Effect of thaw temperatures in reducing enzyme activity in human thyroid tissues

Area of Science:

• Proteomics
• Biochemistry
• Molecular Biology

Background:

• Protein degradation in tissues is a major challenge in proteomics.
• Frozen storage (liquid nitrogen, -80°C) aims to preserve proteins.
• Thawing protocols for frozen tissues vary, with limited data on enzymatic inactivation.

Purpose of the Study:

• To investigate the impact of different thawing temperatures on enzymatic activity in human tissue lysates.
• To evaluate the effectiveness of high-temperature thawing in reducing enzymatic degradation without inhibitors.

Main Methods:

• Frozen human thyroid tissues (benign, malignant, normal) were thawed at 4°C, 37°C, and 95°C.
• Tyrosine phosphatase and phosphatase and tensin homolog activity assays were performed on lysates.
• Analyses were conducted without the addition of enzymatic inhibitors.

Main Results:

• High-temperature thawing (95°C) significantly reduced enzymatic activity across benign, malignant, and diseased tissues.
• Enzyme inactivation varied depending on the specific enzyme in normal tissues.
• No inhibitors were used, demonstrating the efficacy of high-temperature thawing alone.

Conclusions:

• High-temperature thawing is a promising method to mitigate enzymatic degradation in frozen tissue lysates.
• This approach can enhance downstream non-enzymatic analyses, particularly for diseased and neoplastic tissues.
• Further research may optimize thawing protocols for specific enzymatic targets.