The improvement effect of L-Lys as a chemical chaperone on STZ-induced diabetic rats, protein structure and function

✍ Scribed by A. Jafarnejad; S. Z. Bathaie; M. Nakhjavani; M. Z. Hassan; S. Banasadegh

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 477 KB
• Volume: 24
• Category: Article
• ISSN: 1520-7552
• DOI: 10.1002/dmrr.769

✦ Synopsis

Abstract

Background

L‐Lysine (L‐Lys) has been known as an inhibitor of protein glycation; however, its long‐term use for diabetes treatment considering different aspects of diabetic complication is not seen in the literature. In addition, the effect of L‐Lys, as a chemical chaperone, was considered on protein folding and activity.

Methods

The streptozotocin‐induced diabetic rats were used as a model of diabetes. Normal and diabetic rats were studied for 5 months with and without 0.1% of L‐Lys in drinking water. Serum glucose, advanced glycation end product (AGEs), haemoglobin A~1C~ (HbA~1c~), triglyceride, total cholesterol, HDL‐cholesterol, antioxidant activity, advanced oxidation protein products, fasting insulin level and body weight were determined at 4‐week intervals. Heat shock protein (HSP)70, Lecithin: cholesterol acyl transferase (LCAT) and paraoxonase activity were determined 1 week after diabetes induction (time 0), and after 3 and 5 months. The structure of glycated and normal serum albumin (Alb) in the presence and absence of L‐Lys was also investigated in an in vitro study using spectrofluorometry and circular dichroism (CD).

Results

We found that L‐Lysine therapy prevented diabetic‐ induced increases in Glc, AGE, HbA~1c~, triglyceride, total‐ and LDL‐ cholesterol, and it caused an increase in the decreased antioxidant capacity, HDL‐c, HDL functionality and HSP70. L‐Lys had no effect on serum insulin level. The conformation of Alb changed due to glycation and L‐Lys retained it similar to the native.

Conclusions

L‐Lys, not only as an inhibitor of glycation but also as a chemical chaperone and a protein chaperone inducer, causes effective changes in many parameters of the model animals. However, it is not enough to achieve complete improvement. Copyright © 2007 John Wiley & Sons, Ltd.