Purification and Production of Novel Angiotensin I-Converting Enzyme (ACE) Inhibitory Bioactive Peptides Derived from Fermented Goat Milk

International Journal of Peptide Research and Therapeutics - In the study, five different Lactobacillus cultures i.e. L. rhamnosus (NK2) (KR080695), L. casei (NK9) (KR732325), L. fermentum (M5)...     

Evolution of Stronger SARS-CoV-2 Variants as Revealed Through the Lens of Molecular Dynamics Simulations

The Protein Journal - Using molecular dynamics simulations, the protein–protein interactions of the receptor-binding domain of the wild-type and seven variants of the severe acute respiratory...     

Comparison of intrinsic dynamics of cytochrome p450 proteins using normal mode analysis

Cytochrome P450 enzymes are hemeproteins that catalyze the monooxygenation of a wide‐range of structurally diverse substrates of endogenous and exogenous origin. These heme monooxygenases receive electrons from NADH/NADPH via electron transfer proteins. The cytochrome P450 enzymes, which constitute a diverse superfamily of more than 8,700 proteins, share a common tertiary fold but < 25% sequence identity. Based on their electron transfer protein partner, cytochrome P450 proteins are classified into six broad classes. Traditional methods of protein classification are based on the canonical paradigm that attributes proteins’ function to their three‐dimensional structure, which is determined by their primary structure that is the amino acid sequence. It is increasingly recognized that protein dynamics play an important role in molecular recognition and catalytic activity. As the mobility of a protein is an intrinsic property that is encrypted in its primary structure, we examined if different classes of cytochrome P450 enzymes display any unique patterns of intrinsic mobility. Normal mode analysis was performed to characterize the intrinsic dynamics of five classes of cytochrome P450 proteins. The present study revealed that cytochrome P450 enzymes share a strong dynamic similarity (root mean squared inner product > 55% and Bhattacharyya coefficient > 80%), despite the low sequence identity (< 25%) and sequence similarity (< 50%) across the cytochrome P450 superfamily. Noticeable differences in C_α atom fluctuations of structural elements responsible for substrate binding were noticed. These differences in residue fluctuations might be crucial for substrate selectivity in these enzymes.     

Strong and weak zinc binding sites in human zinc-α2-glycoprotein

Zinc-α2-glycoprotein (ZAG) is an adipokine with an MHC class I-like protein fold. Even though zinc causes ZAG to precipitate from plasma during protein purification, no zinc binding has been identified to date. Using mass spectrometry, we demonstrated that ZAG contains one strongly bound zinc ion, predicted to lie close to the α1 and α2 helical groove. UV, CD and fluorescence spectroscopies detected weak zinc binding to holo-ZAG, which can bind up to 15 zinc ions. Zinc binding to 11-(dansylamino) undecanoic acid was enhanced by holo-ZAG. Zinc binding may be important for ZAG binding to fatty acids and the β-adrenergic receptor.     

Pose estimation in automated visual inspection using genetic algorithm

In this paper, we propose a genetic algorithm based approach to determine the pose of an object in Automated Visual Inspection having three degrees of freedom. We have investigated the effect of noise at 20 dB SNR and also mismatch resulting from incorrect correspondences between the object space points and the image space points, on the estimation of pose parameters. The maximum error in translation parameters is less than 0.45 cm and rotational error is less than 0.2 degree at 20 dB SNR. The error in parameter estimation is insignificant upto 7 pairs of mismatched points out of 24 points in object space and the results skyrockets when 8 or more pairs of points are mismatched. We have compared our result with that obtained by least square technique and it shows that GA based method outperform the gradient based technique when the number of vertices of the object to be inspected is small. These results have clearly established the robustness of GA in estimating the pose of an object with small number of vertices in automated visual inspection.     

<Emphasis Type="Italic">In Silico</Emphasis> and <Emphasis Type="Italic">In vitro</Emphasis> Analysis of Novel Angiotensin I-Converting Enzyme (ACE) inhibitory Bioactive Peptides Derived from Fermented Camel Milk (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>)

In this study, Lactobacillus bulgaricus NCDC (09) and Lactobacillus fermentum TDS030603 (LBF) were evaluated for their ACE-inhibitory activity and peptides production under optimized conditions from fermented camel milk (Camelus dromedarius). Lactic cultures were evaluated for their pepX activity, proteolytic activity and ACE-inhibitory activity. 09 culture exhibited higher PepX and ACE-inhibitory activity than LBF. 2% rate of inoculation and 12 h of incubation were optimized on the basis of pepX and proteolytic activity. Purified peptides from fermented camel milk were characterized by amino acids profiling through the search in BlastP, Protein information resource (PIR) databases. ACE-inhibitory activity of different peptides from fermented camel milk were also confirmed by the database of antihypertensive peptides (AHTPDB). Fermented camel milk produced by Lactobacillus cultures could be a novel source of ACE-inhibitory peptides.     

Impact of Proteolytic <Emphasis Type="Italic">Lactobacillus helveticus</Emphasis> MTCC5463 on Production of Bioactive Peptides Derived from Honey Based Fermented Milk

In this study, Lactobacillus helveticus MTCC5463 was evaluated for its proteolytic activity and production of bioactive peptides during fermentation of honey supplemented milk under specified growth conditions. Generally, lactic acid bacteria have a strong proteolytic system. However, L. helveticus MTCC5463 showed maximum proteolytic activity at 4 % level of honey supplementation compared to 6 % and control. Similarly, water soluble extract derived from fermented honey based milks exhibited different level of bioactive peptides productions during fermentation. L. helveticus MTCC5463 showed maximum peptides production at 4 % level of honey supplementation compared to control during HPLC analysis and LC–MS analysis.     

Comparative modeling of the phosphatase and kinase domains of protein tyrosine phosphatase and insulin receptor kinase from Drosophila melanogaster (DPTP61fm), and a computational study of their mutual interactions.

The components and functions of the insulin receptor kinase signaling pathway have been conserved in a broad range of Metazoa ranging from mammals to insects and nematodes. There is a high degree of sequence homology and functional similarity between the human insulin receptor kinase (IRK) and the drosophila (Drosophila melanogaster) form (DIRK) of this enzyme. Similarly, a high degree of homology exists between human protein tyrosine phosphatase 1B (PTP1B) (which directly regulates IRK) and its drosophila counterpart DPTP61F (DPTP). However, genetic and biochemical studies have yet to demonstrate that DPTP61F acts in the DIRK pathway. Comparative structural modeling techniques using the known structures of human IRK and PTP1B as templates have yielded structures for the drosophila enzymes. The derived structures confirm that there is a high level of structural conservation at the tertiary level. Association of the DIRK and DPTP enzymes with each other was then investigated with a view to ascertaining whether DIRK might be a substrate of the DPTP. Evaluation of the interaction surfaces, including hydrophobic patch, shape, hydrogen bonding, and electrostatic compatibility, strongly suggested that the drosophila insulin receptor is a substrate of the DPTP. The interaction surfaces of the human and drosophila enzymes are structurally similar, although changes in critical residues modify possible electrostatic and hydrogen-bonding interactions. This suggests that in the mixed systems, DPTP-IRK or PTP1B-DIRK, the kinase domain will be a comparatively poor substrate for phosphatase activity when compared with the native systems.