Re-assessments of four topics which interested Hopkins - 2. Tryptophan

1962 ◽  
Vol 156 (964) ◽  
pp. 299-306
Keyword(s):  
Amino Acid ◽  
Chemical Composition ◽  
Essential Amino Acid ◽  
Protein Molecule ◽  
The Body ◽  
Protein Source ◽  
Bacterial Degradation ◽  
Survival And Growth ◽  
Sixtieth Anniversary ◽  
Correct Structure

The centenary of Hopkins’s birth is also the sixtieth anniversary of the isolation of tryptophan by Hopkins & Cole (1901), and if in their paper they were in error over its constitution their work was, according to Harris (1949), one of the first to employ bacterial degradation as an aid to establishing chemical composition. The correct structure was established by Ellinger & Flamand in 1907. By 1906 Wilcock & Hopkins had shown that a particular protein zein failed as a protein source to support life and that the presence of a group in a protein molecule, viz. tryptophan, was a dietary essential and £served some purpose in the body other than forming tissue or supplying energy’. The concept and importance in nutrition of the essential amino acid thus emerges in the same year that we have Hopkins’s prophecy that ‘the factors whose deficiency were responsible for diseases such as scurvy and rickets were certainly of the kind which comprises the minimal qualitative factors which must be added to artificially refined diets to enable them to support mammalian survival and growth’: the tryptophan story was later to lead into this other realm of his activity.

scholarly journals Protease Responsive Essential Amino-Acid Based Nanocarriers for Near-Infrared Imaging

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anshu Kumari ◽  
Kalpana Kumari ◽  
Sharad Gupta
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Essential Amino Acid ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Average Diameter ◽  
The Body ◽  
Free Form ◽  
Theranostic Agents

AbstractDelivery of the theranostic agents with effective concentration to the desired sites inside the body is a major challenge in disease management. Nanotechnology has gained attention for the delivery of theranostic agents to the targeted location. The use of essential amino-acid based homopolymers for the synthesis of biocompatible and biodegradable nanoparticles (NPs) could serve as a nanocarrier for delivery applications. In this study, poly-l-lysine (PLL) and salts were used to fabricate the NPs for the delivery of exogenous contrast agents. Here, indocyanine green (ICG) was encapsulated within these NPs, and a simple two-step green chemistry-based self-assembly process was used for the fabrication. The morphological and biochemical characterizations confirm the formation of ICG encapsulating spherical PLL NPs with an average diameter of ~225 nm. Further, a detailed study has been carried out to understand the role of constituents in the assembly mechanism of PLL NPs. Our results show a controlled release of the ICG from PLL NPs in the presence of the proteolytic enzyme. In-vitro cellular studies suggest that the PLL NPs were readily taken up by the cells showing their superior delivery efficiency of ICG in comparison to the free-form of the ICG.

Use of protein sources alternative to fish meal in diets with amino acids supplementation for the European eel (Anguilla anguilla)

1998 ◽  
Vol 66 (1) ◽  
pp. 285-292 ◽  
Author(s):  
M. García-Gallego ◽  
H. Akharbach ◽  
M. de la Higuera
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Fish Meal ◽  
Anguilla Anguilla ◽  
Essential Amino Acids ◽  
Protein Source ◽  
European Eel ◽  
Protein Sources ◽  
Meat Meal

AbstractThis experiment was conducted to test two different protein sources as alternatives to the commonly used fish meal (FM) in the diet of the European eel (Anguilla anguilla). Six experimental diets were tested in three replicated lots of European eels. All diets contained the same protein and energy content (ca, 300 g crude protein per kg dry matter and 18·5 MJ/kg, respectively) but differed in the nature of the protein source: FM was the only protein source in the control diet and was fully or partially (0–5: 0–5) replaced by meat meal (MM) or sunflower meal (SFM) in four other diets; a sixth diet included SFM as the only protein source but was supplemented with several essential amino acids. Food intake, fish growth and several indices of diet and protein utilization were measured. MM clearly was the poorest protein source while SFM could replace, at least 0·5 of the FM with no significant reduction in performance. In addition, the European eel was able to utilize the supplement of essential amino acids. The full-SFM diet was improved significantly when supplemented and results were not statistically different from the control FM-based diet. Overall, a good correlation was found between the results of each diet and the respective essential amino acid index, calculated using as reference the essential amino acid requirements previously defined for another eel species, Anguilla japonica. This index could be used as a reliable measure for an a priori evaluation of alternative protein sources to be included in commercial foods for eels.

scholarly journals Chemical composition of the leaves of tea bush (Ocimum gratissium L.)

2015 ◽  
Vol 50 (2) ◽  
pp. 93-108
Author(s):  
EI Adeyeye ◽  
MA Oyarekua
Keyword(s):  
Fatty Acid ◽  
Amino Acid ◽  
Chemical Composition ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Essential Amino Acid ◽  
Quality Criteria ◽  
Quality Parameters ◽  
Trace Minerals ◽  
Total Amino Acid

Tea bush leaves are important in the preparation of soups. Crude fat was 5.20g/100g. High value results (g/100g): protein (28.9), carbohydrate (36.2), ash (9.40), fibre (14.1); fatty acid (4.16g/100g) with energy value (154kJ/100g). High major minerals were: Ca, Mg, K and P, high trace minerals were: Fe, Cu, Mn and Zn. Mineral ratios within nutritional standards: Na/K, Ca/P and [K/(Ca + Mg)]. In amino acid composition, highest concentrated amino acid was Glu (11.0g/100g), second was Leu (7.65g/100g), total amino acid (87.2g/100g). Essential amino acid (with His) was 42.5g/100g (48.7%). Quality parameters obtained in the results: Leu/Ile (1.59), % Cys/TSAA (42.3), P-PER (2.49) and EAAI (1.18). On quality criteria, Lys was limiting in the three criteria used. Fatty acid had values of SFA (30.9%), MUFA (5.60%), PUFA (63.5%), PUFA/SFA (2.06), n-6/n-3 (1.52), EPA/DHA (1.39). Total phospholipids (44.1mg/100g) with phosphatidylcholine (15.9), phosphatidylinostitol (14.9) predominating. Cholesterol was 0.00mg/100g, sitosterol was 26.3mg/100g (61.5%).Bangladesh J. Sci. Ind. Res. 50(2), 93-108, 2015

scholarly journals Chemical Composition of Serendipity Berry (Dioscoreophyllum cumminsii) and Miracle Fruit (Thaumatococcus daniellii)

2020 ◽  
pp. 10-15
Author(s):  
A. Ojo ◽  
V. N. Enujiugha ◽  
H. N. Ayo- Omogie ◽  
O. A. Abiodun
Keyword(s):  
Amino Acid ◽  
Chemical Composition ◽  
Essential Amino Acid ◽  
Chemical Properties ◽  
Amino Acid Content ◽  
Appreciable Amount ◽  
Total Amino Acid ◽  
Crude Fibre ◽  
Amino Acid Contents ◽  
Thaumatococcus Daniellii

Aims: To determine the chemical composition of serendipity berry (Dioscoreophyllum cumminsii) and miracle fruit (Thaumatococcus daniellii). Study Design: The mean and standard deviation of the data obtained were  analyzed. Place and Duration of Study: Samples were prepared in Department of Food Science and Technology, Osun State Polytechnic, between November 2018 and December 2019. Methodology: Chemical properties of two natural sweeteners namely the miracle fruit (Thaumatococcus danielli) and serendipity berry (Dioscoreophyllum cumminsii) were studied in this work. The fresh fruits were obtained from a farm, sorted, washed and the tissues were scraped, dried in the oven at 45°C for 12 hrs, milled and packed in airtight plastic containers. Proximate, vitamins and amino acid contents of the sweeteners were determined. Results: The results revealed that the protein contents of miracle fruit and serendipity berry were 75.57% and 62.54% respectively. Moisture contents of the sweeteners ranged from 56.95-58.33% while ash contents ranged from 19.33-22.90%. The sweeteners had low carbohydrate and lipid contents. Crude fiber was not detected in miracle fruit but serendipity berry had crude fibre of 5.38%. The fruits had β-carotene contents ranging from 8.44 mg/100 g and 23.00 mg/100 g, vitamin C (20.40 mg/100 g and 22.01 mg/100 g) and vitamin D (17.02 mg/100 g and 19.02 mg/100 g) in miracle fruit and serendipity berry respectively. However, low values were recorded for vitamin E 0.55 mg/100 g and 0.89 mg/100 g in miracle fruit and serendipity berry respectively. The fruits had appreciable amount of essential amino acid which was above 50% of the total amino acid content. Miracle fruit had 51.96% and serendipity berry had 58.07% of the essential amino acid. Aromatic essential amino were 10.78 and 12.79% in miracle fruits and serendipity respectively. Conclusion: This study showed that the two natural sweeteners are good source of essential nutrients and could be used as food supplements in our diet.

scholarly journals Targeted Degradation of Proteins — The Ubiquitin System

2021 ◽  
Vol 9 ◽  
Author(s):  
Aaron Ciechanover
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chemical Composition ◽  
Nobel Prize ◽  
Building Blocks ◽  
Spoken Language ◽  
The Body ◽  
Cancer Center ◽  
Ubiquitin System ◽  
Specific Order

Proteins are the engines of all forms of life, for humans and for all the plant and animal kingdoms. Proteins are used both to build organs (such as bones, muscles, and skin) and to perform bodily functions. These functions range from digestion (processing food and converting it into energy), to enabling movement and sensation (sight and hearing), to protecting the body from foreign invaders with our antibodies, which are also proteins. What are proteins? They can be compared to words in a language that contains letters. In the Hebrew alphabet, there are 26 letters out of which countless words can be composed. But when we write, we use just a fraction of these infinite options, with the average number of letters in a word ranging between 3 and 8. The biological “protein alphabet” is comprised of 20 “letters” called amino acids, which are the building blocks of the proteins that make up the body. Proteins are chains of amino acid, linked together in a specific order governed by the DNA. Unlike the words of a spoken language, the average protein consists of hundreds of amino acids. The extensive length of proteins and the chemical composition of the amino acids make proteins sensitive to many factors, such as high temperatures, radiation, and chemicals. All these factors damage proteins and alter their fragile structures, negatively affecting how they function. When proteins are damaged or when they finish performing their functions and are no longer needed, the body breaks them down. With my doctoral adviser, Prof. Avram Hershko, and our research collaborator, Prof. Irwin Rose from the Fox Chase Cancer Center in Philadelphia, we discovered the mechanism responsible for targeted degradation of proteins in cells. This degradation can recognize damaged proteins or proteins that are not needed anymore, while leaving intact the “healthy,” functional ones. This mechanism is called the ubiquitin system after its principal protein, ubiquitin, which was the first protein we discovered in the system. Ubiquitin’s role is to tag undesirable proteins so that the cell’s “grinder” can recognize them and break them down, enabling the cell to function normally. In this article, we will explain the story of proteins and the ubiquitin system that we discovered in a study that earned us, among other prizes, the Nobel Prize in Chemistry in 2004.

scholarly journals Effects of dietary butyrate supplementation and crude protein level on carcass traits and meat composition of broiler chickens

2019 ◽  
Vol 62 (2) ◽  
pp. 527-536
Author(s):  
Gábor Mátis ◽  
Janka Petrilla ◽  
Anna Kulcsár ◽  
Henry van den Bighelaar ◽  
Bart Boomsma ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chemical Composition ◽  
Sodium Butyrate ◽  
Essential Amino Acid ◽  
Crude Protein ◽  
Feed Additive ◽  
Meat Production ◽  
Breast Meat ◽  
Meat Composition ◽  
Femoral Muscle

Abstract. The short-chain fatty acid butyrate, either in unprotected or protected form, is widely applied as a growth-promoting feed additive in poultry nutrition; however, its possible effects on the carcass composition of broilers have not been fully elucidated. Further, lowering dietary crude protein (CP) levels is an important issue in poultry farming, contributing to ecologically beneficial lower nitrogen excretion. The main aims of this study were to test how unprotected and protected forms of butyrate and decreased dietary CP content with essential amino acid (lysine, methionine, threonine, tryptophan) supplementation (“LP-EAA” diet) affect carcass parameters and the chemical composition of muscles in broilers. Ross 308 chickens were randomized to seven groups (n=10/group) receiving adequate CP-containing (normal protein, “NP”) or LP-EAA diets, both supplemented with or without unprotected sodium butyrate, and NP diets with different forms of protected sodium butyrate. Carcass traits were measured, and the chemical composition of pectoral and femoral muscles was analyzed at the age of 6 weeks. Carcass weight was significantly increased by the LP-EAA diet and all protected butyrate types tested, while the relative breast meat yield was significantly higher in LP-EAA than NP groups and in both unprotected and protected butyrate-supplemented chickens compared to controls. The protein content of the femoral muscle was significantly decreased, but its lipid content was significantly elevated by the LP-EAA diet and by all types of butyrate addition. However, no changes were detected in the chemical composition of pectoral muscle. In conclusion, breast meat production can be effectively stimulated by dietary factors, such as by reducing dietary CP content with essential amino acid supplementation and by applying butyrate as a feed additive, while its chemical composition remains unchanged, in contrast to the femoral muscle. The aforementioned nutritional strategies seem to be the proper tools to increase carcass yield and to alter meat composition of broilers, contributing to more efficient poultry meat production.

Dietary intake of tryptophan tied emotion-related impulsivity in humans

2019 ◽  
pp. 1-8 ◽  
Author(s):  
Florian Javelle ◽  
Descartes Li ◽  
Philipp Zimmer ◽  
Sheri L. Johnson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Essential Amino Acid ◽  
Food Habits ◽  
Psychological Disorder ◽  
Serotonin Synthesis ◽  
Amino Acid Tryptophan ◽  
Pass Through ◽  
Three Factor

Abstract. Emotion-related impulsivity, defined as the tendency to say or do things that one later regret during periods of heightened emotion, has been tied to a broad range of psychopathologies. Previous work has suggested that emotion-related impulsivity is tied to an impaired function of the serotonergic system. Central serotonin synthesis relies on the intake of the essential amino acid, tryptophan and its ability to pass through the blood brain barrier. Objective: The aim of this study was to determine the association between emotion-related impulsivity and tryptophan intake. Methods: Undergraduate participants (N = 25, 16 women, 9 men) completed a self-rated measure of impulsivity (Three Factor Impulsivity Index, TFI) and daily logs of their food intake and exercise. These data were coded using the software NutriNote to evaluate intakes of tryptophan, large neutral amino acids, vitamins B6/B12, and exercise. Results: Correlational analyses indicated that higher tryptophan intake was associated with significantly lower scores on two out of three subscales of the TFI, Pervasive Influence of Feelings scores r =  –.502, p < . 010, and (lack-of) Follow-Through scores, r =  –.407, p < . 050. Conclusion: Findings provide further evidence that emotion-related impulsivity is correlated to serotonergic indices, even when considering only food habits. It also suggests the need for more research on whether tryptophan supplements might be beneficial for impulsive persons suffering from a psychological disorder.

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