Biochemistry of heat shock protein 47 (HSP47)

Heat shock protein 47 (HSP47) is a molecular chaperone crucial for collagen biosynthesis. It is a single-substrate chaperone, and binds only to collagen. ‘Knock-out’ of the hsp47 gene has been shown to impair the secretion of correctly folded collagen triple helix molecules, leading to embryonic lethality in mice. HSP47 belongs to the well characterised ‘serpin’ superfamily, but the chaperone itself is not fully understood in terms of its molecular interactions.

My interest is to elucidate the specific mechanism that governs HSP47 binding to, and release from collagen, at the molecular level. The mechanism is known as the ‘pH-switch mechanism’. I focus the investigation on histidine (His) residues, as the HSP47-collagen dissociation pH is similar to the pKa of the imidazole side chain.

Several biochemical and chemical techniques are involved, such as:
-protein homology modelling,
-site directed mutagenesis,
-affinity chromatography,
-protein separation and immunodetection,
-size exclusion chromatography (SEC),
-protein circular dichroism,
-fluorescence spectroscopy (intrinsic tryptophan and anisotropy),
-peptide synthesis and coupling,
-binding assays,
-fluorescence microscopy

I am also interested in further studying the interactions between HSP47 and collagen, towards application in drug development.

Collaborators:
1. Dr. Takayuki Homma, Kyoto University.
2. Dr. Normala Abd Latip, Faculty of Pharmacy, UiTM.
3. Dr. Siti Hamimah Syeikh Abdul Kadir, Institute for Medical Molecular Biotechnology, UiTM.

Bacterial Biohydrogen Production and Bioelectrochemical Systems

The world’s energy supply is the hotly debated issue nowadays. There are many ways to decrease the reliance on conventional fossil fuels, and microbes as energy factory is among the promising ones. The challenge of using microbes and biological materials is to obtain efficient and cost-effective fuel production. Currently we are investigating potential biohydrogen producing microbes from various sources. We are also using 16S rRNA amplicon sequencing to look into the microbial community dynamics in biohydrogen bioreactor.

In addition, we are investigating microbial fuel cells (MFC) and microbial electrolysis cells (MEC) for higher energy recovery and substrate degradation.

Collaborators:
1. Assoc. Prof. Dr. Madihah Md Salleh, Department of Biosciences, Faculty of Science (FS), UTM.
2. Dr. Adibah Yahya, Department of Biosciences, FS, UTM.
3. Dr. Norahim Ibrahim, Department of Biosciences, FS, UTM.
4. Dr. Wan Rosmiza Zana Wan Dagang, Department of Biosciences, FS, UTM.