The chemical composition of the cyst wall of the potato cyst-nematode, Heterodera rostochiensis

1. Cyst walls of the potato cyst-nematode (Heterodera rostochiensis Woll.) were isolated by sieving a suspension of crushed cysts. About 12mg. of dried cyst walls was obtained from 1000 cysts. 2. The cyst walls contained mainly protein (72%, calculated from nitrogen content). On acid hydrolysis about 77% of the cyst wall went into solution. Of 19 amino acids present, proline, glycine, and alanine were the most abundant, and made up about 50% by weight of the total amino acids. The amino acid composition suggested that collagen-like proteins predominated in the cyst wall and larval cuticle. 3. A small amount of glucosamine (1.5%) was present in the hydrolysates, but chitin was not detected in the cyst walls. 4. Other components of the cyst walls were lipid (2%), carbohydrate (0.5%) and a small amount of inorganic matter (ash, 5%). Polyphenols (2% by wt. of the cyst walls) occurred in the acid hydrolysates. The dark pigments of the cyst wall were not indole-containing melanins.     

The composition of the cyst wall of the beet cyst-nematode Heterodera schachtii

1. Cyst walls of the beet cyst-nematode (Heterodera schachtii Schmidt) were obtained by sieving a suspension of crushed cysts; about 15mg of dried cyst walls was obtained from 1000 cysts. 2. The cyst walls contained 68% protein calculated from nitrogen content. Glutamic acid, glycine, proline and hydroxyproline made up about 54% by weight of the amino acids obtained on acid hydrolysis. 3. Minor constituents of the cyst wall were hexosamine (3.3%), lipid (6%), carbohydrate (2%) and phenols (2%). The hexosamine was identified as galactosamine. 4. The cyst walls contained inorganic material (ash 17%), most of which was extractable with EDTA, but not with water. Major inorganic components were calcium and phosphorus (1.7% and 1.5% respectively, by weight). Carbon dioxide (about 1% by weight) was liberated from the cyst walls on acidification. 5. The cyst walls of H. schachtii and the potato cyst-nematode (Heterodera rostochiensis) contained different amounts of the same amino acids. They also differed in their inorganic content and in the nature of the hexosamine present.     

The structure of a glycopeptide isolated from the yeast cell wall

1. Glycopeptides containing mannose were extracted from isolated yeast cell walls by ethylenediamine and purified by treatment with Pronase and fractionation on a Sephadex column. 2. A glycopeptide that appeared homogeneous on electrophoresis and ultracentrifugation had a molecular weight of 76000, and contained a high-molecular-weight mannan and approx. 4% of amino acids. 3. The amino acid composition of the peptide was determined. It was rich in serine and threonine and also contained glucosamine. No cystine and methionine were detected. 4. The glycopeptide underwent a beta-elimination reaction when treated with dilute alkali at low temperatures. The reaction resulted in the release of mannose, mannose disaccharides and possibly other low-molecular-weight mannose oligosaccharides. During the beta-elimination reaction the dehydro derivatives of serine and threonine were formed. One of the linkages between carbohydrate and amino acids in the glycopeptide is an O-mannosyl bond from mannose and mannose oligosaccharides to serine and threonine. 5. After the beta-elimination reaction the bulk of the mannose in the form of the large mannan component was still covalently linked to the peptide. This polysaccharide was therefore attached to the amino acids by a linkage different from the O-mannosyl bonds to serine and threonine that attach the low-molecular-weight sugars. 6. Mannan was prepared from the glycopeptide and from the yeast cell wall by treatment of the fractions with hot solutions of alkali. The mannan contained aspartic acid and glucosamine and some other amino acids. The aspartic acid and glucosamine were present in equimolar amounts; the aspartic acid was the only amino acid present in an amount equivalent to that of glucosamine. Thus there is the possibility of a linkage between the mannan and the peptide via glucosamine and aspartic acid. 7. Mannose 6-phosphate was shown to be part of the mannan structure. Information about the structure of the mannan and the linkage of the glucosamine was obtained by periodate oxidation studies. 8. The glucosamine present in the glycopeptide could not be released by treatment with an enzyme preparation obtained from the gut of Helix pomatia. This enzyme released glucosamine from the intact cell wall. Thus there are probably at least two polymers containing glucosamine in the cell wall. 9. The biosynthesis of the mannan polymer in the yeast cell wall is discussed with regard to the two types of carbohydrate-amino acid linkages found in the glycoprotein.     

Electrophoretic isolation and partial characterization of a major secretory glycoprotein from the submandibular glands of the mouse

After either cholinergic or adrenergic stimulation of the submandibular glands of the mouse, a major protein of the incubation medium could be isolated by electrophoresis, designated the AM2 protein. About 5 per cent of the secreted proteins and 2.4 per cent of the secreted protein-bound sialic acid was recovered as the purified AM2 protein. The AM2 protein appeared to be electrophoretically pure in 7.5% polyacrylamide gel both at pH 8.9 and at pH 4.3. In sodium dodecyl sulfate-electrophoresis the molecular weight was estimated to be about 80 000 for the major component and about 40 000 for the minor component. By isoelectric focusing the isoelectric point has been determined to be 4.7. The amino acid analysis indicated Glx, Asx, Leu and Ala as the major amino acids, comprising 15.0, 10.6, 9.2 and 9.1 per cent of the amino acid residues, respectively. The ratio of the acidic amino acids and their amides (Glx plus Asx) to the basic amino acids (Lys plus Arg) was 2.2. The sugar analysis showed that the AM2 glycoprotein consists of 17.3 per cent of carbohydrate, with as major carbohydrate component glucosamine. The molar ratio of the sugars was Man : Gal : Glc : GlcNH2 : sialic acid = 2.3 : 1.0 : 4.7 : 9.8 : 2.9. Galactosamine could be detected as a trace component and fucose was not detectable.     

Concurrent protein synthesis is required for in vivo chitin synthesis in postmolt blue crabs

Chitin synthesis in crustaceans involves the deposition of a protein-polysaccharide complex at the apical surface of epithelial cells which secrete the cuticle or exoskeleton. The present study involves an examination of in vivo incorporation of radiolabeled amino acids and amino sugars into the cuticle of postmolt blue crabs, Callinectes sapidus. Rates of incorporation of both 3H leucine and 3H threonine were linear with respect to time of incubation. Incorporation of 3H threonine into the endocuticle was inhibited greater than 90% in the presence of the protein synthesis inhibitor, puromycin. Linear incorporation of 14C glucosamine into the cuticle was also demonstrated; a significant improvement of radiolabeling was achieved by using 14C-N-acetylglucosamine as the labeled precursor. Incorporation of 3H-N-acetylglucosamine into the cuticle of postmolt blue crabs was inhibited 89% by puromycin, indicating that concurrent protein synthesis is required for the deposition of chitin in the blue crab. Autoradiographic analysis of control vs. puromycin-treated crabs indicates that puromycin totally blocks labeling of the new endocuticle with 3H glucosamine. These results are consistent with the notion that crustacean chitin is synthesized as a protein-polysaccharide complex. Analysis of the postmolt and intermolt blue crab cuticle indicates that the exoskeleton contains about 60% protein and 40% chitin. The predominant amino acids are arginine, glutamic acid, alanine, aspartic acid, and threonine.     

Protein-polysaccharides of pig laryngeal cartilage

1. Protein-polysaccharides of chondroitin 4-sulphate were extracted with neutral calcium chloride from pig laryngeal cartilage that was not completely homogenized. The protein-polysaccharides were purified by precipitation with 9-aminoacridine. On zone electrophoresis in compressed glass fibre at pH7.2 it was separated into two fractions, although two distinct zones were not obtained. These fractions, which had already been shown to differ in their antigenic determinants, also differed considerably in amino acid composition, total protein, hexose and glucosamine contents. 2. The fraction of higher mobility contained approx. 2% of protein and only traces of glucosamine. Serine and glycine accounted for over half the total amino acid residues, but aromatic, basic and sulphur-containing amino acids were not detected. The weight-average molecular weight, determined by sedimentation, was 230000. 3. Assuming that there was the same sequence of neutral sugars at the linkage points as in PP-L fraction (protein-polysaccharide light fraction), the approximate molar ratio of hexose to serine suggested that most of the serine residues were linked to chondroitin sulphate chains. Support for this was derived from the agreement between the weight-average molecular weight of the chondroitin sulphate-peptide after proteolysis, and the chain weight calculated from its serine content. The chain weight based on the serine content of the fraction of higher electrophoretic mobility was approximately similar. 4. In contrast, the fraction of lower electrophoretic mobility resembled PP-L fraction in its amino acid composition, protein and glucosamine contents. The presence of glucosamine, together with the higher hexose content, suggested that this fraction contained some keratan sulphate. 5. The relatively low molecular weight of the fraction of higher mobility enabled it to be extracted without complete disintegration of the cartilage. The unlikelihood of its being produced by autolytic enzymes is discussed.     

Characterization of a glycoprotein in the cyst fluid of Cysticercus tenuicollis from the goat

Dixon S. N., Gibbons R., Parker Janice and Sellwood R. 1973. Characterization of a glycoprotein in the cyst fluid of Cysticercus tenuicollis from the goat. International Journal for Parasitology3:419–424. In the fluids of two tapeworm cysts from goats a prominent periodic acid- Schiff reagent staining protein was found on gel electrophoretograms. In one case serum proteins from the host were also observed. The glycoprotein has been isolated and found to contain about 7·7 per cent heterosaccharide consisting of glucose, galactose, mannose, fucose, neuraminic acid, glucosamine and an unidentified component. The amino acid portion is extremely rich in glutamic acid, aspartic acid, lysine and arginine. Its molecular weight is approximately 90,000. A small degree of heterogeneity was demonstrated by ultra-centrifugal analysis; this may be due to the presence of about 3 per cent of a glycosaminoglycan. In view of the high proportion of charged amino acids it is suggested that this glycoprotein, which appears to be derived from the parasite, functions as the osmotically active macromolecule in the cyst fluid maintaining the turgidity of the cyst.     

Cell wall composition in the ascomycete sphaerostilbe repens at different developmental stages

Changes in the biochemical composition of isolated cell walls were analysed during the differentiation of coremia and rhizomorphs in Sphaerostilbe repens.Differentiation was accompanied by exclusively quantitative variations of the wall components: the content in carbohydrates, chitin and free amino sugars increased; on the contrary, amino acids, uronic acids, lipids and mineral substances decreased.Carbohydrates were composed of glucose, galactose and mannose; glucosamine was the main component of amino sugars. The predominant amino acid in the walls was cysteine the amount of which increased during hyphal aggregation, while quantities of the sixteen other determined amino acids decreased.Mineral matter was present in large quantities in the walls of the fungus, especially in vegetative mycelium. Iron, phosphorus and calcium were the most abundant elements.Possible relations between the variations in chemical composition of the wall and the capability of hyphae to aggregate are discussed.     

Changes in glucosamine and galactosamine levels during conidial germination in Neurospora crassa.

The levels of glucosamine and galactosamine were determined in conidia, germinating conidia, and vegetative mycelia of Neurospora crassa. In the vegetative mycelia about 90% of the amino sugars were shown to be components of the cell wall. The remaining 10% of the amino sugars were tentatively identified as the nucleotide sugars uridine diphospho-2-acetamido-2-deoxy-D-glucose and uridine diphospho-2-acetamido-2-deoxy-D-galactose. Conidia and vegetative mycelia contained about the same levels of glucosamine. During the first 9 h after the initiation of germination, the total glucosamine content had increased 3.1-fold, whereas the residual dry weight of the culture had increased 7.7-fold. This led to a drop in the glucosamine concentration from 100 mumol/g of residual dry weight to 42 mumol/g. During this time, all of the conidia had germinated and the surface area of the new germ tubes had increased to 10 times that of the conidia. Either germ tubes were initially produced without glucosamine-containing polymers, or these polymers (probably chitin) were deposited only at low densities in the germ tube cell walls. The chitin precursor uridine diphospho-2-acetamido-2-deoxy-D-glucose was present at all times during conidial germination. Conida contained very low levels of galactosamine. During germination, galactosamine could not be detected until the culture had reached a cell density of about 0.6 mg of residual dry weight per ml of growth medium. This was observed regardless of the time required to reach this cell density or the fold increase in dry weight. The accumulation of galactosamine-containing polymers does not appear to be necessary for germ tube formation. The levels of soluble galactosamine (uridine diphospho-2-actamido-2-deoxy-D-galatose) were very low in conidia and increased during germination at the same time that galactosamine appeared in the cellular polymers. In addition, under certain culture conditions, the appearance of galactosamine and the increase in the glucosamine concentration occurred simultaneously.     

Agglutinin from Limulus polyphemus. Purification with formalinized horse erythrocytes as the affinity adsorbent.

We have purified an agglutinin from the hemolymph of Limulus polyphemus about 1500-3000-fold by adsorption to formalinized horse erythrocytes, elution with N-acetylneuraminic acid and subsequent fractionation on Sephadex G-200. Recovery was in the range of 50 percent. On ultracentrifugation the agglutinin behaves as an homogenous protein with a molecular weight of about 460 000. On polyacrylamide gel electrophoresis of the dissociated protein in sodium dodecylsulfate we found a single prominent diffuse band with an apparent molecular weight of 22 000 plus or minus 2000. This band contained carbohydrate as determined by periodic acid-Schiff staining. The intensity of staining compared with standards suggested a carbohydrate content of less than 4 percent. The protein contains a preponderance of acidic amino acids and has an isoelectric point of 4.83.5 residues per 1000 of glucosamine were detected on amino acid analysis. Agglutination of formalinized horse erythrocytes by the purified protein is inhibited not only by N-acetylneuraminic acid but also by D-glucuronic acid; but not by a number of other monosaccharides. D-Glucuronic acid may be used in place of N-acetylneuraminic acid as the eluting sugar in the purification procedure.     

Biochemical properties of phosphatidylcholine-binding proteins that share common antigenic determinants with Fc gamma 2b receptor

Biochemical and immunological properties of biosynthetically radiolabeled phosphatidylcholine-(PC-) binding proteins were investigated. The PC-binding proteins were extracted from the detergent lysate of biosynthetically radiolabeled P388D1 cells by affinity chromatography on PC-Sepharose and filtered through a Sephadex G-100 gel column in the presence of 6 M urea. Isoelectric focusing of the gel-filtered materials in the presence of 6 M urea revealed the presence of a major protein component of pIe of 5.8 and minor heterogeneous cellular proteins. The yield of the electrofocused PC-binding proteins based on protein determination by Lowry's method ranged from 0.7 to 4 mg per 10(9) cells. The purified PC-binding proteins appeared to be tightly associated with Triton X-100 and phospholipids in the weight ratio of 0.57 and 0.05 g/g of proteins, respectively. The majority of lipids that could be extracted from the PC-binding proteins by chloroform/methanol (2:1 v/v) are free fatty acids, whereas lipids extracted from Pronase-treated PC-binding proteins contained phosphatidylethanolamine. By amino acid analysis, the purified PC-binding proteins were found to consist of a minimum of 417 amino acid residues, suggesting a minimum molecular weight of about 38 000 for this protein. Results of radiolabeling experiments with [3H]glucosamine and amino acid analysis both showed the presence of a mole of glucosamine per a mole of the PC-binding proteins, suggesting their glycoprotein nature. About 40% of the purified PC-binding proteins coprecipitated with monoclonal anti-Fc gamma 2bR antibody (2.4G2) in detergent-containing buffer, whereas only 6% of the isolated IgG binding proteins reacted with this antibody.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of human angiotensinogen

In this study of the physical and chemical properties of human angiotensinogen were determined. Human angiotensinogen is a glycoprotein containing 14% carbohydrate. The molecular weight as determined by sedimentation equilibrium studies was 56,800. A higher molecular weight was obtained on sodium dodecyl sulfate electrophoresis. Ferguson-type plots indicated that angiotensinogen is another glycoprotein which behaves anomalously on sodium dodecyl sulfate electrophoresis. The COOH-terminal amino acid was found to be serine while two NH2-terminal amino acids, alanine and aspartic acid (or asparagine), were detected. The specific angiotensin I content of angiotensinogen preparations can vary considerably with no effect on the apparent homogeneity of the isolated protein. A protein with negligible angiotensin I content has been obtained from a preparation of human angiotensinogen. The COOH-terminal amino acid of this protein was serine while the only NH2-terminal amino acid detected was alanine.     

Chemical Composition of the Cell Wall of the H37Ra Strain of Mycobacterium tuberculosis

The cell wall of the H37Ra strain of Mycobacterium tuberculosis was isolated and freed of extraneous noncovalently linked material by a series of extraction and enzymatic procedures. Chemical analysis of the cell wall has revealed the following composition: 22.8% amino acids, principally alanine, glutamate, and diaminopimelate in a molar ratio of 1:1.8:0.8; 24.7% reducing sugars, all in the form of arabinose and galactose in a molar ratio of 2.6:1; and 3.95% amino sugars, all in the form of glucosamine, muramic acid, and galactosamine in a molar ratio of 1:6.6:0.8. About 32.1% of the dry weight of the cell wall is lipid, of this about 55% is in the form of two series of mycolic acids. Each series of mycolic acids contains two homologues differing by 28 mass units. One pair of homologues contains in each a carbonyl function and an unsaturated double bond; the other pair contains two cyclopropane groups in each homologue. The remaining lipids are composed principally of normal saturated fatty acids, including tuberculostearic acid.     

Preparation and Chemical Composition of the Cell Walls of Mature Infectious Dense Forms of Meningopneumonitis Organisms

Relatively large-scale production and purification of meningopneumonitis organisms was developed for chemical and immunological studies on cell walls of the infectious dense forms. By disruption of purified organisms with glass beads in a Mickle shaker, highly purified preparations of cell walls were obtained by sucrose density gradient centrifugation, enzyme digestion, and sodium dodecyl sulfate treatment. The dry-weight recovery of purified cell walls from intact organisms was about 13%. When (32)P-labeled preparations of cell walls were fractionated into acid-soluble, lipid, ribonucleic acid (RNA), deoxyribonucleic (DNA), and residual fractions, about 80% of the (32)P in cell wall preparations was recovered in the phospholipid fraction, which corresponded to about 3% of the total phospholipid in the intact organisms. About 7% of the (32)P in purified cell walls was recovered in the RNA and DNA fractions respectively, but this corresponds to only about 0.4% of the (32)P found in those fractions in intact organisms. From dry-weight determinations, it was calculated that the purified cell wall preparations contained only 0.6% total nucleic acids, and these are probably not true cell wall constituents. These cell walls contained 70 to 75% protein, corresponding to about 14% of the protein in intact organisms. Amino acid analysis of these protein showed the existence of all common amino acids, glucosamine, and galactosamine. However, no muramic acid was detected by the methods employed.     

A single-sample method for determination of carbohydrate and protein contents glycoprotein bands separated by sodium dodecyl sulfate- polyacrylamide gel electrophoresis.

A method is described for determination of carbohydrate and protein contents of glycoproteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then electroblotted onto polyvinylidene difluoride (PVDF) membranes. Blots were stained, and appropriate pieces of PVDF membranes were excised, destained, and subjected to sequential hydrolysis with 0.2 M trifluoroacetic acid (TFA) for 1 h at 80 degrees C, then with 2 M TFA for 4 h at 100 degrees C, and finally with 6 M HCl at 100 degrees C for 24 h to release sialic acids, neutral sugars with hexosamines, and amino acids, respectively. In some instances preliminary methanolysis was used. Carbohydrates including sialic acids were quantitated by high pH anion exchange chromatography with pulsed amperometric detection. Protein content of the bands was determined as amino acids by the fluorescamine or ninhydrin method. In the calculation of results proper adjustments were made for small amounts of fucose released by hydrolysis with 0.2 M TFA at 80 degrees C, and for partial degradation of protein during hydrolysis with 2 M TFA at 100 degrees C. Recoveries of amino acids from hydrolysates of glycoproteins that had been electroblotted onto PVDF membranes equaled those of carbohydrates. This was possible because of preliminary hydrolysis of glycoproteins with TFA, as well as washing of wet, instead of dried, PVDF membranes after hydrolysis with 6 M HCl. The two modifications increased yields of amino acids by about 30%. The method was successfully applied to the determination of molar and weight percentage composition of human transferrin, band 3 protein, glycophorin A, and alpha(1)-acid glycoprotein. In each case the results obtained for directly hydrolyzed and electrophoresed/electroblotted glycoproteins were practically identical. We also determined the glucosamine content of band 4.1 protein of erythrocytes.     

The hypobranchial mucin of the whelk Buccinum undatum L. Properties of the mucin and of the glycoprotein component

1. The composition of the hypobranchial mucin from Buccinum undatum is reported. 2. The amino acid composition was determined; aspartic acid and glutamic acid contribute almost 24% of the total amino acids in the mucin. 3. Serine, threonine and alanine, in the proportions 2:1:1 respectively, were detected as N-terminal residues, implying the presence of at least four protein chains. 4. A glycoprotein component was isolated by phenol precipitation. 5. The glycoprotein contained 8% of neutral sugars comprising glucose, galactose, mannose and fucose, and 4.5% of hexosamine, comprising glucosamine and galactosamine in equal proportions. 6. A method is described for the preparation of glycopeptides from the glycoprotein. 7. The comparative biochemistry of the mucin is discussed.     

NUTRITIONAL VALUE OF THE FIELD CRICKET (GRYLLUS TESTACEUS WALKER)

Abstract The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.     

油葫芦的营养价值(英文)

本研究旨在确定油葫芦Gryllus testaceus Walker的主要营养成分和营养价值。研究发现油葫芦体内主要含有蛋白质、脂类和几丁质三类物质,它们的含量(干重比)分别是58.3％,10.3％和8.7％。其中必需氨基酸的含量除了半胱氨酸和蛋氨酸外,非常符合FAO／WHO所确定的人体对氨基酸需求标准。脂肪酸分析显示,不饱和脂肪酸的含量很高,仅油酸、亚油酸和亚麻酸的含量就占总脂肪含量的77.51％。油葫芦的甲壳素含量为8.7％,而且从该虫提取甲壳素／壳聚糖的品质在甲壳素色泽及残留灰分含量、壳聚糖粘度等方面比常规甲壳素原料虾蟹壳的好。因此,油葫芦可以作为很好的食品或饲料添加剂,或医药原料。     

Characterization of pig pancreatic kallikreins A and B.

Pig pancreatic kallikreins A and B are both composed of the same 229 amino acids, a figure resembling the number of amino acid residues found in other serine proteinases of pancreas. Both forms of the enzyme contain N-terminal isoleucine and alanine and C-terminal leucine/serine (about half a mol each per mol kallikrein) and proline. Values for the glucosamine content of the kallikreins obtained on the amino acid analyzer after hydrolysis with p-toluenesulfonic acid, a procedure also used for the determination of amide ammonia, agreed with those determined by a gas-chromatographic method. Neuraminidasetreated kallikrein B differs from the A form only in containing roughly double the amount (on the average a total of 11.5 vs. 5.6% by weight) of carbohydrate (glucosamine, mannose, galactose, and fucose) and possibly by a higher content (20 vs. 17 residues) of amide ammonia. From the composition, molecular weights of 26800 and 28600 are calculated for sialic-acid-free kallikreins A and B, respectively, and of 25300 for the protein part of kallikrein. The molar absorbance of both forms of the enzyme has been determined as (50.6 +/- 1.3) X 10(3)M-1 cm-1 at 280 nm. A comparison of kallikreins A and B with kallikreins d1 and d2 described by Zuber and Sache reveals as principal difference a much lower specific activity of the latter preparations with all reagents tested. Conceivably, the reported lower carbohydrate contents of kallikreins d1 and d2 and their separation into three instead of two major subunits are related to this finding.     

皱肋文蛤氨基酸含量及脂肪酸组成分析

测定了皱肋文蛤(Meretrix lyrata)软体部分的氨基酸含量与脂肪酸组成.共检出17种氨基酸,总含量为软体部干重的52.26%;4种呈味氨基酸(天门冬氨酸、谷氨酸、甘氨酸和丙氨酸)的含量为22.07%,占氨基酸总量的42.23%;必需氨基酸(EAA)总含量为20.72%,其必需氨基酸的构成比例基本符合FAO/W...