Recombinant Giraffa camelopardalis Ribonuclease pancreatic (RNASE1)
Description
Introduction
Recombinant Giraffa camelopardalis Ribonuclease Pancreatic (RNASE1) is a genetically engineered enzyme belonging to the RNase A superfamily, specifically produced for research applications. This protein, derived from the giraffe (Giraffa camelopardalis), shares structural and functional homology with pancreatic ribonucleases across vertebrates, including the well-characterized bovine RNase A . It is synthesized in yeast (Saccharomyces cerevisiae) with a polyhistidine (His) tag for purification, exhibiting >90% purity and suitability for ELISA-based studies .
Sequence and Expression
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Amino Acid Sequence:
The recombinant giraffe RNASE1 comprises residues 1–84 of the mature protein, with the sequence:
FCRKMTQGKC KPVNTFGHES LANVQAVCSQ KKVICKNGLS NCYQSNSAIH YTDCRKTGSS NYPNCAYKTT RAEKRIIVAC EGNL. -
Expression System: Produced in yeast, leveraging eukaryotic post-translational modifications for proper folding .
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Tag: N-terminal His tag for immobilized metal-affinity chromatography (IMAC) purification .
Physicochemical Properties
| Property | Detail |
|---|---|
| Molecular Weight | ~14 kDa (unmodified backbone) |
| Glycosylation | Not reported (likely absent) |
| Purity | >90% (SDS-PAGE) |
| Storage | 20 mM PB, 150 mM NaCl, 10% glycerol (pH 7.4) |
Catalytic Activity
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Substrate Preference: Binds and cleaves single-stranded (ssRNA) and double-stranded RNA (dsRNA), with a predicted neutral pH optimum .
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pH Sensitivity: While giraffe RNASE1’s exact pH optimum is uncharacterized, human RNASE1 homologs exhibit peak activity at pH 7–8, whereas bovine RNase A (RNASE1) functions optimally at pH 6–7 .
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Mechanism: Utilizes cationic residues to interact with RNA’s phosphate backbone, hydrolyzing phosphodiester bonds via a transphosphorylation mechanism .
Comparative Analysis with Vertebrate RNASE1
Current Uses
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ELISA Development: Primary application due to high purity and antigenic consistency .
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Catalytic Studies: Serves as a model for RNase A superfamily evolution, particularly in ruminants .
Potential Therapeutic Relevance
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Anticancer Agents: Engineered human RNASE1 variants evade ribonuclease inhibitor (RI) binding, enabling RNA degradation in cancer cells . While giraffe RNASE1’s RI interaction is unstudied, structural homology suggests similar engineering potential.
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Immunomodulation: RNASE1 homologs influence macrophage polarization in tumor microenvironments, suggesting roles in immunotherapy .
Evolutionary Context
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Dietary Adaptation: RNASE1 duplication in ruminants (e.g., cows) correlates with foregut fermentation, enhancing symbiotic bacterial RNA digestion . Giraffes, as foregut fermenters, likely retain RNASE1 for similar functions, though direct evidence is lacking.
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Gene Loss in Carnivores: Cetaceans (whales, dolphins) lost pancreatic RNASE1 copies post-dietary shift to carnivory, underscoring its digestive role in herbivores .
