A new variant of the human α-lactalbumin-oleic acid complex as an anticancer agent for chronic myeloid leukemia

Vivek Singh,Ranjana Singh,Anil Kumar Tripathi,Abbas Ali Mahdi,Dinesh Kumar

doi:10.25122/jml-2021-0065

Vivek Singh, Ranjana Singh + Show 3 more

Open Access

https://doi.org/10.25122/jml-2021-0065

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Abstract

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder of hematopoietic stem cells. Although there have been advancements in treatment, there is still a need to develop a biotherapeutic agent. A new variant of the human alpha-lactalbumin-oleic acid (HALOA) complex has been synthesized, which showed similarities with SNARE. The native α-LA was treated with EDTA to remove Ca2+ ions confirmed by ICP-OES and Arsenazo III to unfold and attain apo structure. The apo LA was mixed with OA in a specific ratio, leading to HALOA complex formation. The conformational state from native to complex was elucidated by circular dichroism (far; 190–260 nm and near; 260–340 nm UV-CD), which confirmed that the complex consists of a majority of turns and β-sheet structure. SDS-PAGE result showed the masking effect of OA on apo α-LA. In the lane of the complex, there was no band detected. However, 1-anilino-8-naphthalene sulfonate (ANS) dye has shown maximum fluorescence intensity with the complex because of the availability of hydrophobic patches, which was further validated by NMR spectroscopy indicating the masking effect of OA on the apo α-LA. The SNARE behavior of the complex (500 nm) has been confirmed by TEM. This new structural variant complex shows anti-tumor activity on chronic myeloid leukemia by targeting the IL-8, survivin, and induces apoptosis through DNA fragmentation, but not against normal cells. Overall, the formulated complex shows that SNARE-like behavior can be used as a promising anti-tumor agent with lower toxicity and maximum bioavailability.

Highlights

Human alpha-Lactalbumin (α-LA) is a calcium-binding protein (14.2 kDa), which has neutraceutical values [1]
Survivin interacts with the non-homologous end joining (NHEJ) DNA repair complex that maintains the integrity of the genome in cancer cells and leads to inflammation (IL-8 production) [24,25,26]
Formulation of the human alpha-lactalbumin-oleic acid (HALOA) complex was done by removing calcium ions from human α-LA (Figure 1 a, b)

Summary

Introduction

Human alpha-Lactalbumin (α-LA) is a calcium-binding protein (14.2 kDa), which has neutraceutical values [1]. A new paradigm focuses on its capacity to interact with oleic acid (OA), forming a protein-lipid complex with a property to trigger apoptosis in tumor cells [2,3,4,5,6,7,8,9]. Few studies [18, 19] have inferred that the mixing process could produce a complex at lower pH conditions that display conformation and biological properties similar to the complex formed by Svanborg through chromatographic procedures. We aimed to (1) make a new variant of the protein-lipid complex at neutral pH for CML treatment and (2) elucidate the effect of the HALOA complex on the markers of apoptosis (total antioxidant capacity, IL-8, and survivin) on leukemia cells

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