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Ajamaluddin Malik

Associate Professor

Associate Professor

كلية العلوم
Building no 5, room no 2A56
المنشورات
مقال فى مجلة
2016

Expression, Purification and Properties of Redox-Sensitive Eye Lens Zeta-Crystallin of Arabian Camel

, Ajamaluddin Malik, Mohammad Rabbani, Nayyar Rabbani, Abdulrahman M. Al-Senaidy, Mohammad A. Alsenaidy . 2016

The high protein concentration, unique composition and complex geometry of the lens makes it transparent. α-, β-, and γ-crystallins are present in all the lenses. In addition, taxon-specific crystallins are present in lenses in bulk quantity. Zeta (ζ)-crystallin is an NADPH-dependent quinone oxidoreductase, which constitutes nearly 10 % of the total eye lens protein in the evolutionary divergent animals (Camel, guinea pig and Japanese frog eye lenses) living in different ecological conditions. ζ -Crystallin is also present in human and other animal lenses but at catalytic amount. The physiological role of γ-crystallin in the eye lens is not well understood, however, truncated ζ-crystallin causes congenital cataract in guinea pig. In earlier study, redox regulated reversible activity of ζ-crystallin was reported. In this study, recombinant camel ζ-crystallin was overexpressed in E.coli and purified to homogeneity. Effect of different concentrations of reducing agent, dithiothretol (DTT) on the quinone oxidoreductase activity of recombinant ζ-crystallin was studied by enzymatic assay. To evaluate the effect of the reducing agent on the ζ-crystallin conformation, we have used far-UV and near-UV CD, intrinsic fluorescence, ANS binding assay and size exclusion chromatography. Our results showed that nearly 50% of the of ζ-crystallin activity was lost at 50 µM DTT. However, no detectable changes in secondary structure were observed. No changes in the tertiary structure and surface hydrophobicity of ζ-crystallin were detected; however, marginal changes were seen at saturating concentration of DTT (1 mM).

رقم المجلد
23
مجلة/صحيفة
Protein & Peptide Letters
الصفحات
573-80
مزيد من المنشورات
publications

Polyphosphate polymers are chains of phosphate monomers chemically
bonded together via phosphoanhydride bonds. They are found in all prokaryotic and
eukaryotic organisms and are among…

بواسطة Ajamaluddin Malik, Javed Masood Khan, Abdulaziz M. Al-Amri, Nojood Altwaijry, Prerna Sharma, Abdullah Alhomida, Priyankar Sen
publications

Phosphate additions in processed foods are a health risk that has been overlooked. This study examined the
effects of a permitted food additive (E452; Sodium Hexametaphosphate (SHMP)) on…

بواسطة Ajamaluddin Malik, Javed Masood Khan, Abdulaziz M. Al-Amri, Nojood Altwaijry, Abdullah S Alhomida, Mohammad Shamsul Ola
2023
publications

Protein aggregation is implicated in different human diseases. It also makes the protein less desirable candidate for industry as they exhibit reduced biological activity. Proteins tend to…

بواسطة Javed Masood Khan, Ajamaluddin Malik, Abdulaziz M. Al-Amri.
2023
تم النشر فى:
Journal of Molecular Liquids