Antarctic krill (Euphausia superba) might have specific peptides that chelate iron ions and are iron carriers. In this study, iron-binding peptides were isolated from Antarctic krill using enzymatic (trypsin) hydrolysis and immobilized metal affinity chromatography (IMAC); the binding mode and surface morphology of Antarctic krill peptides (AKP)-iron complexes as well as their iron delivery behavior in the gastrointestinal tract were investigated. Results showed that the AKP bound 79.3% of available iron from the enzymatic hydrolysis for 180 min. The contents of negatively-charged amino acids (Asp and Glu) on the AKP showed a positive correlation (r = 0.80) with iron-binding activities (the data includes Asn and Gln), while positively-charged amino acids showed a negative correlation (r = −0.83). Moreover, His, Ser and Thr on the AKP were also involved in the iron-binding activities. Iron-binding peptides from Antarctic krill hydrolysates, isolated using IMAC-Fe³⁺ and identified using HPLC-MS/MS, showed a mass of 712–2451 Da, and were enriched in Asp (Asn), Glu (Gln), His, Ser or Thr. The iron ions mainly bound to carboxyl groups of AKP, thus forming nano-scale, spherical particles. The iron nanocarriers formed by AKP showed a significant iron transport activity after simulated gastrointestinal digestion, as compared to FeSO₄ (P < 0.05). The results suggested that the AKP-iron nanocomposite has the potential to be a nutraceutical supplement for improving iron absorption.

南极磷虾（Euphausia superba）可能具有螯合铁离子的特定肽，并且是铁载体。在这项研究中，使用酶（胰蛋白酶）水解和固定化金属亲和色谱法（IMAC）从南极磷虾中分离出铁结合肽。研究了南极磷虾肽（AKP）-铁配合物的结合方式和表面形态，以及它们在胃肠道中的铁传递行为。结果表明，AKP结合了180分钟来自酶促水解的79.3％的可用铁。AKP上带负电荷的氨基酸（Asp和Glu）的含量与铁结合活性（数据包括Asn和Gln）呈正相关（r = 0.80），而带正电荷的氨基酸呈负相关（R = 0.80）。 r = -0.83）。而且，他的 AKP上的Ser和Thr也参与了铁结合活动。使用IMAC-Fe分离的南极磷虾水解产物中的铁结合肽³⁺并使用HPLC-MS / MS鉴定，质量为712–2451 Da，并富含Asp（Asn），Glu（Gln），His，Ser或Thr。铁离子主要结合到AKP的羧基上，从而形成纳米级的球形颗粒。与FeSO ₄相比，由AKP形成的铁纳米载体在模拟胃肠道消化后显示出显着的铁转运活性（P  <0.05）。结果表明，AKP-铁纳米复合材料具有作为改善铁吸收的营养保健品的潜力。