Isao Kiyosawa

Studies on human casein: I. Fractionation of human casein by diethylaminoethyl cellulose column chromatography

Abstract Fractionation of human casein by diethylaminoethyl (DEAE) cellulose column chromatography has been performed by gradient sodium chloride elution (0 ~ 0.21 m ) and stepwise elution (0.02 m sodium phosphate buffer containing 1.0 m sodium chloride and 0.2 n sodium hydroxide) at 10 ° without addition of urea; acrylamide gel electrophoresis in the presence of urea (AGUE) was used to determine homogeneity. Human casein was separated into at least nine fractions (F-1 through F-9), all of which were heterogeneous. Whole casein showed 14 ~ 26 bands on AGUE, which were designated as ρ-, α-, β-, and γ- μ caseins according to their (decreasing) mobilities. The main component of human casein was the (β-casein group (F-1 through F-6). No calcium-sensitive fraction corresponding to cow α s -casein could be found in human casein, whereas F-7, containing 0.97% phosphorus and 1.63% sialic acid, seemed to be a characteristic fraction of human casein.

THE CONTENT OF FREE AND BOUND INOSITOL IN HUMAN AND COW'S MILK

The gaschromatographic method was used for the quantitative analyses of inositol in milk. The content of inositol in human and cows milk at the different lactation periods was determined. The content of total myoinositol in human milk was 32.7 plus or minus 15.2 mg/100 ml in colostrum, 17.8 plus or minus 1.9 mg/100 ml in transitional milk, and 14.9 plus or minus 3.1 mg/100 ml in mature milk. In cows milk, it was 10.6 plus or minus 1.0, 7.0 plus or minus 1.1, and 4.1 plus or minus 1.0 mg/100 ml, respectively. These values were very similar to those obtained by the microbiological method. The presence of lipid-bound myoinositol in both kinds of milk was confirmed and the content was 0.22 plus or minus 0.09 mg/100 ml in human milk and 0.36 plus or minus 0.10 mg/100 ml in cows milk. A small amount of scylloinositol was found in both human and cows milk, while dextroinositol was not found in either.

Suppressive Effects of Lactoferrin on Bleomycin-dependent DNA Damage by the Iron Ion and Ascorbate

The effects of the iron ion and reductones on bleomycin (BLM)-induced DNA degradation were observed by measuring the amount of malondialdehyde (MDA) formed. The formation of MDA was detected after adding Fe(2+) or Fe(3+) + Asc combined to a solution consisting of DNA and BLM, but not after adding Fe(3+) alone, catecholamines or phenolic compounds. Marked suppressive effects of lactoferrin (Lf) and ovotransferrin on MDA formation were observed in the solution with Fe(2+) or Asc. However, serum albumin, β-lactoglobulin, α-lactalbumin, and ovoalbumin had no effect on suppressing MDA formation. The suppression by bovine Lf (bLf) of MDA formation decreased with increasing iron saturation at 1.0 mm Fe(2+), but at 100% iron saturation, 51.2% of apo-bLf remained suppression. In the solution with 0.25 mm Asc, 100% iron saturated bLf markedly enhanced MDA formation.

Changes in the Chemical and Functional Properties in Mozzarella Cheeses Made by Different Salting Methods during Aging

牛乳にスターターおよびレンネットを添加して得たカードに,2%食塩を添加し,モザレラチーズ(DMC)を調製し,4°C,60日間貯蔵した.また,カードを23%食塩水に浸漬してモザレラチーズ(BMC)を調製し,同じ条件で貯蔵した.DMCチーズ(チーズ外側試料)100g当たりの非タンパク態窒素および水溶性カルシウム含量は,貯蔵1日目でそれぞれ19および245mgであったが,60日目ではそれぞれ90および360mgに増加した.一方,水溶性リン含量は,1日目で140mgであったが,60日目で113mgに減少した.これらの変化は,BMCチーズ(チーズ外側試料)でも観察された.DMCおよびBMCにおけるカゼインの尿素-PAGEでは,αs1-カゼインのバンド強度は著しく減少したが,いずれのチーズもβ-カゼインではわずかな減少に過ぎなかった.チーズの糸引き性は,貯蔵1日目では低かったが,15日目以降に高まった.4°C貯蔵中のDMCとBMCの間の化学的性質および機能性には,顕著な差異が認められなかった.

Effect of myo-inositol on the growth of young rat.

生後, 約20日を経過したS. D. 系幼若ラットを1群7匹とし, イノシット無投与群 (G-1), 0.5mg/日 (G-2), 1.0mg/日 (G-3) および2.0mg/日 (G-4) 投与群の4群に分けて, 体重増加ならびに臓器の重量, イノシット含量および酵素活性を測定した。 その結果は次の通りであった。(1) 54日間飼育後の各群の1日当りの平均体重増加量および飼料効率は次の通りであった。 G-1: 0.43g, 0.383. G-2: 0.88g, 0.638. G-3: 1.33g, 0.989. G-4: 1.15g0.769.(2) 各ラット群間の肝臓, 腎臓, 心臓, 眼球重量には顕著な差は認められなかったが, G-1とG-4は他の2群に比較して睾丸重量が低かった。(3) 各ラット群間の血清1ml中の蛋白質量および非蛋白態窒素量は次の通りであった。G-1: 62.05mg, 0.66mg. G-2: 65.58mg, 0.53mg. G-3: 69.94mg, 0.56mg. G-4: 70.55mg, 0.51mg.(4) 各ラット群間の血清100mg中の全脂質, コレステロール, リン脂質量は次の通りであった。 G-1: 700.0mg, 49.6mg, 120.5mg. G-2: 649.0mg, 43.4mg, 125.0mg. G-3: 589.2mg, 35.1mg, 136.5mg. G-4: 588.0mg, 39.4mg, 141.0mg.(5) イノシット生合成に関与するグルコース-6-リン酸シクラーゼとイノシット-1-リン酸ボスファターゼ活性は, 肝臓, 腎臓, 睾丸において各ラット群の間に有意差は認められなかったが, その平均値は無投与群より投与群においてその活性が高い傾向が観察された。(6) 心臓, 肝臓のイノシット含量は各ラット群の間に殆んど差がなかった。 しかし無投与群の眼球のイノシット含量は他の投与群に比較して低かった。

Studies on the Proteins of Human Milk:Part VIII. Isolation and Characterization of Human Milk β 2 A-Globulin

Milk β2A-globulin was isolated by rechromatography of the globulin fraction of human milk on DEAE-cellulose column. Milk β2A-globulin containinig 12.1% of carbohydrates was homogeneous in the electrophoresis and ultracentrifuge. Physicochemical properties of human milk β2A-globulin were studied.