and relevant obligation before a state for making some exemptions from the law to the benefi t of the conscientious objectors, in cases, if to predict such an objection was possible at all. So, the issues are discussed in the prism of the negative and positive obligations of a State. Corresponding precedents of the US Supreme Court and European Human Rights Court have been presented and analysed comparatively by the Author in the Article. The Article contains an important resume, in which the main points, principal issues and conclusion remarks are delivered. The Author shows, that due analysis of the legal aspects typical to “Conscientious objection” is very important for deep understanding religious rights, not absolute ones, and facilitates finding a correct answer on the question – how far do their boundaries go?


Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 125
Author(s):  
Uğur Kahya ◽  
Ayşe Sedef Köseer ◽  
Anna Dubrovska

Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.


2021 ◽  
Vol 4 (3) ◽  
pp. 51
Author(s):  
Satish Kantipudi ◽  
Daniel Harder ◽  
Sara Bonetti ◽  
Dimitrios Fotiadis ◽  
Jean-Marc Jeckelmann

Heterodimeric amino acid transporters (HATs) are protein complexes composed of two subunits, a heavy and a light subunit belonging to the solute carrier (SLC) families SLC3 and SLC7. HATs transport amino acids and derivatives thereof across the plasma membrane. The human HAT 4F2hc-LAT1 is composed of the type-II membrane N-glycoprotein 4F2hc (SLC3A2) and the L-type amino acid transporter LAT1 (SLC7A5). 4F2hc-LAT1 is medically relevant, and its dysfunction and overexpression are associated with autism and tumor progression. Here, we provide a general applicable protocol on how to screen for the best membrane transport protein-expressing clone in terms of protein amount and function using Pichia pastoris as expression host. Furthermore, we describe an overexpression and purification procedure for the production of the HAT 4F2hc-LAT1. The isolated heterodimeric complex is pure, correctly assembled, stable, binds the substrate L-leucine, and is thus properly folded. Therefore, this Pichia pastoris-derived recombinant human 4F2hc-LAT1 sample can be used for downstream biochemical and biophysical characterizations.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 835
Author(s):  
Mohammadreza Mohammadabadi ◽  
Farhad Bordbar ◽  
Just Jensen ◽  
Min Du ◽  
Wei Guo

Farm-animal species play crucial roles in satisfying demands for meat on a global scale, and they are genetically being developed to enhance the efficiency of meat production. In particular, one of the important breeders’ aims is to increase skeletal muscle growth in farm animals. The enhancement of muscle development and growth is crucial to meet consumers’ demands regarding meat quality. Fetal skeletal muscle development involves myogenesis (with myoblast proliferation, differentiation, and fusion), fibrogenesis, and adipogenesis. Typically, myogenesis is regulated by a convoluted network of intrinsic and extrinsic factors monitored by myogenic regulatory factor genes in two or three phases, as well as genes that code for kinases. Marker-assisted selection relies on candidate genes related positively or negatively to muscle development and can be a strong supplement to classical selection strategies in farm animals. This comprehensive review covers important (candidate) genes that regulate muscle development and growth in farm animals (cattle, sheep, chicken, and pig). The identification of these genes is an important step toward the goal of increasing meat yields and improves meat quality.


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