PURIFICATION AND PARTIAL CHARACTERIZATION OF TWO α-AMYLASE INHIBITORS FROM BLACK BEAN (Phaseolus vulgaris)1

Two α-amylase inhibitors from black bean (Phaseolus vulgaris) were purified to homogencity using ammonium sulfate fractionation, DEAE-Sephadex chromatography, phenyl-Sepharose hydrophobic interaction chromatography and gel filtration with Sephadex G-100. The inhibitors were designated I–1 and I–2 based on their order of elution from the phenyl-Sepharose column. Both inhibitors are mannose containing glycoproteins, composed of subunits; active against porcine pancreatic, human salivary, and insect α-amylases and inactive against bacterial, mold, and plant α-amylases. The inhibitors I-1 and I–2 have molecular weights of 49,000 and 47,000 and isoelectric points 4.93 and 4.86, respectively. Both inhibitors have similar amino acid compositions and are rich in aspartic acid, serine, glutamic acid, valine, and threonine and are low in sulfur containing amino acids. I–2 is more resistant to heat denaturation than I-1.     

PURIFICATION AND PARTIAL CHARACTERIZATION OF WHITE KIDNEY BEAN (PHASEOLUS VULGARIS)β-AMYLASE INHIBITORS FROM TWO EXPERIMENTAL CULTIVARS

β-Amylase inhibitors WKB 858B and WKB 858B were purified to homogeneity from different cultivars of white kidney beans by extraction from the ground beans and by sequential heat treatment, ethanol fractionation, DEAE-cellulose chromatography, Sephadex G-75 gel chromatography and CM-cellulose chromatography. The inhibitors were homogeneous by 7.5% polyacrylamide gel electrophoresis; no isoinhibitors were found. Inhibitors WKB 858A and WKB 858B had isoelectric points of 5.0 and 4.65, respectively, and molecular weights of 42,000 and 20,000, respectively, by FPLC Superose 12 gel filtration chromatography. Inhibitor WKB 858A had molecular weights of 40,000 and 38,000 by Sephadex G-75 gel filtration chromatography and by native gel electrophoresis, respectively. Inhibitor WKB 858A contained 11.0% carbohydrate, N-linked to asparagine residues, with a composition of 1 fucose, 1 xylose, 4 galactose, 8 N-acetylglycosamine and 13 mannose residues per mol of inhibitor. Amino acid analysis of Inhibitor WKB 858A gave a high content of Asx, Glx, Ser, Thr and Val (combined total of 60% molar ratio) and low content of sulfur amino acids (0.8% molar ratio of Met and no 1/2 cystine). No-SH groups were found. The amino acid composition was similar to that of eight other a-amylase inhibitors from beans. Inhibitor WKB 858A formed a 1:1 stoichiometric complex with porcine pancreatic a-amylase with a Ki of 1.0 × 10^?11 M at pH 5.4 and 30C; it had no trypsin inhibitory activity. At pH 6.90 and 30C, the rate of complex formation between Inhibitor WKB 858A and porcine pancreatic β-amylase was 2.76 times faster at 1.385 vs 0.035 ionic strength (with Na₂SO₄), indicating hydrophobic bonds are most important in complex formation.     

Natural plant enzyme inhibitors. α-amylase inhibitors in millets

Twelve varieties of sorghum (Sorghum bicolor), 14 varieties of pearl millet (Pennisetum typhoideum), 12 varieties of setaria (Setaria italica), four varieties of ragi (Eleucine coracana), 11 varieties of echinocloa millet (Echinocloa colona), 13 varieties of proso (Panicium miliaceum), 11 varieties of kodo (Paspalum scorbiculatum) and 11 varieties of miliare (Panicium miliare) were screened for inhibitory activity against human salivary amylase. Echinocloa, proso, kodo and miliare had no detectable activity. Two strains of sorghum and one strain of pearl millet did not show α-amylase inhibitory activity. All other seeds had activity, the highest being observed in sorghum. Setaria had no action on human, bovine and porcine pancreatic anylases. Sorghum inhibitor did not act on bovine and porcine pancreatic amylases. Pearl millet and ragi extracts inhibited all the four α-amylases. The inhibitors were non-dialysable and were inactivated by pepsin treatment. Setaria and sorghum inhibitors were relatively thermolabile compared to ragi and pearl millet inhibitors.     

Natural plant enzyme inhibitors. Studies on a proteinase inhibitor from Italian millet (Setaria italica)

A proteinase inhibitor specific for trypsin was purified from Italian millet (Setaria italica) 170-fold by extraction with 0.02M HC1, ammonium sulphate fractionation, chromatography on CM-cellulose and trypsin-affigel chromatography. The inhibitor with an M_r of 14000 was found to be homogeneous by gel chromatography on Sephadex G-100 and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. It reacted with bovine trypsin in a 1:1 stoichiometric fashion. Inhibition of trypsin was nearly double when assayed with benzoyl DL -arginine p-nitroanilide as substrate compared to the activity with casein as substrate. The inhibitor affected the tryptic activity in human and bovine pancreatic preparations to an equal extent. Chemical modification studies showed that amino groups, disulphide bridges and sulphydryl groups are essential for the action of the inhibitor. Pretreatment with porcine pepsin or bovine α-chymotrypsin increased the antitryptic activity of the inhibitor when assayed with the low molecular weight substrate but not with casein.     

Natural plant enzyme inhibitors. Purification and properties of an amylase inhibitor from yam (Dioscorea alata)

A high-molecular-weight α-amylase inhibitor has been isolated from mature tubers of Dioscorea alata by extraction with 0.02M acetate buffer (pH 5.0), negative absorption on CM-cellulose and ultracentrifuging. The inhibitor was fairly heat stable and was active against human salivary, human pancreatic and pig pancreatic amylases. The inhibitor had no action on Bacillus subtilis and Aspergillus oryzae amylases. Trypsin and α-chymotrypsin inactivated the inhibitor. Pre-incubation of the inhibitor with starch or concanavalin A resulted in complete abolition of its activity. Chemical modification of the amino groups with trinitrobenzene sulphonic acid led to loss of activity. The inhibitor was found to be a glycoprotein with 64% carbohydrate. The monosaccharide units present were glucose, mannose and galactose in a molar ratio of 5.5:3.8:1.     

Natural plant enzyme inhibitors. Isolation and characterisation of a trypsin/chymotrypsin inhibitor from indian red wood (Adenanthera pavonia) seeds

A trypsin/chymotrypsin inhibitor was isolated from Indian red wood seeds by extraction with 0.01m HCl, chromatography on diethyl amino ethyl-cellulose, ammonium sulphate fractionation and gel chromatography on Sephadex G-100. The homogeneity of the final product was ascertained by affinity chromatography on trypsin sepharose and chromatography on phenyl sepharose CL-4B columns. During all stages of purification and characterisation the ratio of activities against trypsin and chymotrypsin remained constant at about 1.1:1 indicating that the same factor is responsible for both activities. The size of the inhibitor was found to be 24 000 daltons based on gel chromatographic studies on Sephadex G-100 and by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The molar ratio of interaction between the inhibitor and bovine trypsin for complete inactivation of the enzyme was found to be 1.04:1. Electrophoretic and gel chromatographic studies indicated that the purified inhibitor is capable of undergoing aggregation to form dimers and trimers. Even in the presence of sodium dodecyl sulphate and sodium dodecyl sulphateurea, this phenomenon was discernible. The binding sites on the inhibitor for trypsin and chymotrypsin were not mutually exclusive, based on the data from mixed enzyme studies and on analysis of the inhibitor-enzyme complexes by gel chromatography on Sephadex G-100. Modification of the arginyl residues of the inhibitor resulted in the loss of more of the antitryptic activity than of antichymotryptic activity. Conversely, modification of amino groups resulted in the loss of more of the antichymotryptic activity. The inhibitor was stable to exposure to a wide range of pH (1.0–12.0), but it was completely inactivated on heat-treatment at 100°C for 15 min. The mode of inhibition of trypsin as well as chymotrypsin was non-competitive and K_i values for the inhibitor were 2.92 × 10-¹⁰M and 4.46 × 10-¹⁰M , respectively, for the two enzymes.     

PURIFICATION AND CHARACTERIZATION OF α-AMYLASE INHIBITORS IN WHEAT (TRITICUM AESTIVUM VAR. ANZA)

Three α-amylase inhibitors were purified to homogeneity from Anza wheat (Triticum aestivum var. Anza) by extraction with 70% ethanol, ammonium sulfate fractionation and column chromatography on DEAE-cellulose, CM-ceillulose and Sephadex G-50. Homogeneity was determined by disc gel and isoelectric focusing electrophoresis and by sedimentation equilibrium centrifugation. The inhibitors are designated 0.19, 0.28 and 0.55 on basis of their relative electrophoretic mobilities on polyacrylamide gels. The 0.19, 0.28 and 0.55 inhibitors had molecular weights of 24,000, 18,500 and 30,000 by polyacrylamide gel electrophoresis with different gel concentrations while the former two were 29,000 and 14,500 by sedimentation equilibrium centrifugation, respectively. The molecular weight of the 0.55 inhibitor was not determined by centrifugation. The isoelectric points were 5.9, 5.2 and 4.2 for the 0.19, 0.28 and 0.55 inhibitors, respectively. The three inhibitors had similar amino acid compositions but differed significantly in amounts of lysine, arginine, histidine, alanine, valine and phenylalanine. The 0.19 inhibitor was active against human salivary and hog pancreatic α-amylases but inactive against Bacillus subtilis and Aspergillus oryzae α-amylases. The 0.28 inhibitor had very weak activity against only human salivary α-amylase. The 0.55 inhibitor had activity against only human salivary α-amylase. The 0.55 inhibitor appears to differ from all previously reported wheat α-amylase inhibitors while the 0.28 inhibitor (protein) is unique in having essentially no inhibitory activity.     

α‐Amylase inhibitors from an Indonesian medicinal herb,Phyllanthus urinaria

BACKGROUND: Diabetes mellitus and associated diseases are an increasing problem around the world. One of the hyperglycemic remedies is glucose absorption reduction by suppressing carbohydrate digestion due to utilization of α‐amylase inhibitors. RESULTS: Prospective herbs were analyzed by in vitro enzyme assay to evaluate their inhibitory activity against porcine pancreatic amylase (PPA), and it was found that Phyllanthus urinaria and three other herbs to showed a potent inhibitory activity. A 50% aqueous methanol‐soluble extract of the leaves of P. urinaria was chromatographed using a silica gel column. The active fractions were further purified by preparative high‐performance liquid chromatography to isolate active principles against PPA. Structural determination revealed that these isolated compounds were gallic acid, corilagin, and macatannin B, and showed mild activity against PPA (activity in 1 mmol L^?1 concentration: 23%, 21%, 33%, respectively). CONCLUSION: P. urinaria extracts show inhibitory activity against PPA. This activity, together with the information on isolated compounds, may benefit further exploration of P. urinaria utilization in the management of borderline diabetes patients. Copyright © 2011 Society of Chemical Industry     

Thermostable basic proteinase inhibitors from potatoes. Isolation and characterization (author's transl)]

Four basic proteinase inhibitors were isolated from potato tubers (var. Maritta) by ammonium sulfate precipitation, heat treatment, chromatography on CM-cellulose and preparative polyacrylamide gel electrophoresis. Their isoelectric points are in the pH range 9.2--9.8. The molecular weights, as estimated by Sephadex gel filtration, were 8500 for inhibitor K 1 and 22000 for the inhibitors K3, K4, and K6. Differences in inhibitors regarding amino acid composition and specific activity against six different proteinases are discussed. Comparisons with previously described inhibitors are given. A correlation between high cystine content and thermostability of the inhibitor proteins is indicated.     

Multiplicity of Glucoamylase of Aspergillus oryzae Part 1. Separation and Purification of Three Forms of Glucoamylase

The glucoamylase system of Aspergillus oryzae cultured on wheat bran was separated into 3 active fractions by (NH₄)₂SO₄, rivanol and ethanol precipitation followed by ion exchange chromatography on DEAE-Sephadex A-25. One of these fractions, referred to as glucoamylase I was purified by further chromatography on hydroxyapatite gel and Sephadex G-200. The other two fractions referred to as glucoamylase II and III were purified by further gel filtration on Sephadex G-200. The purified glucoamylases were found to be homogeneous on 7.5% polyacrylamide gel electrophoresis and isoelectric focusing by carrier ampholites.     

PURIFICATION AND SOME PHYSICAL AND CHEMICAL PROPERTIES OF RED KIDNEY BEAN (PHASEOLUS VULGARIS) α-AMYLASE INHIBITOR

Red kidney bean contains more amylase inhibitor than do California white bean and cowpea while garbanzo bean and Westan and Westley lima beans do not contain inhibitor. Red kidney bean amylase inhibitor was purified to homogeneity by selective heat treatment (60°C) of a water extract at pH 4. 0, fractionation with ethanol and successive chromatography on DEAE- and CM-cellulose chromatography. The inhibitor has an apparent molecular weight of 49,000 by Sephadex gel filtration and contains 8. 6% carbohydrate probably covalently linked via an amide linkage to asparagine. The inhibitor probably contains four subunits perhaps of three different types. The inhibitor is high in aspartic acid, glutamic acid, serine, threonine and valine, low in cysteine/cystine and does not contain proline. Stable 1:1 complex formation between inhibitor and porcine pancreatic α-amylase was demonstrated by gel filtration on Sephadex G-100. The inhibitor has activity against porcine pancreatic α-amylase, human salivary α-amylase, and Tenebrio molitor (yellow corn meal worm) larval midgut α-amylase but is inactive against Bacillus subtilis α-amylase, Aspergillus oryzae α-amylase, barley α-amylase and red kidney bean α-amylase.     

Purification of trypsin/chymotrypsin inhibitor from jack fruit seeds

A trypsin/chymotrypsin inhibitor (JSTI) was isolated from jack fruit seeds (Artocarpus integrifolia Hook f) by ammonium sulphate fractionation and chromatography on DEAE–cellulose and Sephadex G-100. During all stages of purification, the ratio of trypsin and chymotrypsin inhibitory activities remained constant. The purified preparation was found to be homogeneous by gel filtration, polyacrylamide gel electrophoresis (PAGE) and ultra-centrifugation. From the sedimentation coefficient, S _20w value of 3·5 ± 0·15 S. the molecular weight of JSTI was calculated to be 30·00 ± 2·50 kamu. The inhibitor showed a molecular weight of 24·55 kamu on a Sephadex G-75 column when eluted with 6 M guanidine hydrochloride, Under non-denaturing conditions, JSTI exhibited anomalous behaviour on a Sephadex G-200 column. On SDS–PAGE, the inhibitor showed two major bands with molecular weights of 26·30 and 15·00 kamu and two minor bands with molecular weights of 19·50 and 12·00 kamu. The carboxyamidomethylated JSTI showed three trypsin inhibitory activity bands on PAGE, suggesting the presence of isoinhibitors.     

Angiotensin I-converting enzyme inhibitory peptides in douchi,a Chinese traditional fermented soybean product

Douchi, a soybean product originating in China, produces angiotensin I-converting enzyme (ACE) inhibitors with the potential to lower blood pressure. The ACE inhibitory activities of douchi qu pure-cultured by Aspergillus Egyptiacus for 48 h, and 72 h were compared with douchi secondary-fermented for 15 d. The results showed that ACE inhibitory activities were improved following the fermentation. ACE inhibitory activities of 48 h-primary-fermented douchi qu did not change dramatically after preincubation with ACE, but increased greatly after preincubation with gastrointestinal proteases. The results suggest they were pro-drug-type or a mixture of pro-drug-type and inhibitor-type inhibitors. The ACE inhibitors in 48 h-fermented douchi qu were fractionated into four major peaks by gel filtration chromatography on Sephadex G-25. Peak 2, which had the highest activity, had only one peptide, composed of phenylalanine, isoleucine and glycine with a ratio of 1:2:5.     

榛仁降脂活性肽分离纯化及结构鉴定

采用超滤、Sephadex G-25、Sephadex G-15、反相高效液相色谱及质谱对榛仁分离蛋白降脂活性肽进行分离纯化及结构鉴定,并通过测定3T3-L1前脂肪细胞诱导分化过程中脂质积累、总胆固醇及甘油三酯水平,筛选出具有较高降脂活性的肽段。结果表明,经Sephadex G-15分离得到的C3组分的胰脂肪酶抑制、胆固醇胶束吸附及细胞降脂活性均显著高于其他组分。进一步经质谱解析筛选出的肽段Phe-Leu-Leu-Pro-His（FLLPH）与模型组相比,可抑制26.31%的总脂形成,降低32.67%胆固醇和23.87%甘油三酯水平。FLLPH具有较好的降脂活性,本研究可为榛仁降脂活性肽的开发提供理论参考。     

Purification of a lipase from the hepatopancreas of oil sardine (Sardinella longiceps linnaeus) and its characteristics and properties

Lipase has been purified from the hepatopancreas of oil sardine (Sardinella longiceps) by defatting, water extraction, ammonium sulphate fractionation and chromatography on DEAE Sephadex and Sephadex G-100. The preparation was homogeneous on polyacrylamide disc gel electrophoresis and on gel filtration through Sephacryl S-200. The enzyme showed a molecular weight of 54000±57000 with 6.1% of carbohydrate. The pH and temperature optima of purified sardine lipase were 8 and 37°C respectively. Sardine lipase remained stable up to 45°C (15 min) and in the pH range 5 to 9.5. The K_m values obtained for the substrates tributyrin and triacetin were 4 × 10^?2 and 30 × 10^?2, respectively. The effect of halogens and various metal ions on sardine lipase activity, substrate specificity, amino acid and carbohydrate composition are also reported.     

Isolation and Some Properties of Amylase from Streptomyces hygroscopicus SF-1084

After screening about three thousands of Streptomyces strains from soils, a strain of Streptomyces hygroscopicus SF-1084, which gave the highest amylase production was isolated and some properties of the amylase were studied. Amylase production media were examined and a medium which consisted of glucose 2%, corn starch 5.5%, corn meal 1%, wheat germ 0.5%, soy bean meal 1.4%, KH₂PO₄ 0.2% adjusted to pH 7.0 was used to produce the amylase. Amylase production by 30 l jar fermenter was reached at 1500 u/ml in 110 h culture. The amylase was purified from broth filtrate by the method of ammonium sulfate precipitation, DEAE-sephadex A-50 column chromatography and Sephadex G-150 gelfiltration to get single band on a polyacrylamide disc gel electrophoresis. It is shown that the SF-1084 amylase produced 88% maltose from amylose and 80% maltose from amylopectin in 48 h saccharification. From the pattern of blue value and reducing value, the amylase is supposed to have endogenous action on starch and the activity is not inhibited by PCNB (pentachloronitrobenzene); the SF-1084 amylase does not belong to β-amylase. The optimum pH of the amylase was 5 to 6 and the optimum temperature was 50 to 55 °C. The amylase was fairly thermostable and the residual activity after incubation at 90 °C for 15 min and 100 °C for 15 min were revealed more than 50% and 30% respectively.     

Thermostabile, basische Proteinaseinhibitoren aus Kartoffeln isolierung und charakterisierung

Zusammenfassung Aus Kartoffeln (SorteMaritta) wurden durch Ammoniumsulfatf?llung, Hitzebehandlung, Ionenaustauscherchromatographie und pr?parative Polycrylamidgel-Elektrophorese vier basische Proteinaseninhibitoren isoliert. Die isoelektrischen Punkte der Inhibitoren liegen zwischen pH 9,2 und 9,8. über Sephadex Gelfiltration wurden für den Inhibitor K 1 ein MG von 8500 und für die Inhibitoren K 3, K 4 und K6 ein MG von 22000 bestimmt. Unterschiede bei den Inhibitoren in der AS-Zusammensetzung und in den spezifischen Aktivit?ten gegenüber sechs verschiedenen Proteinasen werden diskutiert. Vergleiche mit früher beschriebenen Inhibitoren werden vorgenommen. Eine Korrelation zwischen hohem Cystin-Gehalt und Thermostabilit?t bei den Inhibitorproteinen wird aufgezeigt.

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Thermostable basic proteinase inhibitors from potatoes isolation and characterization

Summary Four basic proteinase inhibitors were isolated from potato tubers (var.Maritta) by ammonium sulfate precipitation, heat treatment, chromatography on CM-cellulose and preparative polyacrylamide gel electrophoresis. Their isoelectric points are in the pH range 9.2–9.8. The molecular weights, as estimated by Sephadex gel filtration, were 8500 for inhibitor K 1 and 22 000 for the inhibitors K3, K4, and K6. Differences in inhibitors regarding amino acid composition and specificic activity against six different proteinases are discussed. Comparisons with previously described inhibitors are given. A correlation between high cystine content and thermostability of the inhibitor proteins is indicated.

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Wir danken Frau Christine Kmita-Dürrmann für technische Assistenz. Prof. Dr. H.-D. Belitz danken wir für die Unterstützung unserer Arbeit, u. a. durch Mittel der Deutschen Forschungsgemeinschaft (DFG)     

脱脂羊脑蛋白水解多肽的分离纯化及抗氧化活性

为制备羊脑蛋白抗氧化肽,本实验对脱脂羊脑蛋白含量及氨基酸组成进行了分析;采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE）对枯草芽孢杆菌中性蛋白酶不同酶解时间的酶解液分子质量进行了分析;采用交联葡聚糖凝胶Sephadex G-25和Sephadex G-15对羊脑酶解产物进行了逐级分离纯化,以羟自由基（·OH）和亚硝酸根离子清除能力为指标对分离组分进行抗氧活性评价,并对纯化后的组分抗氧化活性进行了测定。结果表明,脱脂羊脑粉中蛋白含量为60.55%,在测定的17 种氨基酸中,谷氨酸和天冬氨酸这两种酸性氨基酸含量最高,且含有7 种必需氨基酸;羊脑蛋白经酶解后,分子质量集中在10 kD以下;经Sephadex G-25纯化后,得到了6 个组分,其中组分F4的抗氧化活性最强,组分F4经SephadexG-15纯化后,得到3 个组分,其中组分F4-2的抗氧化活性最强,组分F4-2对1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、·OH、超氧阴离子自由基（O2－·）、亚硝酸根离子的半数抑制率IC50分别为1.64、2.47、7.98、5.14 mg/mL。     

Some Enzyme Properties of Raw Starch Digesting Amylases from Streptomyces sp. No. 4

Streptomyces sp. No. 4 produce two forms of amylase that attack raw cassava starch. Both forms, amylase‐1 and amylase‐2, were purified by starch adsorption, affinity chromatography, and ion exchange chromatography. The molecular weights of amylase‐1 and amylase‐2 as determined by SDS‐PAGE were 56 kD and 77 kD, respectively. Optimal enzyme activities occurred at pH 5.5 and at 50°C for amylase‐1 and at 45°C for amylase‐2. The activation energy of amylase‐1 and amylase‐2 were 67 and 42 kJ/mol, respectively. Hg²⁺ and pCMB inhibited both enzymes, whereas 2‐mercaptoethanol activated only amylase‐2. EDTA inhibited amylase‐1 but activated amylase‐2. The main product of hydrolysis of raw cassava starch by amylase‐1 was maltose, followed by maltotriose, maltotetraose and dextrin. Amylase‐2 cleaved raw cassava starch to produce glucose and maltose as main products. Both amylase‐1 and amylase‐2 are α‐amylases, as shown by the fast disappearance of iodine staining, the corresponding reaction products and the ability of both enzymes to hydrolyze crosslinked blue starch.     

ISOLATION AND GENERAL PROPERTIES OF LECTINS FROM THE BEAN (PHASEOLUS VALGARIS VAR. ROSINHA G2)

A purified lectin was prepared from 0.15 M NaCl extracts of bean (Phaseolus vulgaris var. Rosinha G2) by affinity chromatography on ConA-Sepharose followed by gel chromatography on Sephadex G-200. The haemagglutining material isolated by affinity chromatography (CII-Af) contained at least three active protein bands as shown by polyacrylamide gel electrophoresis. By chromatography on a Sephadex G-200 column, the (CII-Af) fraction gave only a major peak (CII-β) with haemagglutininating activity, which showed a single broad band on gel electrophoresis. Gel isoelectric focusing of the CII-β component gave a single active band in the pH range of 5.5–5.7. The purified lectin was a glycoprotein, containing 8.30% of neutral sugars (as mannose) and 2.12% of hexosamine (as glucosamine) and only trace amounts of sulphur-containing amino acids. The protein had a MW of 136,000 (6.9 S) with a Stokes radius of 43 Å, a calculated diffusion constant (D_20,w) of 5 times 10^?7 cm² s^?1, and a partial specific volume (v) of 0.75 ml.g^?1. From its frictional ratio f/fo = 1.3 and assuming a hydration capacity of 0.3 to 0.4 g of water/g of protein, the axial ratio for the lectin molecule would be in the range of 3–4 if a prolate ellipsoid of revolution is chosen as a model.