Characterization of Collagen Enzymatic Hydrolysates Derived from Lizardfish (Synodus fuscus) Scales

Acid soluble collagen was extracted from the scales of lizardfish and characterized with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis. After 8 h of collagen hydrolysis, hydrolysates had an estimated degree of hydrolysis (DH) from 4 ± 0.05 to 25 ± 0.63% (p < 0.05). All hydrolysates had angiotensin converting enzyme inhibitory and antioxidant activity. These activity levels showed little change after treatment with gastrointestinal proteases. Results indicated that the lizardfish by-products may be improved by enzymatic treatment with acid-soluble collagen from lizardfish scales.     

Wound healing potential of Tragia involucrata extract in rats

The methanol extract of the roots of Tragia involucrata topically tested at doses of 100 and 200 mg/kg exerted significant wound healing effect in Staphylococcus aureus-induced excision wound in rats.     

Characteristics of Collagen from Rohu (Labeo rohita) Skin

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were isolated from rohu skin with the yield of 64.2 and 6.8% (dry weight basis), respectively. Both collagens had glycine as the major amino acid with imino acid content of 196–202 residues/1,000 residues and were characterized as type I collagen with molecular composition of (α1)₂α2-heterotrimer. Fourier transform infrared spectra of both collagens were similar, with no shift in wavenumber of all amide bands. The T_max value of ASC and PSC was 36.40 and 35.48°C, respectively. The zero surface net charge of ASC and PSC was found at pH 5.9 and 5.3, respectively.     

Preparation and Characterization of Protein Hydrolysates From Little Loligo Squid (Uroteuthis chinensis)

Research on the little loligo squid (Uroteuthis chinensis) protein hydrolyzed by papain and Flavourzyme and characterization of hydrolysates was carried out in this article. The optimum hydrolysis conditions of papain were obtained by orthogonal experiments, and the influence factors on the degree of hydrolysis such as enzyme/substrate ratio, hydrolysis time, pH, and temperature were investigated. The effect of Flavourzyme on the degree of hydrolysis was also studied. The characteristics of freeze-dried hydrolysates such as yield, moisture, nitrogen recovery, molecular mass distribution, and amino acid composition were determined. The results showed that papain and Flavourzyme could hydrolyze the little loligo squid protein efficiently, and the degree of hydrolysis was up to 25.82% under the optimum hydrolysis conditions. The average molecular mass of hydrolysates obtained with papain and Flavourzyme was 1,246 Da, and the low molecular mass peptides were the main fraction of hydrolysates. The yield, moisture, and nitrogen recovery of freeze-dried hydrolysates was 19.8, 4.4, and 74.2%, respectively. Compared with suggested patterns of amino acid requirements by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO), the hydrolysates of the little loligo squid had high nutritional value, and was a potential nutritious supplement used in various food products.     

白酒糟水解液摇瓶发酵生产木糖醇的工艺优化

为充分利用白酒糟资源,探讨酸水解液作为碳源发酵生产木糖醇的可行性。采用热带假丝酵母(Candidatropicalis1779)发酵酒糟水解液生产木糖醇,分别利用单因素试验和正交试验考察了影响发酵的工艺条件。发酵在250mL摇瓶发酵瓶中进行。结果表明,当种子龄27h、接种量20mL、装液量100mL、氮源添加量20mL、氮源浓度48g/L时发酵效果最好。该条件下发酵液中木糖醇浓度为11.85mg/mL,木糖利用率和还原糖利用率分别为45.62%和74.81%,残留木糖浓度为463.51μg/mL。发酵试验表明酒糟水解液作为碳源发酵生产木糖醇具有可行性。     

肾上腺髓质素对大鼠心肌成纤维细胞胶原合成的影响

目的:观察肾上腺髓质素(ADM)对大鼠心肌成纤维细胞(FBC)胶原合成的影响,并探讨其可能的作用机制。方法:用差速贴壁分离法获得心肌成纤维细胞为材料,用放射免疫法测定细胞培养上清液中I及III型前胶原末端肽(PINP、PCIII)的含量。结果:①ADM呈浓度依赖性抑制FBC的PINP、PCIII分泌;②在AngII存在的情况下,PKA抑制剂能完全阻断ADM抑制细胞PINP、PCIII分泌的作用;③在基础状态和AngII刺激下,PKC及酪氨酸蛋白激酶抑制剂均能增强ADM作用。结论;①ADM能够抑制FBC胶原合成;②ADM抑制FBC胶原合成是通过PKA途径介导。     

鲮鱼鱼皮胶原蛋白酶解物分子量分布与抗氧化性的研究(英文)

[目的]为了研究鲮鱼鱼皮胶原蛋白水解物的分子量的分布及抗氧化活性。[方法]分子量分布采用分子排阻色谱法和基质辅助激光解吸附飞行时间质谱(MALDI-TOF-MS),鱼皮用碱性蛋白酶2709处理。[结果]最佳水解条件为:pH 10.0、反应温度55℃、底物浓度为80 g/L、酶和底物比4%,水解时间3 h。两种方法分析水解产物的相对分子质量分布范围为400~1 800 Da,大多数胶原蛋白短肽的分子量在1 400 Da以下。[结论]结果表明,鱼皮水解物是一种潜在的抗氧化物。     

Intermedin inhibits pulmonary collagen synthesis in rats with pulmonary hypertension induced by high pulmonary blood flow

AIM: To explore the regulatory effect of intermedin (IMD) on pulmonary collagen synthesis and accumulation in rats with pulmonary hypertension induced by high pulmonary blood flow.METHODS: Healthy male SD rats (n=20) were randomly divided into control group (n=7), shunt group (n=7) and shunt with IMD group (n=6). The shunting of abdominal aorta and inferior vena cava was produced in rats of shunt group and shunt with IMD group. After 8 weeks, IMD was administered into the rats of shunt with IMD group subcutaneously by mini-osmotic pump for 2 weeks. Mean pulmonary artery pressure (mPAP), relative medial thickness (RMT) of pulmonary arteries, contents of hydroxyproline, collagen type I and III, bone morphogenetic protein-2 (BMP-2), and the mRNA expression of procollagen I and III in lung tissues were measured and compared. RESULTS: Compared with control group, mPAP and RMT of medium and small pulmonary arteries in the rats of shunt group were significantly increased. Meanwhile, the lung hydroxyproline, collagens I and III and BMP-2 contents, and the mRNA expression of lung procollagen I and III were all significantly increased compared with control group. However, IMD significantly decreased mPAP, alleviated the changes of pulmonary vascular micro-structure, decreased the collagen accumulation and pulmonary tissue homogenate BMP-2 contents, and inhibited the mRNA expression of procollagen I and III in the lung tissue of shunting rats.CONCLUSION: IMD plays a protective role in the development of pulmonary hypertension and pulmonary vascular structural remodeling induced by high blood flow by inhibiting pulmonary collagen synthesis and accumulation, possibly in association with the BMP-2 pathway.     

海参胶原蛋白的提取及其理化性质

胶原蛋白(PSC)是海参蛋白的主要组成,研究其理化性质为海参的进一步利用提供理论基础.以格皮氏海参为原料,采用胃蛋白酶促溶法提取海参胶原蛋白,并通过聚丙烯酰胺凝胶凝胶电泳、氨基酸分析以及傅立叶红外光谱对其理化性质进行研究.结果表明,海参胶原蛋白分子组成为(α1)3,α1的分子量约为150 kD;氨基酸组成以甘氨酸含量最高(6.01％),脯氨酸与羟脯氨酸含量为6.14％,符合水产胶原蛋白特征;傅立叶红外光谱分析结果表明其保持三螺旋结构.     

In vitro release of angiotensin-converting enzyme inhibitors, peroxyl-radical scavengers and antibacterial compounds by enzymatic hydrolysis of glycated gluten

The combined effect of gluten glycation and proteolysis on the release of compounds exhibiting in vitro angiotensin-converting enzyme (ACE) inhibitory, antioxidant and antibacterial activities was investigated. Model systems consisting of wheat gluten and glucose were heated at 120 °C for 45 min, 150 °C for 30 min and 220 °C for 30 min to produce various Maillard reaction products mimicking reactions occurring in bread crusts. Progress of the Maillard reaction was estimated through indirect measurement of Amadori compounds as 2-furoylmethyl-amino acids. Glycation was followed by digestion with Pronase E and ultrafiltration. The anti-hypertensive activity was measured as the ability to inhibit the activity of angiotensin I-converting enzyme involved in hypertension regulation. The Oxygen Radical Absorbance assay was used to measure the peroxyl radical scavenging capacity of the products and their effect on microbial growth of Escherichia coli ATCC 25922 and Staphlococcus aureus ATCC 25923 was also studied. Advanced products of the reaction enhanced the antioxidant and antibacterial properties of gluten hydrolysates and decreased the overall ACE inhibitory activity. Ultrafiltration provided a useful method for separating compounds (< 3000 Da) with ACE inhibitory activity and advanced Maillard reaction products (>3000 Da) which scavenged peroxyl radicals and inhibited the microbial growth.