Aghajanyan Armen E, Hambardzumyan Artur A, Hovsepyan Anichka S, Asaturian Rafael A, Vardanyan Andranik A, Saghiyan Ashot A
JSC, Institute of Biotechnology, 14.Gyurjian str. Yerevan, 375056, Armenia.
Pigment Cell Res. 2005 Apr;18(2):130-5. doi: 10.1111/j.1600-0749.2005.00211.x.
Melanins are widely used in medicine, pharmacology, cosmetics and other fields. Although several technologies for the purification of water-insoluble dioxyphenylalanine (DOPA) melanins have been described, a source of water-soluble melanin is highly desirable. Here we describe an effective procedure for the isolation and purification of water-soluble melanin using the culture medium of Bacillus thuringiensis subsp. galleriae strain K1. Water-soluble melanin from this organism has an isoelectric point (pI=3.0-3.2) and was purified optimally by adsorbtion using the IA-1r resin and elution as a concentrated solution. The purified melanin obtained exhibited a similar infra-red absorbtion spectrum to synthetic melanin and contained quinolic and phenolic structures and an amino acid content of around 20% after acid hydrolysis. The molecular weight of the purified melanin determined by SDS-PAGE was 4 kDa and the electromagnetic spin resonance spectrum of the purified microbial melanin was a slightly asymmetric singlet without hyperfine structure with about 7 Gauss width of the line between points of the maximum incline and g=2.006. The concentration of paramagnetic centers in melanin is 0.21x10(18) spin/g. The results obtained provide a rapid, simple and inexpensive method for the large scale purification of water soluble melanin that may have widespread applications.
黑色素广泛应用于医学、药理学、化妆品及其他领域。尽管已有多种纯化水不溶性二羟基苯丙氨酸（DOPA）黑色素的技术，但水溶性黑色素的来源仍备受期待。在此，我们描述了一种利用苏云金芽孢杆菌蜡螟亚种K1菌株的培养基分离纯化水溶性黑色素的有效方法。该生物体产生的水溶性黑色素的等电点为（pI = 3.0 - 3.2），通过使用IA - 1r树脂吸附并以浓缩溶液洗脱可实现最佳纯化。所获得的纯化黑色素呈现出与合成黑色素相似的红外吸收光谱，含有喹啉和酚类结构，酸水解后氨基酸含量约为20%。通过SDS - PAGE测定，纯化黑色素的分子量为4 kDa，纯化后的微生物黑色素的电子自旋共振光谱是一个略微不对称的单峰，没有超精细结构。在最大斜率点之间的线宽约为7高斯，g = 2.006。黑色素中顺磁中心的浓度为0.21×10(18)自旋/克。所得结果为大规模纯化水溶性黑色素提供了一种快速、简单且廉价的方法，该方法可能具有广泛的应用。
