The Indian cobra reference genome and transcriptome enables comprehensive identification of venom toxins

Snakebite envenoming is a serious and neglected tropical disease that kills ~100,000 people annually. High-quality, genome-enabled comprehensive characterization of toxin genes will facilitate development of effective humanized recombinant antivenom. We report a de novo near-chromosomal genome assembly of Naja naja, the Indian cobra, a highly venomous, medically important snake. Our assembly has a scaffold N50 of 223.35 Mb, with 19 scaffolds containing 95% of the genome. Of the 23,248 predicted protein-coding genes, 12,346 venom-gland-expressed genes constitute the \u27venom-ome\u27 and this included 139 genes from 33 toxin families. Among the 139 toxin genes were 19 \u27venom-ome-specific toxins\u27 (VSTs) that showed venom-gland-specific expression, and these probably encode the minimal core venom effector proteins. Synthetic venom reconstituted through recombinant VST expression will aid in the rapid development of safe and effective synthetic antivenom. Additionally, our genome could serve as a reference for snake genomes, support evolutionary studies and enable venom-driven drug discovery

Crystalline adenylate kinase from carp muscle

1The concentration of adenylate kinase in carp muscle is about 0.3 mg/g. An improved isolation procedure makes use of a dilute solution of the substrates, ATP and AMP, to elute the enzyme from a phosphocellulose column in overall yields of 60% before crystallization. By the hexokinase–pH-stat assay the specific activity is 3550 units/mg. The preparation has been found to be essentially homogeneous by dodecylsulfate gel electrophoresis, isoelectrofocusing and gel filtration. 2The molecular weight has been determined to be 22000 by several methods. The absorbance of a 1% solution at 280 nm is 6.9 and the isoelectric point by electrofocusing is pH 5.9. 3The crystals of carp adenylate kinase have the space group P4122 or P4322. 4The amino acid composition has been determined. There is no tryptophan, no cystine. There is one amino acid residue each of cysteine and histidine which are at or close to the catalytic center. 5Several peptides derived by tryptic hydrolysis have been isolated and identified with corresponding peptides of porcine adenylate kinase. Consideration is given to histidine and cysteine being a part of the active site

The amino-acid sequence of porcine adenylate kinase from skeletal muscle

1Adenylate kinase (ATP:AMP phosphotransferase) has been purified 490-fold from porcine muscle with a final yield of 60 mg/kg muscle. 2The amino-acid composition is Asp11, Asn2, Thr14, Ser11, Glu19, Gln6, Pro6, Gly19, Ala8, Cys2, Val17, Met6, Ile9, Leu18. Tyr7, Phe5, Lys21, His2, Arg11. 3The protein molecule is a single polypeptide chain of 194 amino-acid residues with an acetyl-methionine at the N-terminus and a lysine residue at the C-terminus. 4Cyanogen bromide cleavage of carboxymethylated adenylate kinase yielded six fragments which were further degraded by using trypsin, chymotrypsin, thermolysin, subtilisin or α-protease. Sequence data on the resulting peptides are summarized in the present report, full details are given in a supplementary paper which has been deposited at CNRS from where copies can be obtained. 5The primary structure of porcine adenylate kinase is: Ac-Met-Glu-Glu-Lys-Leu-Lys-Lys-Ser-Lys-Ile10-Ile-Phe-Val-Val-Gly-Gly-Pro-Gly - Ser-Gly20-Lys-Gly-Thr-Gln-Cys-Glu-Lys-Ile-Val-Gln30-Lys-Tyr-Gly-Tyr-Thr-His-Leu-Ser-Thr-Gly40-Asp-Leu-Leu-Arg-Ala-Glu-Val-Ser-Ser-Gly50-Ser-Ala-Arg-Gly-Lys-Met-Leu-Ser-Glu-Ile60-Met-Glu-Lys-Gly-Gln-Leu-Val-Pro-Leu-Glu70-Thr-Val-Leu-Asp-Met-Leu-Arg-Asp-Ala-Met80-Val-Ala-Lys-Val-Asp-Thr-Ser-Lys-Gly-Phe90-Leu-Ile-Asp-Gly-Tyr-Pro-Arg-Glu-Val-Lys100-Gln-Gly-Glu-Glu-Phe-Glu-Arg-Lys-Ile-Gly110-Gln-Pro-Thr-Leu-Leu-Leu-Tyr-Val-Asp120-Ala-Gly-Pro-Glu-Thr-Met-Thr-Lys-Arg-Leu-Leu130-Lys-Arg-Gly-Glu-Thr-Ser-Gly-Arg-Val-Asp140-Asp-Asn-Glu-Glu-Thr-Ile-Lys-Lys-Arg-Leu150-Glu-Thr-Tyr-Tyr-Lys-Ala-Thr-Glu-Pro-Val160-Ile-Ala-Phe-Tyr-Glu-Lys-Arg-Gly-Ile-Val170-Arg-Lys-Val-Asn-Ala-Glu-Gly-Ser-Val-Asp180-Asp-Val-Phe-Ser-Gln-Val-Cys-Thr-His-Leu190-Asp-Thr-Leu-Lys